TY - JOUR
A1 - Werger, Luise
A1 - Bergmann, Joana
A1 - Weber, Ewald
A1 - Heinze, Johannes
T1 - Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects
JF - Annals of Botany Plants
N2 - Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant–soil feedbacks—PSFs). However, information on wind effects on fine root morphology is scarce and the extent to which wind changes plant–soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant–soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant–soil interactions under changing environmental conditions.
KW - Wind
KW - root traits
KW - root morphology
KW - specific root length
KW - plant–soil feedback
Y1 - 2020
U6 - https://doi.org/10.1093/aobpla/plaa050
SN - 2041-2851
VL - 12
IS - 5
PB - Oxford University Press
CY - Oxford
ER -
TY - GEN
A1 - Werger, Luise
A1 - Bergmann, Joana
A1 - Weber, Ewald
A1 - Heinze, Johannes
T1 - Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant–soil feedbacks—PSFs). However, information on wind effects on fine root morphology is scarce and the extent to which wind changes plant–soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant–soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant–soil interactions under changing environmental conditions.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1019
KW - Wind
KW - root traits
KW - root morphology
KW - specific root length
KW - plant–soil feedback
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-484092
SN - 1866-8372
IS - 1019
ER -
TY - JOUR
A1 - Chorus, Ingrid
A1 - Spijkerman, Elly
T1 - What Colin Reynolds could tell us about nutrient limitation, N:P ratios and eutrophication control
JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica
N2 - Colin Reynolds exquisitely consolidated our understanding of driving forces shaping phytoplankton communities and those setting the upper limit to biomass yield, with limitation typically shifting from light in winter to phosphorus in spring. Nonetheless, co-limitation is frequently postulated from enhanced growth responses to enrichments with both N and P or from N:P ranging around the Redfield ratio, concluding a need to reduce both N and P in order to mitigate eutrophication. Here, we review the current understanding of limitation through N and P and of co-limitation. We conclude that Reynolds is still correct: (i) Liebig's law of the minimum holds and reducing P is sufficient, provided concentrations achieved are low enough; (ii) analyses of nutrient limitation need to exclude evidently non-limiting situations, i.e. where soluble P exceeds 3-10 mu g/l, dissolved N exceeds 100-130 mu g/l and total P and N support high biomass levels with self-shading causing light limitation; (iii) additionally decreasing N to limiting concentrations may be useful in specific situations (e.g. shallow waterbodies with high internal P and pronounced denitrification); (iv) management decisions require local, situation-specific assessments. The value of research on stoichiometry and co-limitation lies in promoting our understanding of phytoplankton ecophysiology and community ecology.
KW - phytoplankton
KW - nitrogen limitation
KW - redfield ratio
KW - co-limitation
KW - enrichment experiments
Y1 - 2020
U6 - https://doi.org/10.1007/s10750-020-04377-w
SN - 0018-8158
SN - 1573-5117
VL - 848
IS - 1
SP - 95
EP - 111
PB - Springer Nature
CY - Berlin
ER -
TY - GEN
A1 - Chorus, Ingrid
A1 - Spijkerman, Elly
T1 - What Colin Reynolds could tell us about nutrient limitation, N:P ratios and eutrophication control
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Colin Reynolds exquisitely consolidated our understanding of driving forces shaping phytoplankton communities and those setting the upper limit to biomass yield, with limitation typically shifting from light in winter to phosphorus in spring. Nonetheless, co-limitation is frequently postulated from enhanced growth responses to enrichments with both N and P or from N:P ranging around the Redfield ratio, concluding a need to reduce both N and P in order to mitigate eutrophication. Here, we review the current understanding of limitation through N and P and of co-limitation. We conclude that Reynolds is still correct: (i) Liebig's law of the minimum holds and reducing P is sufficient, provided concentrations achieved are low enough; (ii) analyses of nutrient limitation need to exclude evidently non-limiting situations, i.e. where soluble P exceeds 3-10 mu g/l, dissolved N exceeds 100-130 mu g/l and total P and N support high biomass levels with self-shading causing light limitation; (iii) additionally decreasing N to limiting concentrations may be useful in specific situations (e.g. shallow waterbodies with high internal P and pronounced denitrification); (iv) management decisions require local, situation-specific assessments. The value of research on stoichiometry and co-limitation lies in promoting our understanding of phytoplankton ecophysiology and community ecology.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1344
KW - phytoplankton
KW - nitrogen limitation
KW - redfield ratio
KW - co-limitation
KW - enrichment experiments
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-541979
SN - 1866-8372
IS - 1
ER -
TY - THES
A1 - Crawford, Michael Scott
T1 - Using individual-based modeling to understand grassland diversity and resilience in the Anthropocene
N2 - The world’s grassland systems are increasingly threatened by anthropogenic change. Susceptible to a variety of different stressors, from land-use intensification to climate change, understanding the mechanisms driving the maintenance of these systems’ biodiversity and stability, and how these mechanisms may shift under human-mediated disturbance, is thus critical for successfully navigating the next century. Within this dissertation, I use an individual-based and spatially-explicit model of grassland community assembly (IBC-grass) to examine several processes, thought key to understanding their biodiversity and stability and how it changes under stress. In the first chapter of my thesis, I examine the conditions under which intraspecific trait variation influences the diversity of simulated grassland communities. In the second and third chapters of my thesis, I shift focus towards understanding how belowground herbivores influence the stability of these grassland systems to either a disturbance that results in increased, stochastic, plant mortality, or eutrophication.
Intraspecific trait variation (ITV), or variation in trait values between individuals of the same species, is fundamental to the structure of ecological communities. However, because it has historically been difficult to incorporate into theoretical and statistical models, it has remained largely overlooked in community-level analyses. This reality is quickly shifting, however, as a consensus of research suggests that it may compose a sizeable proportion of the total variation within an ecological community and that it may play a critical role in determining if species coexist. Despite this increasing awareness that ITV matters, there is little consensus of the magnitude and direction of its influence. Therefore, to better understand how ITV changes the assembly of grassland communities, in the first chapter of my thesis, I incorporate it into an established, individual-based grassland community model, simulating both pairwise invasion experiments as well as the assembly of communities with varying initial diversities. By varying the amount of ITV in these species’ functional traits, I examine the magnitude and direction of ITV’s influence on pairwise invasibility and community coexistence. During pairwise invasion, ITV enables the weakest species to more frequently invade the competitively superior species, however, this influence does not generally scale to the community level. Indeed, unless the community has low alpha- and beta- diversity, there will be little effect of ITV in bolstering diversity. In these situations, since the trait axis is sparsely filled, the competitively inferior may suffer less competition and therefore ITV may buffer the persistence and abundance of these species for some time.
In the second and third chapters of my thesis, I model how one of the most ubiquitous trophic interactions within grasslands, herbivory belowground, influences their diversity and stability. Until recently, the fundamental difficulty in studying a process within the soil has left belowground herbivory “out of sight, out of mind.” This dilemma presents an opportunity for simulation models to explore how this understudied process may alter community dynamics. In the second chapter of my thesis, I implement belowground herbivory – represented by the weekly removal of plant biomass – into IBC-grass. Then, by introducing a pulse disturbance, modelled as the stochastic mortality of some percentage of the plant community, I observe how the presence of belowground herbivores influences the resistance and recovery of Shannon diversity in these communities. I find that high resource, low diversity, communities are significantly more destabilized by the presence of belowground herbivores after disturbance. Depending on the timing of the disturbance and whether the grassland’s seed bank persists for more than one season, the impact of the disturbance – and subsequently the influence of the herbivores – can be greatly reduced. However, because human-mediated eutrophication increases the amount of resources in the soil, thus pressuring grassland systems, our results suggest that the influence of these herbivores may become more important over time.
In the third chapter of my thesis, I delve further into understanding the mechanistic underpinnings of belowground herbivores on the diversity of grasslands by replicating an empirical mesocosm experiment that crosses the presence of herbivores above- and below-ground with eutrophication. I show that while aboveground herbivory, as predicted by theory and frequently observed in experiments, mitigates the impact of eutrophication on species diversity, belowground herbivores counterintuitively reduce biodiversity. Indeed, this influence positively interacts with the eutrophication process, amplifying its negative impact on diversity. I discovered the mechanism underlying this surprising pattern to be that, as the herbivores consume roots, they increase the proportion of root resources to root biomass. Because root competition is often symmetric, herbivory fails to mitigate any asymmetries in the plants’ competitive dynamics. However, since the remaining roots have more abundant access to resources, the plants’ competition shifts aboveground, towards asymmetric competition for light. This leads the community towards a low-diversity state, composed of mostly high-performance, large plant species. We further argue that this pattern will emerge unless the plants’ root competition is asymmetric, in which case, like its counterpart aboveground, belowground herbivory may buffer diversity by reducing this asymmetry between the competitively superior and inferior plants.
I conclude my dissertation by discussing the implications of my research on the state of the art in intraspecific trait variation and belowground herbivory, with emphasis on the necessity of more diverse theory development in the study of these fundamental interactions. My results suggest that the influence of these processes on the biodiversity and stability of grassland systems is underappreciated and multidimensional, and must be thoroughly explored if researchers wish to predict how the world’s grasslands will respond to anthropogenic change. Further, should researchers myopically focus on understanding central ecological interactions through only mathematically tractable analyses, they may miss entire suites of potential coexistence mechanisms that can increase the coviability of species, potentially leading to coexistence over ecologically-significant timespans. Individual-based modelling, therefore, with its focus on individual interactions, will prove a critical tool in the coming decades for understanding how local interactions scale to larger contexts, and how these interactions shape ecological communities and further predicting how these systems will change under human-mediated stress.
N2 - Grasland ist durch anthropogene Veränderungen bedroht. Im Rahmen dieser Dissertation verwende ich ein individuelles und räumlich-explizites Modell der Grasland-Gemeinschaftsversammlung (IBC-Gras), um verschiedene Prozesse zu untersuchen, die als Schlüssel zum Verständnis ihrer Biodiversität und Stabilität und deren Veränderung unter Stress gelten. Im ersten Kapitel meiner Dissertation untersuche ich die Bedingungen, unter denen eine intraspezifische Merkmalsvariation die Vielfalt der simulierten Graslandgemeinschaften beeinflusst. Im zweiten und dritten Kapitel meiner Dissertation verlege ich den Schwerpunkt auf das Verständnis, wie unterirdische Pflanzenfresser die Stabilität dieser Grünlandsysteme beeinflussen, und zwar entweder durch eine Störung, die zu erhöhter, stochastischer Pflanzensterblichkeit oder Eutrophierung führt.
Intraspezifische Merkmalsvariation (ITV) oder Variation der Merkmalswerte zwischen Individuen derselben Art ist für die Struktur ökologischer Gemeinschaften von grundlegender Bedeutung. Da sie sich jedoch historisch gesehen nur schwer in theoretische und statistische Modelle einbauen lässt, wurde sie bei Analysen auf Gemeindeebene weitgehend übersehen. Diese Realität ändert sich jedoch schnell, da ein Forschungskonsens darauf hindeutet, dass sie einen beträchtlichen Anteil der Gesamtvariation innerhalb einer ökologischen Gemeinschaft ausmachen kann und dass sie eine entscheidende Rolle bei der Bestimmung der Koexistenz von Arten spielen kann. Trotz dieses zunehmenden Bewusstseins, dass das ITV von Bedeutung ist, gibt es kaum einen Konsens über das Ausmaß und die Richtung seines Einflusses. Um besser zu verstehen, wie ITV die Zusammensetzung von Grünlandgesellschaften verändert, beziehe ich daher im ersten Kapitel meiner Dissertation diese in ein etabliertes, auf dem Individuum basierendes Modell der Grünlandgesellschaften ein. Indem ich die Menge an ITV in den funktionellen Merkmalen dieser Arten variiere, untersuche ich das Ausmaß und die Richtung des Einflusses von ITV auf die paarweise Unsichtbarkeit und die Koexistenz von Gemeinschaften.
Im zweiten und dritten Kapitel meiner Dissertation modelliere ich, wie eine der allgegenwärtigsten trophischen Interaktionen innerhalb von Grasland, die Pflanzenfresserei unter der Erde, deren Vielfalt und Stabilität beeinflusst. Bis vor kurzem hat die grundlegende Schwierigkeit, einen Prozess im Boden zu untersuchen, dazu geführt, dass Pflanzenfresser unter der Erde "aus den Augen, aus dem Sinn" geraten sind. Dieses Dilemma bietet eine Gelegenheit für Simulationsmodelle zu erforschen, wie dieser noch nicht untersuchte Prozess die Dynamik von Gemeinschaften verändern kann. Im zweiten Kapitel meiner Dissertation implementiere ich unterirdische Pflanzenfresserei - repräsentiert durch die wöchentliche Entfernung von pflanzlicher Biomasse - in IBC-Gras. Dann beobachte ich durch die Einführung einer Pulsstörung, die als stochastische Mortalität eines gewissen Prozentsatzes der Pflanzengemeinschaft modelliert wird, wie die Anwesenheit von unterirdischen Pflanzenfressern die Resistenz und Erholung der Shannon-Diversität in diesen Gemeinschaften beeinflusst. Ich stelle fest, dass Gemeinschaften mit hohen Ressourcen und geringer Diversität durch die Anwesenheit von unterirdischen Pflanzenfressern nach einer Störung wesentlich stärker destabilisiert werden. Abhängig vom Zeitpunkt der Störung und davon, ob die Saatgutbank des Graslandes länger als eine Saison besteht, können die Auswirkungen der Störung - und damit der Einfluss der Pflanzenfresser - stark reduziert werden. Im dritten Kapitel meiner Dissertation vertiefe ich das Verständnis der mechanistischen Grundlagen der unterirdischen Herbivoren für die Diversität von Grasland, indem ich ein empirisches Mesokosmos-Experiment repliziere, das die Anwesenheit von Herbivoren über- und unterirdisch mit Eutrophierung kreuzt. Ich zeige, dass, während oberirdische Pflanzenfresser, wie von der Theorie vorhergesagt und häufig in Experimenten beobachtet, die Auswirkungen der Eutrophierung auf die Artenvielfalt abschwächen, unterirdische Pflanzenfresser die Artenvielfalt kontraintuitiv reduzieren. Tatsächlich interagiert dieser Einfluss positiv mit dem Eutrophierungsprozess und verstärkt seine negativen Auswirkungen auf die Vielfalt.
Ich schließe meine Dissertation mit einer Erörterung der Auswirkungen meiner Forschung auf den Stand der Technik bei der Variation intraspezifischer Merkmale und der unterirdischen Pflanzenfresserei, wobei der Schwerpunkt auf der Notwendigkeit einer vielfältigeren Theorieentwicklung bei der Untersuchung dieser grundlegenden Wechselwirkungen liegt. Meine Ergebnisse deuten darauf hin, dass der Einfluss dieser Prozesse auf die biologische Vielfalt und Stabilität von Graslandsystemen unterschätzt wird und mehrdimensional ist und gründlich erforscht werden muss, wenn Forscher vorhersagen wollen, wie die Grasländer der Welt auf anthropogene Veränderungen reagieren werden. Sollten sich Forscherinnen und Forscher darüber hinaus myopisch darauf konzentrieren, zentrale ökologische Wechselwirkungen nur durch mathematisch nachvollziehbare Analysen zu verstehen, könnten sie ganze Suiten potenzieller Koexistenzmechanismen übersehen, die die Begehrlichkeit von Arten erhöhen können und möglicherweise zu einer Koexistenz über ökologisch signifikante Zeitspannen hinweg führen. Daher wird sich die individuenbasierte Modellierung mit ihrem Schwerpunkt auf individuellen Interaktionen in den kommenden Jahrzehnten als ein entscheidendes Instrument erweisen, um zu verstehen, wie lokale Interaktionen sich auf größere Zusammenhänge ausdehnen und wie diese Interaktionen ökologische Gemeinschaften formen, und um weiter vorherzusagen, wie sich diese Systeme unter vom Menschen verursachtem Stress verändern werden.
T2 - Einsatz von individualbasierten Modellen zum Verständnis der Grasland-Diversität und -Resilienz im Anthropozän
KW - intraspecific trait variation
KW - eutrophication
KW - belowground herbivory
KW - grassland
KW - ecological modelling
KW - intraspezifische Merkmalsvariation
KW - Eutrophierung
KW - Grasland
KW - ökologische Modellierung
KW - unterirdische Pflanzenfresser
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-479414
ER -
TY - JOUR
A1 - Gomula, Aleksandra
A1 - Nowak-Szczepanska, Natalia
A1 - Hermanussen, Michael
A1 - Scheffler, Christiane
A1 - Koziel, Slawomir
T1 - Trends in growth and developmental tempo in boys aged 7 to 18 years between 1966 and 2012 in Poland
JF - American journal of human biology : the official journal of the Human Biology Council
N2 - Objectives:
To assess trends in growth in different developmental periods and trends in developmental tempo in Polish boys between 1966 and 2012.
Methods:
Data on 34 828 boys aged 7 to 18 years were collected during Polish Anthropological Surveys conducted in 1966, 1978, 1988, and 2012. Biological parameters, related to onset of adolescent growth spurt (OGS) and peak height velocity (PHV), were derived from a Preece-Baines 1 model (PB1). Childhood (height at 7 years of age), pre-adolescent (height at OGS) and adolescent growth (adult height minus height at OGS) were identified.
Results:
Positive secular trend between 1966 and 2012 in adult height accounted for, on average, 1.5 cm/decade, with varying intensity between the Surveys. Decline in both age at OGS and APHV between 1966 and 2012 (1.5 and 1.4 years, respectively) indicated an acceleration in developmental tempo, on average, by 0.3 year/decade. Increases in the contribution to the trend in adult height gained during growth in particular developmental periods between 1966 and 2012 were as followed-childhood: 0.6%, pre-adolescent growth: -3.1%, adolescent growth: 3.1%.
Conclusions:
Secular trend in developmental tempo and growth among boys reflects changes in living conditions and socio-political aspirations in Poland during nearly 50 years. Acceleration in tempo is already visible at age at OGS, whereas the trend in adult height occurs largely during adolescence, pointing to different regulation of developmental tempo and growth in body height. This finding emphasizes the importance of extending public health intervention into children's growth up until adolescence.
Y1 - 2020
U6 - https://doi.org/10.1002/ajhb.23548
SN - 1042-0533
SN - 1520-6300
VL - 33
IS - 6
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Apanasewicz, Anna
A1 - Groth, Detlef
A1 - Scheffler, Christiane
A1 - Hermanussen, Michael
A1 - Piosek, Magdalena
A1 - Wychowaniec, Patrycja
A1 - Babiszewska, Magdalena
A1 - Barbarska, Olga
A1 - Ziomkiewicz, Anna
T1 - Traumatized women’s infants are bigger than children of mothers without traumas
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger
N2 - Life history theory predicts that experiencing stress during the early period of life will result in accelerated growth and earlier maturation. Indeed, animal and some human studies documented a faster pace of growth in the offspring of stressed mothers. Recent advances in epigenetics suggest that the effects of early developmental stress might be passed across the generations. However, evidence for such intergenerational transmission is scarce, at least in humans. Here we report the results of the study investigating the association between childhood trauma in mothers and physical growth in their children during the first months of life. Anthropometric and psychological data were collected from 99 mothers and their exclusively breastfed children at the age of 5 months. The mothers completed the Early Life Stress Questionnaire to assess childhood trauma. The questionnaire includes questions about the most traumatic events that they had experienced before the age of 12 years. Infant growth was evaluated based on the anthropometric measurements of weight, length, and head circumference. Also, to control for the size of maternal investment, the composition of breast milk samples taken at the time of infant anthropometric measurements was investigated. The children of mothers with higher early life stress tended to have higher weight and bigger head circumference. The association between infant anthropometrics and early maternal stress was not affected by breast milk composition, suggesting that the effect of maternal stress on infant growth was independent of the size of maternal investment. Our results demonstrate that early maternal trauma may affect the pace of growth in the offspring and, in consequence, lead to a faster life history strategy. This effect might be explained via changes in offspring epigenetics.
KW - maternal trauma
KW - early life trauma
KW - breastfed infant development
KW - POLS
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1285
SN - 0003-5548
SN - 2363-7099
VL - 77
IS - 5
SP - 359
EP - 374
PB - Schweizerbart science publishers
CY - Stuttgart
ER -
TY - JOUR
A1 - Canitz, Julia
A1 - Kirschbaum, Frank
A1 - Tiedemann, Ralph
T1 - Transcriptome-wide single nucleotide polymorphisms related to electric organ discharge differentiation among African weakly electric fish species
JF - PLoS one
N2 - African weakly electric fish of the mormyrid genus Campylomormyrus generate pulse-type electric organ discharges (EODs) for orientation and communication. Their pulse durations are species-specific and elongated EODs are a derived trait. So far, differential gene expression among tissue-specific transcriptomes across species with different pulses and point mutations in single ion channel genes indicate a relation of pulse duration and electrocyte geometry/excitability. However, a comprehensive assessment of expressed Single Nucleotide Polymorphisms (SNPs) throughout the entire transcriptome of African weakly electric fish, with the potential to identify further genes influencing EOD duration, is still lacking. This is of particular value, as discharge duration is likely based on multiple cellular mechanisms and various genes. Here we provide the first transcriptome-wide SNP analysis of African weakly electric fish species (genus Campylomormyrus) differing by EOD duration to identify candidate genes and cellular mechanisms potentially involved in the determination of an elongated discharge of C. tshokwe. Non-synonymous substitutions specific to C. tshokwe were found in 27 candidate genes with inferred positive selection among Campylomormyrus species. These candidate genes had mainly functions linked to transcriptional regulation, cell proliferation and cell differentiation. Further, by comparing gene annotations between C. compressirostris (ancestral short EOD) and C. tshokwe (derived elongated EOD), we identified 27 GO terms and 2 KEGG pathway categories for which C. tshokwe significantly more frequently exhibited a species-specific expressed substitution than C. compressirostris. The results indicate that transcriptional regulation as well cell proliferation and differentiation take part in the determination of elongated pulse durations in C. tshokwe. Those cellular processes are pivotal for tissue morphogenesis and might determine the shape of electric organs supporting the observed correlation between electrocyte geometry/tissue structure and discharge duration. The inferred expressed SNPs and their functional implications are a valuable resource for future investigations on EOD durations.
Y1 - 2020
U6 - https://doi.org/10.1371/journal.pone.0240812
SN - 1932-6203
VL - 15
IS - 10
PB - PLoS
CY - San Francisco, California, US
ER -
TY - JOUR
A1 - Weyrich, Alexandra
A1 - Yasar, Selma
A1 - Lenz, Dorina
A1 - Fickel, Jörns
T1 - Tissue-specific epigenetic inheritance after paternal heat exposure in male wild guinea pigs
JF - Mammalian genome
N2 - External temperature change has been shown to modify epigenetic patterns, such as DNA methylation, which regulates gene expression. DNA methylation is heritable, and as such provides a mechanism to convey environmental information to subsequent generations. Studies on epigenetic response to temperature increase are still scarce in wild mammals, even more so studies that compare tissue-specific epigenetic responses. Here, we aim to address differential epigenetic responses on a gene and gene pathway level in two organs, liver and testis. We chose these organs, because the liver is the main metabolic and thermoregulation organ, and epigenetic modifications in testis are potentially transmitted to the F2 generation. We focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to an ambient temperature increase of 10 degrees C, and investigated differential methylated regions of sons sired before and after the paternal exposure using Reduced Representation Bisulfite Sequencing. We detected both a highly tissue-specific epigenetic response, reflected in genes involved in organ-specific metabolic pathways, and a more general regulation of single genes epigenetically modified in both organs. We conclude that genomes are context-specifically differentially epigenetically regulated in response to temperature increase. These findings emphasize the epigenetic relevance in cell differentiation, which is essential for the specific function(s) of complex organs, and is represented in a diverse molecular regulation of genes and gene pathways. The results also emphasize the paternal contribution to adaptive processes.
KW - DNA methylation
KW - gene-expression
KW - CPG Islands
KW - stress
KW - hyperthermia
KW - testis
Y1 - 2020
U6 - https://doi.org/10.1007/s00335-020-09832-6
SN - 0938-8990
SN - 1432-1777
VL - 31
IS - 5-6
SP - 157
EP - 169
PB - Springer
CY - New York
ER -
TY - GEN
A1 - Weyrich, Alexandra
A1 - Yasar, Selma
A1 - Lenz, Dorina
A1 - Fickel, Jörns
T1 - Tissue-specific epigenetic inheritance after paternal heat exposure in male wild guinea pigs
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - External temperature change has been shown to modify epigenetic patterns, such as DNA methylation, which regulates gene expression. DNA methylation is heritable, and as such provides a mechanism to convey environmental information to subsequent generations. Studies on epigenetic response to temperature increase are still scarce in wild mammals, even more so studies that compare tissue-specific epigenetic responses. Here, we aim to address differential epigenetic responses on a gene and gene pathway level in two organs, liver and testis. We chose these organs, because the liver is the main metabolic and thermoregulation organ, and epigenetic modifications in testis are potentially transmitted to the F2 generation. We focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to an ambient temperature increase of 10 degrees C, and investigated differential methylated regions of sons sired before and after the paternal exposure using Reduced Representation Bisulfite Sequencing. We detected both a highly tissue-specific epigenetic response, reflected in genes involved in organ-specific metabolic pathways, and a more general regulation of single genes epigenetically modified in both organs. We conclude that genomes are context-specifically differentially epigenetically regulated in response to temperature increase. These findings emphasize the epigenetic relevance in cell differentiation, which is essential for the specific function(s) of complex organs, and is represented in a diverse molecular regulation of genes and gene pathways. The results also emphasize the paternal contribution to adaptive processes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1431
KW - DNA methylation
KW - gene-expression
KW - CPG Islands
KW - stress
KW - hyperthermia
KW - testis
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516525
SN - 1866-8372
IS - 5-6
ER -
TY - JOUR
A1 - Patterson, Jenelle A.
A1 - He, Hai
A1 - Folz, Jacob S.
A1 - Li, Qiang
A1 - Wilson, Mark A.
A1 - Fiehn, Oliver
A1 - Bruner, Steven D.
A1 - Bar-Even, Arren
A1 - Hanson, Andrew D.
T1 - Thioproline formation as a driver of formaldehyde toxicity in Escherichia coli
JF - Biochemical Journal
N2 - Formaldehyde (HCHO) is a reactive carbonyl compound that formylates and cross-links proteins, DNA, and small molecules. It is of specific concern as a toxic intermediate in the design of engineered pathways involving methanol oxidation or formate reduction. The interest in engineering these pathways is not, however, matched by engineering-relevant information on precisely why HCHO is toxic or on what damage-control mechanisms cells deploy to manage HCHO toxicity. The only well-defined mechanism for managing HCHO toxicity is formaldehyde dehydrogenase-mediated oxidation to formate, which is counterproductive if HCHO is a desired pathway intermediate. We therefore sought alternative HCHO damage-control mechanisms via comparative genomic analysis. This analysis associated homologs of the Escherichia coli pepP gene with HCHO-related one-carbon metabolism. Furthermore, deleting pepP increased the sensitivity of E. coli to supplied HCHO but not other carbonyl compounds. PepP is a proline aminopeptidase that cleaves peptides of the general formula X-Pro-Y, yielding X + Pro-Y. HCHO is known to react spontaneously with cysteine to form the close proline analog thioproline (thiazolidine-4-carboxylate), which is incorporated into proteins and hence into proteolytic peptides. We therefore hypothesized that certain thioproline-containing peptides are toxic and that PepP cleaves these aberrant peptides. Supporting this hypothesis, PepP cleaved the model peptide Ala-thioproline-Ala as efficiently as Ala-Pro-Ala in vitro and in vivo, and deleting pepP increased sensitivity to supplied thioproline. Our data thus (i) provide biochemical genetic evidence that thioproline formation contributes substantially to HCHO toxicity and (ii) make PepP a candidate damage-control enzyme for engineered pathways having HCHO as an intermediate.
KW - formaldehyde
KW - thiazolidine-4-carboxylic acid
KW - thioproline
KW - Xaa-Pro aminopeptidase
Y1 - 2020
U6 - https://doi.org/10.1042/BCJ20200198
SN - 1470-8728
SN - 0006-2936
VL - 477
IS - 9
SP - 1745
EP - 1757
PB - Portland Press
CY - London
ER -
TY - JOUR
A1 - Angelopoulos, Michael
A1 - Overduin, Pier Paul
A1 - Westermann, Sebastian
A1 - Tronicke, Jens
A1 - Strauss, Jens
A1 - Schirrmeister, Lutz
A1 - Biskaborn, Boris K.
A1 - Liebner, Susanne
A1 - Maksimov, Georgii
A1 - Grigoriev, Mikhail N.
A1 - Grosse, Guido
T1 - Thermokarst lake to lagoon transitions in Eastern Siberia
BT - do submerged taliks refreeze?
JF - Journal of geophysical research : Earth surface
N2 - As the Arctic coast erodes, it drains thermokarst lakes, transforming them into lagoons, and, eventually, integrates them into subsea permafrost. Lagoons represent the first stage of a thermokarst lake transition to a marine setting and possibly more saline and colder upper boundary conditions. In this research, borehole data, electrical resistivity surveying, and modeling of heat and salt diffusion were carried out at Polar Fox Lagoon on the Bykovsky Peninsula, Siberia. Polar Fox Lagoon is a seasonally isolated water body connected to Tiksi Bay through a channel, leading to hypersaline waters under the ice cover. The boreholes in the center of the lagoon revealed floating ice and a saline cryotic bed underlain by a saline cryotic talik, a thin ice-bearing permafrost layer, and unfrozen ground. The bathymetry showed that most of the lagoon had bedfast ice in spring. In bedfast ice areas, the electrical resistivity profiles suggested that an unfrozen saline layer was underlain by a thick layer of refrozen talik. The modeling showed that thermokarst lake taliks can refreeze when submerged in saltwater with mean annual bottom water temperatures below or slightly above 0 degrees C. This occurs, because the top-down chemical degradation of newly formed ice-bearing permafrost is slower than the refreezing of the talik. Hence, lagoons may precondition taliks with a layer of ice-bearing permafrost before encroachment by the sea, and this frozen layer may act as a cap on gas migration out of the underlying talik.
KW - thermokarst lake
KW - talik
KW - lagoon
KW - subsea permafrost
KW - salt diffusion
KW - Siberia
Y1 - 2020
U6 - https://doi.org/10.1029/2019JF005424
SN - 2169-9003
SN - 2169-9011
VL - 125
IS - 10
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Schneeberger, Karin
A1 - Röder, Gregory
A1 - Taborsky, Michael
T1 - The smell of hunger
BT - Norway rats provision social partners based on odour cues of need
JF - PLoS biology
N2 - When individuals exchange helpful acts reciprocally, increasing the benefit of the receiver can enhance its propensity to return a favour, as pay-offs are typically correlated in iterated interactions. Therefore, reciprocally cooperating animals should consider the relative benefit for the receiver when deciding to help a conspecific. Norway rats (Rattus norvegicus) exchange food reciprocally and thereby take into account both the cost of helping and the potential benefit to the receiver. By using a variant of the sequential iterated prisoner's dilemma paradigm, we show that rats may determine the need of another individual by olfactory cues alone. In an experimental food-exchange task, test subjects were provided with odour cues from hungry or satiated conspecifics located in a different room. Our results show that wild-type Norway rats provide help to a stooge quicker when they receive odour cues from a hungry rather than from a satiated conspecific. Using chemical analysis by gas chromatography-mass spectrometry (GC-MS), we identify seven volatile organic compounds that differ in their abundance between hungry and satiated rats. Combined, this "smell of hunger" can apparently serve as a reliable cue of need in reciprocal cooperation, which supports the hypothesis of honest signalling.
Y1 - 2020
U6 - https://doi.org/10.1371/journal.pbio.3000628
SN - 1544-9173
SN - 1545-7885
VL - 18
IS - 3
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Ehrlich, Elias
A1 - Kath, Nadja Jeanette
A1 - Gaedke, Ursula
T1 - The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton
JF - The ISME journal
N2 - Theory predicts that trade-offs, quantifying costs of functional trait adjustments, crucially affect community trait adaptation to altered environmental conditions, but empirical verification is scarce. We evaluated trait dynamics (antipredator defense, maximum growth rate, and phosphate affinity) of a lake phytoplankton community in a seasonally changing environment, using literature trait data and 21 years of species-resolved high-frequency biomass measurements. The trait data indicated a concave defense-growth trade-off, promoting fast-growing species with intermediate defense. With seasonally increasing grazing pressure, the community shifted toward higher defense levels at the cost of lower growth rates along the trade-off curve, while phosphate affinity explained some deviations from it. We discuss how low fitness differences of species, inferred from model simulations, in concert with stabilizing mechanisms, e.g., arising from further trait dimensions, may lead to the observed phytoplankton diversity. In conclusion, quantifying trade-offs is key for predictions of community trait adaptation and biodiversity under environmental change.
KW - coexistence
KW - community ecology
KW - diversity
KW - evolution
KW - fitness
KW - functional traits
KW - lake
KW - maintenance
KW - mechanisms
KW - plankton
Y1 - 2020
U6 - https://doi.org/10.1038/s41396-020-0619-1
SN - 1751-7362
SN - 1751-7370
VL - 14
IS - 6
SP - 1451
EP - 1462
PB - Nature Publishing Group
CY - London
ER -
TY - GEN
A1 - Ehrlich, Elias
A1 - Kath, Nadja Jeanette
A1 - Gaedke, Ursula
T1 - The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Theory predicts that trade-offs, quantifying costs of functional trait adjustments, crucially affect community trait adaptation to altered environmental conditions, but empirical verification is scarce. We evaluated trait dynamics (antipredator defense, maximum growth rate, and phosphate affinity) of a lake phytoplankton community in a seasonally changing environment, using literature trait data and 21 years of species-resolved high-frequency biomass measurements. The trait data indicated a concave defense-growth trade-off, promoting fast-growing species with intermediate defense. With seasonally increasing grazing pressure, the community shifted toward higher defense levels at the cost of lower growth rates along the trade-off curve, while phosphate affinity explained some deviations from it. We discuss how low fitness differences of species, inferred from model simulations, in concert with stabilizing mechanisms, e.g., arising from further trait dimensions, may lead to the observed phytoplankton diversity. In conclusion, quantifying trade-offs is key for predictions of community trait adaptation and biodiversity under environmental change.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1390
KW - functional traits
KW - community ecology
KW - evolution
KW - lake
KW - mechanisms
KW - diversity
KW - plankton
KW - fitness
KW - maintenance
KW - coexistence
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513956
SN - 1866-8372
IS - 6
ER -
TY - JOUR
A1 - Schneeberger, Karin
A1 - Taborsky, Michael
T1 - The role of sensory ecology and cognition in social decisions
BT - costs of acquiring information matter
JF - Functional ecology : an official journal of the British Ecological Society
N2 - 1. We generally assume that animals should maximize information acquisition about their environment to make prudent decisions. But this is a naive assumption, as gaining information typically involves costs.
2. This is especially so in the social context, where interests between interacting partners usually diverge. The arms race involved in mutual assessment is characterized by the attempt to obtain revealing information from a partner while providing only as much information by oneself as is conducive to one's own intentions.
3. If obtaining information occasions costs in terms of time, energy and risk, animals should be selected to base their decisions on a cost-benefit ratio that takes account of the trade-off between the risk of making wrong choices and the costs involved in information acquisition, processing and use.
4. In addition, there may be physiological and/or environmental constraints limiting the ability to obtaining, processing and utilizing reliable information.
5. Here, we discuss recent empirical evidence for the proposition that social decisions are to an important extent based on the costs that result from acquiring, processing, evaluating and storing information. Using examples from different taxa and ecological contexts, we aim at drawing attention to the often neglected costs of information recipience, with emphasis on the potential role of sensory ecology and cognition in social decisions.
KW - behaviour
KW - constrains
KW - costs
KW - decisions
KW - signals
KW - sociality
KW - trade-offs
Y1 - 2020
U6 - https://doi.org/10.1111/1365-2435.13488
SN - 0269-8463
SN - 1365-2435
VL - 34
IS - 2
SP - 302
EP - 309
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Mendel, Ralf R.
A1 - Hercher, Thomas W.
A1 - Zupok, Arkadiusz
A1 - Hasnat, Muhammad Abrar
A1 - Leimkühler, Silke
T1 - The requirement of inorganic Fe-S clusters for the biosynthesis of the organometallic molybdenum cofactor
JF - Inorganics : open access journal
N2 - Iron-sulfur (Fe-S) clusters are essential protein cofactors. In enzymes, they are present either in the rhombic [2Fe-2S] or the cubic [4Fe-4S] form, where they are involved in catalysis and electron transfer and in the biosynthesis of metal-containing prosthetic groups like the molybdenum cofactor (Moco). Here, we give an overview of the assembly of Fe-S clusters in bacteria and humans and present their connection to the Moco biosynthesis pathway. In all organisms, Fe-S cluster assembly starts with the abstraction of sulfur froml-cysteine and its transfer to a scaffold protein. After formation, Fe-S clusters are transferred to carrier proteins that insert them into recipient apo-proteins. In eukaryotes like humans and plants, Fe-S cluster assembly takes place both in mitochondria and in the cytosol. Both Moco biosynthesis and Fe-S cluster assembly are highly conserved among all kingdoms of life. Moco is a tricyclic pterin compound with molybdenum coordinated through its unique dithiolene group. Moco biosynthesis begins in the mitochondria in a Fe-S cluster dependent step involving radical/S-adenosylmethionine (SAM) chemistry. An intermediate is transferred to the cytosol where the dithiolene group is formed, to which molybdenum is finally added. Further connections between Fe-S cluster assembly and Moco biosynthesis are discussed in detail.
KW - Moco biosynthesis
KW - Fe-S cluster assembly
KW - l-cysteine desulfurase
KW - ISC
KW - SUF
KW - NIF
KW - iron
KW - molybdenum
KW - sulfur
Y1 - 2020
U6 - https://doi.org/10.3390/inorganics8070043
SN - 2304-6740
VL - 8
IS - 7
PB - MDPI
CY - Basel
ER -
TY - GEN
A1 - Jannasch, Franziska
A1 - Nickel, Daniela
A1 - Schulze, Matthias B.
T1 - The reliability and relative validity of predefined dietary patterns were higher than that of exploratory dietary patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam population
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The aim of this study was to assess the ability of the FFQ to describe reliable and valid dietary pattern (DP) scores. In a total of 134 participants of the European Prospective Investigation into Cancer and Nutrition-Potsdam study aged 35-67 years, the FFQ was applied twice (baseline and after 1 year) to assess its reliability. Between November 1995 and March 1997, twelve 24-h dietary recalls (24HDR) as reference instrument were applied to assess the validity of the FFQ. Exploratory DP were derived by principal component analyses. Investigated predefined DP were the Alternative Healthy Eating Index (AHEI) and two Mediterranean diet indices. From dietary data of each FFQ, two exploratory DP were retained, but differed in highly loading food groups, resulting in moderate correlations (r 0 center dot 45-0 center dot 58). The predefined indices showed higher correlations between the FFQ (r(AHEI) 0 center dot 62, r(Mediterranean Diet Pyramid Index (MedPyr)) 0 center dot 62 and r(traditional Mediterranean Diet Score (tMDS)) 0 center dot 51). From 24HDR dietary data, one exploratory DP retained differed in composition to the first FFQ-based DP, but showed similarities to the second DP, reflected by a good correlation (r 0 center dot 70). The predefined DP correlated moderately (r 0 center dot 40-0 center dot 60). To conclude, long-term analyses on exploratory DP should be interpreted with caution, due to only moderate reliability. The validity differed extensively for the two exploratory DP. The investigated predefined DP showed a better reliability and a moderate validity, comparable to other studies. Within the two Mediterranean diet indices, the MedPyr performed better than the tMDs in this middle-aged, semi-urban German study population.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1349
KW - dietary patterns
KW - reliability
KW - validity
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-550030
SN - 1866-8372
VL - 125
IS - 11
ER -
TY - THES
A1 - Hoelscher, Matthijs Pieter
T1 - The production of antimicrobial polypeptides in chloroplasts
N2 - Plants are an attractive platform for the production of medicinal compounds because of their potential to generate large amounts of biomass cheaply. The use of chloroplast transformation is an attractive way to achieve the recombinant production of proteins in plants, because of the chloroplasts’ high capacity to produce foreign proteins in comparison to nuclear transformed plants. In this thesis, the production of two different types of antimicrobial polypeptides in chloroplasts is explored.
The first example is the production of the potent HIV entry inhibitor griffithsin. Griffithsin has the potential to prevent HIV infections by blocking the entry of the virus into human cells. Here the use of transplastomic plants as an inexpensive production method for griffithsin was explored. Transplastomic plants grew healthily and were able to accumulate griffithsin to up to 5% of the total soluble protein. Griffithsin could easily be purified from tobacco leaf tissue and had a similarly high neutralization activity as griffithsin recombinantly produced in bacteria. Griffithsin could be purified from dried tobacco leaves, demonstrating that dried leaves could be used as a storable starting material for griffithsin purification, circumventing the need for immediate purification after harvest.
The second example is the production of antimicrobial peptides (AMPs) that have the capacity to kill bacteria and are an attractive alternative to currently used antibiotics that are increasingly becoming ineffective. The production of antimicrobial peptides was considerably more challenging than the production of griffithsin. Small AMPs are prone to degradation in plastids. This problem was overcome by fusing AMPs to generate larger polypeptides. In one approach, AMPs were fused to each other to increase size and combine the mode of action of multiple AMPs. This improved the accumulation of AMPs but also resulted in impaired plant growth. This was solved by the use of two different inducible systems, which could largely restore plant growth. Fusions of multiple AMPs were insoluble and could not be purified.
In addition to fusing AMPs to each other, the fusion of AMPs to small ubiquitin-like modifier (SUMO), was tested as an approach to improve the accumulation, facilitate purification, and reduce the toxicity of AMPs to chloroplasts. Fusion of AMPs to SUMO indeed increased accumulation while reducing the toxicity to the plants. SUMO fusions produced inside chloroplasts could be purified, and SUMO could be efficiently cleaved off with the SUMO protease. Such fusions therefore provide a promising strategy for the production of AMPs and other small polypeptides inside chloroplasts.
KW - plastid transformation
KW - Nicotiana tabacum
KW - HIV
KW - AIDS
KW - antiviral agent
KW - micorbicide
KW - Griffithsin
KW - chloroplast
KW - antimicrobial peptide
KW - AMP
KW - recombinant production
KW - transgenic
KW - SUMO
KW - inducible expression
KW - anti bacterial
KW - protein fusion
KW - polypeptide
KW - peptide
KW - plant
KW - molecular farming
Y1 - 2020
ER -
TY - JOUR
A1 - Rybak, Alexander
A1 - Bents, Dominik
A1 - Krüger, Johanna
A1 - Groth, Detlef
T1 - The end of the secular trend in Norway
BT - spatial trends in body height of Norwegian conscripts in the 19th, 20th and 21st century
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie
N2 - Aim: We aimed to examine the distribution and secular changes of conscript body height in the geographic network of Norway since 1878 and to study its association with the degree of urbanization, and population density. Material and methods: Data on body height of Norwegian military conscripts were provided by the Statistics Norway Department (SSB). The sample comprised eight cohorts with the following measurement years: 1st 1877, 1878 and 1880, 2nd 18951897, 3rd 1915-1917, 4th 1935-1937, 5th 1955-1957, 6th 1975-1977, 7th 1995-1997, and 8th 2009-2011. For determining neighborhood correlations, a network was created consisting of neighboring counties, sharing a common border. Results: Average body height of Norwegian men increased by 10.9 cm between 1878 and 2010, but this trend was heterogeneous. Some counties increased by more than 1 cm per decade (Finmark) others by only 7 mm per decade (Sor-Trondelag). Urban counties and counties with higher population density showed stronger height trends than rural counties. The largest spread in body height between the various counties was observed in 1936 when for the first time people living in the more urban counties got taller than rural people. The height advantage of urban counties however, disappeared after 1996. At this time, also the secular trend in height had come to a halt. The secular trend in height had become obvious after the dissolution of the union between Norway and Sweden in 1905 and World War I, and was strongest between 1936 and 1956. During this period maximum between-county heterogeneity in height existed with body height differences of more than 6 cm between the tallest and the shortest county. The end of this period was characterized by social democratic reforms that flattened the income distribution, eliminated poverty, and ensured social services after World War II. Conclusion: The temporal coincidence between the trends in height, the degree of urbanization and the onset of the political transition of Norway from a Swedish province into an independent democratic wealthy modern European state after World War I and particularly after World War II, and the abatement of this trend after this period of transition had stabilized, suggest social and political components interfering with the regulation of physical growth in humans.
KW - male body height
KW - degree of urbanization
KW - population density
KW - Norway
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1254
SN - 0003-5548
VL - 77
IS - 5
SP - 415
EP - 421
PB - Schweizerbart
CY - Stuttgart
ER -
TY - JOUR
A1 - Apriyanto, Ardha
A1 - Tambunan, Van Basten
T1 - The complete mitochondrial genome of oil palm pollinating weevil, Elaeidobius kamerunicus Faust
BT - (Coleoptera : Curculionidae)
JF - Mitochondrial DNA: Part B
N2 - Elaeidobius kamerunicusis the most important insect pollinator in oil palm plantations. In this study, the mitochondrial genome (mitogenome) ofE. kamerunicus(17.729 bp), a member of the Curculionidae family, will be reported. The mitogenome consisted of 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and a putative control region (CR). Phylogenetic analysis based on 13 protein-coding genes (PCGs) using maximum Likelihood (ML) methods indicated thatE. kamerunicusbelongs to the Curculionidae family. This mitochondrial genome provides essential information for understanding genetic populations, phylogenetics, molecular evolution, and other biological applications in this species.
KW - Mitogenome
KW - oil palm
KW - pollinator
KW - phylogeny
KW - weevil
Y1 - 2020
U6 - https://doi.org/10.1080/23802359.2020.1823899
SN - 2380-2359
VL - 5
IS - 3
SP - 3450
EP - 3452
PB - Routledge, Taylor & Francis Group
CY - Abingdon
ER -
TY - JOUR
A1 - Premier, Joseph
A1 - Fickel, Jörns
A1 - Heurich, Marco
A1 - Kramer-Schadt, Stephanie
T1 - The boon and bane of boldness
BT - movement syndrome as saviour and sink for population genetic diversity
JF - Movement Ecology
N2 - Background:
Many felid species are of high conservation concern, and with increasing human disturbance the situation is worsening. Small isolated populations are at risk of genetic impoverishment decreasing within-species biodiversity. Movement is known to be a key behavioural trait that shapes both demographic and genetic dynamics and affects population survival. However, we have limited knowledge on how different manifestations of movement behaviour translate to population processes. In this study, we aimed to 1) understand the potential effects of movement behaviour on the genetic diversity of small felid populations in heterogeneous landscapes, while 2) presenting a simulation tool that can help inform conservation practitioners following, or considering, population management actions targeting the risk of genetic impoverishment.
Methods:
We developed a spatially explicit individual-based population model including neutral genetic markers for felids and applied this to the example of Eurasian lynx. Using a neutral landscape approach, we simulated reintroductions into a three-patch system, comprising two breeding patches separated by a larger patch of differing landscape heterogeneity, and tested for the effects of various behavioural movement syndromes and founder population sizes. We explored a range of movement syndromes by simulating populations with various movement model parametrisations that range from 'shy' to 'bold' movement behaviour.
Results:
We find that movement syndromes can lead to a higher loss of genetic diversity and an increase in between population genetic structure for both "bold" and "shy" movement behaviours, depending on landscape conditions, with larger decreases in genetic diversity and larger increases in genetic differentiation associated with bold movement syndromes, where the first colonisers quickly reproduce and subsequently dominate the gene pool. In addition, we underline the fact that a larger founder population can offset the genetic losses associated with subpopulation isolation and gene pool dominance. Conclusions We identified a movement syndrome trade-off for population genetic variation, whereby bold-explorers could be saviours - by connecting populations and promoting panmixia, or sinks - by increasing genetic losses via a 'founder takes all' effect, whereas shy-stayers maintain a more gradual genetic drift due to their more cautious behaviour. Simulations should incorporate movement behaviour to provide better projections of long-term population viability and within-species biodiversity, which includes genetic diversity. Simulations incorporating demographics and genetics have great potential for informing conservation management actions, such as population reintroductions or reinforcements. Here, we present such a simulation tool for solitary felids.
KW - Lynx lynx
KW - neutral landscape models
KW - eurasian lynx
KW - natal dispersal
KW - home range
KW - fragmented landscapes
KW - behavioral syndromes
KW - habitat loss
KW - personality
KW - mortality
Y1 - 2020
U6 - https://doi.org/10.1186/s40462-020-00204-y
SN - 2051-3933
VL - 8
IS - 1
SP - 1
EP - 17
PB - BioMed Central
CY - London
ER -
TY - JOUR
A1 - Leimkühler, Silke
T1 - The biosynthesis of the molybdenum cofactors in Escherichia coli
JF - Environmental microbiology
N2 - The biosynthesis of the molybdenum cofactor (Moco) is highly conserved among all kingdoms of life. In all molybdoenzymes containing Moco, the molybdenum atom is coordinated to a dithiolene group present in the pterin-based 6-alkyl side chain of molybdopterin (MPT). In general, the biosynthesis of Moco can be divided into four steps in in bacteria: (i) the starting point is the formation of the cyclic pyranopterin monophosphate (cPMP) from 5 '-GTP, (ii) in the second step the two sulfur atoms are inserted into cPMP leading to the formation of MPT, (iii) in the third step the molybdenum atom is inserted into MPT to form Moco and (iv) in the fourth step bis-Mo-MPT is formed and an additional modification of Moco is possible with the attachment of a nucleotide (CMP or GMP) to the phosphate group of MPT, forming the dinucleotide variants of Moco. This review presents an update on the well-characterized Moco biosynthesis in the model organism Escherichia coli including novel discoveries from the recent years.
KW - periplasmic nitrate reductase
KW - biotin sulfoxide reductase
KW - in-vitro-synthesis
KW - n-oxide reductase
KW - crystal-structure
KW - molybdopterin synthase
KW - formate dehydrogenase
KW - rhodobacter-capsulatus
KW - xanthine dehydrogenase
KW - converting factor
Y1 - 2020
U6 - https://doi.org/10.1111/1462-2920.15003
SN - 1462-2912
SN - 1462-2920
VL - 22
IS - 6
SP - 2007
EP - 2026
PB - Wiley
CY - Hoboken
ER -
TY - GEN
A1 - Leimkühler, Silke
T1 - The biosynthesis of the molybdenum cofactors in Escherichia coli
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The biosynthesis of the molybdenum cofactor (Moco) is highly conserved among all kingdoms of life. In all molybdoenzymes containing Moco, the molybdenum atom is coordinated to a dithiolene group present in the pterin-based 6-alkyl side chain of molybdopterin (MPT). In general, the biosynthesis of Moco can be divided into four steps in in bacteria: (i) the starting point is the formation of the cyclic pyranopterin monophosphate (cPMP) from 5 '-GTP, (ii) in the second step the two sulfur atoms are inserted into cPMP leading to the formation of MPT, (iii) in the third step the molybdenum atom is inserted into MPT to form Moco and (iv) in the fourth step bis-Mo-MPT is formed and an additional modification of Moco is possible with the attachment of a nucleotide (CMP or GMP) to the phosphate group of MPT, forming the dinucleotide variants of Moco. This review presents an update on the well-characterized Moco biosynthesis in the model organism Escherichia coli including novel discoveries from the recent years.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1433
KW - periplasmic nitrate reductase
KW - biotin sulfoxide reductase
KW - in-vitro-synthesis
KW - n-oxide reductase
KW - crystal-structure
KW - molybdopterin synthase
KW - formate dehydrogenase
KW - rhodobacter-capsulatus
KW - xanthine dehydrogenase
KW - converting factor
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516559
SN - 1866-8372
IS - 6
ER -
TY - JOUR
A1 - Schellenberg, Johannes
A1 - Reichert, Jessica
A1 - Hardt, Martin
A1 - Klingelhöfer, Ines
A1 - Morlock, Gertrud
A1 - Schubert, Patrick
A1 - Bižić, Mina
A1 - Grossart, Hans-Peter
A1 - Kämpfer, Peter
A1 - Wilke, Thomas
A1 - Glaeser, Stefanie P.
T1 - The bacterial microbiome of the long-term aquarium cultured high-microbial abundance sponge Haliclona cnidata
BT - sustained bioactivity despite community shifts under detrimental conditions
JF - Frontiers in Marine Science
N2 - Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that the long-term aquarium cultured sponge H. cnidata is tightly associated with a typical sponge bacterial microbiota and (2) that the symbiotic Bacteria sustain bioactivity under harmful environmental conditions to facilitate holobiont survival by preventing pathogen invasion. Microscopic and phylogenetic analyses of the bacterial microbiota revealed that H. cnidata represents a high microbial abundance (HMA) sponge with a temporally stable bacterial community that significantly shifts with changing aquarium conditions. A 4-week incubation experiment was performed in small closed aquarium systems with antibiotic and/or light exclusion treatments to reduce the total bacterial and photosynthetically active sponge-associated microbiota to a treatment-specific resilient community. While the holobiont was severely affected by the experimental treatment (i.e., bleaching of the sponge, reduced bacterial abundance, shifted bacterial community composition), the biological defense and bacterial community interactions (i.e., quorum sensing activity) remained intact. 16S rRNA gene amplicon sequencing revealed a resilient community of 105 bacterial taxa, which remained in the treated sponges. These 105 taxa accounted for a relative abundance of 72-83% of the bacterial sponge microbiota of non-treated sponge fragments that have been cultured under the same conditions. We conclude that a sponge-specific resilient community stays biologically active under harmful environmental conditions, facilitating the resilience of the holobiont. In H. cnidata, bacteria are located in bacteriocytes, which may have contributed to the observed phenomenon.
KW - HMA sponge
KW - bacterial symbionts
KW - holobiont
KW - antimicrobial defense
KW - quorum sensing
KW - bacteriocytes
Y1 - 2020
U6 - https://doi.org/10.3389/fmars.2020.00266
SN - 2296-7745
VL - 7
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Rillig, Matthias C.
A1 - Bielcik, Milos
A1 - Chaudhary, Veer Bala
A1 - Grünfeld, Leonie
A1 - Maass, Stefanie
A1 - Mansour, India
A1 - Ryo, Masahiro
A1 - Veresoglou, Stavros D.
T1 - Ten simple rules for increased lab resilience
JF - PLoS Computational Biology : a new community journal
N2 - When running a lab we do not think about calamities, since they are rare events for which we cannot plan while we are busy with the day-to-day management and intellectual challenges of a research lab. No lab team can be prepared for something like a pandemic such as COVID-19, which has led to shuttered labs around the globe. But many other types of crises can also arise that labs may have to weather during their lifetime. What can researchers do to make a lab more resilient in the face of such exterior forces? What systems or behaviors could we adjust in 'normal' times that promote lab success, and increase the chances that the lab will stay on its trajectory? We offer 10 rules, based on our current experiences as a lab group adapting to crisis.
Y1 - 2020
U6 - https://doi.org/10.1371/journal.pcbi.1008313
SN - 1553-734X
SN - 1553-7358
VL - 16
IS - 11
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Paraskevopoulou, Sofia
A1 - Dennis, Alice B.
A1 - Weithoff, Guntram
A1 - Tiedemann, Ralph
T1 - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers
JF - Scientific Reports
N2 - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming.
KW - Ecology
KW - Evolution
KW - Oyster Crassostrea-gigas
KW - cryptic species complex
KW - pacific oyster
KW - thermal-stress
KW - genetic differentiation
KW - expression patterns
KW - molecular phylogeny
KW - shock proteins
KW - evolutionary
KW - hsp70
Y1 - 2020
U6 - https://doi.org/10.1038/s41598-020-70173-0
SN - 2045-2322
VL - 10
PB - Macmillan Publishers Limited, part of Springer Nature
CY - London
ER -
TY - GEN
A1 - Paraskevopoulou, Sofia
A1 - Dennis, Alice B.
A1 - Weithoff, Guntram
A1 - Tiedemann, Ralph
T1 - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers
T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2 - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1012
KW - Ecology
KW - Evolution
KW - Oyster Crassostrea-gigas
KW - cryptic species complex
KW - pacific oyster
KW - thermal-stress
KW - genetic differentiation
KW - expression patterns
KW - molecular phylogeny
KW - shock proteins
KW - evolutionary
KW - hsp70
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-482280
SN - 1866-8372
IS - 1012
ER -
TY - JOUR
A1 - Masigol, Hossein
A1 - Khodaparast, Seyed Akbar
A1 - Mostowfizadeh-Ghalamfarsa, Reza
A1 - Rojas-Jimenez, Keilor
A1 - Woodhouse, Jason Nicholas
A1 - Neubauer, Darshan
A1 - Grossart, Hans-Peter
T1 - Taxonomical and functional diversity of Saprolegniales in Anzali lagoon, Iran
JF - Aquatic Ecology
N2 - Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems.
KW - Achlya
KW - Saprolegnia
KW - aquatic ecosystems
KW - carbon cycling
KW - polymer degradation
KW - Saprolegniaceae
KW - Achlyaceae
Y1 - 2020
U6 - https://doi.org/10.1007/s10452-019-09745-w
SN - 1573-5125
SN - 1386-2588
VL - 54
IS - 1
SP - 323
EP - 336
PB - Springer Science
CY - Dordrecht
ER -
TY - GEN
A1 - Masigol, Hossein
A1 - Khodaparast, Seyed Akbar
A1 - Mostowfizadeh-Ghalamfarsa, Reza
A1 - Rojas-Jimenez, Keilor
A1 - Woodhouse, Jason Nicholas
A1 - Neubauer, Darshan
A1 - Grossart, Hans-Peter
T1 - Taxonomical and functional diversity of Saprolegniales in Anzali lagoon, Iran
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1395
KW - Achlya
KW - Saprolegnia
KW - aquatic ecosystems
KW - carbon cycling
KW - polymer degradation
KW - Saprolegniaceae
KW - Achlyaceae
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515820
SN - 1866-8372
IS - 1
ER -
TY - THES
A1 - Kožul, Danijela
T1 - Systematic identification of loci determining chloroplast and nuclear genome incompatibility in the evening primrose (Oenothera)
Y1 - 2020
ER -
TY - THES
A1 - Kubis, Armin
T1 - Synthetic carbon neutral photorespiration bypasses
BT - implementation and testing in Escherichia coli
N2 - With populations growing worldwide and climate change threatening food production there is an urgent need to find ways to ensure food security. Increasing carbon fixation rate in plants is a promising approach to boost crop yields. The carbon-fixing enzyme Rubisco catalyzes, beside the carboxylation reaction, also an oxygenation reaction that generates glycolate-2P, which needs to be recycled via a metabolic route termed photorespiration. Photorespiration dissipates energy and most importantly releases previously fixed CO2, thus significantly lowering carbon fixation rate and yield. Engineering plants to omit photorespiratory CO2 release is the goal of the FutureAgriculture consortium and this thesis is part of this collaboration. The consortium aims to establish alternative glycolate-2P recycling routes that do not release CO2. Ultimately, they are expected to increase carbon fixation rates and crop yields. Natural and novel reactions, which require enzyme engineering, were considered in the pathway design process. Here I describe the engineering of two pathways, the arabinose-5P and the erythrulose shunt. They were designed to recycle glycolate-2P via glycolaldehyde into a sugar phosphate and thereby reassimilate glycolate-2P to the Calvin cycle. I used Escherichia coli gene deletion strains to validate and characterize the activity of both synthetic shunts. The strains’ auxotrophies can be alleviated by the activity of the synthetic route, thus providing a direct way to select for pathway activity. I introduced all pathway components to these dedicated selection strains and discovered inhibitions, limitations and metabolic cross talk interfering with pathway activity. After resolving these issues, I was able to show the in vivo activity of all pathway components and combine them into functional modules.. Specifically, I demonstrate the activity of a new-to-nature module of glycolate reduction to glycolaldehyde. Also, I successfully show a new glycolaldehyde assimilation route via arabinose-5P to ribulose-5P. In addition, all necessary enzymes for glycolaldehyde assimilation via L-erythrulose were shown to be active and an L-threitol assimilation route via L-erythrulose was established in E. coli. On their own, these findings demonstrate the power of using an easily engineerable microbe to test novel pathways; combined, they will form the basis for implementing photorespiration bypasses in plants.
KW - Synthetic Biology
KW - Photorespiration
KW - Metabolic Engineering
KW - Escherichia coli
Y1 - 2020
ER -
TY - JOUR
A1 - Razaghi-Moghadam, Zahra
A1 - Nikoloski, Zoran
T1 - Supervised learning of gene-regulatory networks based on graph distance profiles of transcriptomics data
JF - npj Systems biology and applications
N2 - Characterisation of gene-regulatory network (GRN) interactions provides a stepping stone to understanding how genes affect cellular phenotypes. Yet, despite advances in profiling technologies, GRN reconstruction from gene expression data remains a pressing problem in systems biology. Here, we devise a supervised learning approach, GRADIS, which utilises support vector machine to reconstruct GRNs based on distance profiles obtained from a graph representation of transcriptomics data. By employing the data fromEscherichia coliandSaccharomyces cerevisiaeas well as synthetic networks from the DREAM4 and five network inference challenges, we demonstrate that our GRADIS approach outperforms the state-of-the-art supervised and unsupervided approaches. This holds when predictions about target genes for individual transcription factors as well as for the entire network are considered. We employ experimentally verified GRNs fromE. coliandS. cerevisiaeto validate the predictions and obtain further insights in the performance of the proposed approach. Our GRADIS approach offers the possibility for usage of other network-based representations of large-scale data, and can be readily extended to help the characterisation of other cellular networks, including protein-protein and protein-metabolite interactions.
Y1 - 2020
U6 - https://doi.org/10.1038/s41540-020-0140-1
SN - 2056-7189
VL - 6
IS - 1
PB - Nature Publ. Group
CY - London
ER -
TY - GEN
A1 - Razaghi-Moghadam, Zahra
A1 - Nikoloski, Zoran
T1 - Supervised learning of gene regulatory networks
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Identifying the entirety of gene regulatory interactions in a biological system offers the possibility to determine the key molecular factors that affect important traits on the level of cells, tissues, and whole organisms. Despite the development of experimental approaches and technologies for identification of direct binding of transcription factors (TFs) to promoter regions of downstream target genes, computational approaches that utilize large compendia of transcriptomics data are still the predominant methods used to predict direct downstream targets of TFs, and thus reconstruct genome-wide gene-regulatory networks (GRNs). These approaches can broadly be categorized into unsupervised and supervised, based on whether data about known, experimentally verified gene-regulatory interactions are used in the process of reconstructing the underlying GRN. Here, we first describe the generic steps of supervised approaches for GRN reconstruction, since they have been recently shown to result in improved accuracy of the resulting networks? We also illustrate how they can be used with data from model organisms to obtain more accurate prediction of gene regulatory interactions.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1185
KW - gene expression profiles
KW - gene regulatory networks
KW - supervised learning
KW - support vector machine
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516561
SN - 1866-8372
ER -
TY - JOUR
A1 - Huu, Cuong Nguyen
A1 - Keller, Barbara
A1 - Conti, Elena
A1 - Kappel, Christian
A1 - Lenhard, Michael
T1 - Supergene evolution via stepwise duplications and neofunctionalization of a floral-organ identity gene
JF - Proceedings of the National Academy of Sciences of the United States of America (PNAS)
N2 - Heterostyly represents a fascinating adaptation to promote outbreeding in plants that evolved multiple times independently. While L-morph individuals form flowers with long styles, short anthers, and small pollen grains, S-morph individuals have flowers with short styles, long anthers, and large pollen grains. The difference between the morphs is controlled by an S-locus "supergene" consisting of several distinct genes that determine different traits of the syndrome and are held together, because recombination between them is suppressed. In Primula, the S locus is a roughly 300-kb hemizygous region containing five predicted genes. However, with one exception, their roles remain unclear, as does the evolutionary buildup of the S locus. Here we demonstrate that the MADS-box GLOBOSA2 (GLO2) gene at the S locus determines anther position. In Primula forbesii S-morph plants, GLO2 promotes growth by cell expansion in the fused tube of petals and stamen filaments beneath the anther insertion point; by contrast, neither pollen size nor male incompatibility is affected by GLO2 activity. The paralogue GLO1, from which GLO2 arose by duplication, has maintained the ancestral B-class function in specifying petal and stamen identity, indicating that GLO2 underwent neofunctionalization, likely at the level of the encoded protein. Genetic mapping and phylogenetic analysis indicate that the duplications giving rise to the style-length-determining gene CYP734A50 and to GLO2 occurred sequentially, with the CYP734A50 duplication likely the first. Together these results provide the most detailed insight into the assembly of a plant supergene yet and have important implications for the evolution of heterostyly.
KW - heterostyly
KW - Primula
KW - supergene
KW - gene duplication
KW - neofunctionalization
Y1 - 2020
U6 - https://doi.org/10.1073/pnas.2006296117
SN - 0027-8424
VL - 117
IS - 37
SP - 23148
EP - 23157
PB - National Academy of Sciences
CY - Washington
ER -
TY - THES
A1 - Moratti, Fabio Giulio
T1 - Structural analysis of DYW proteins and identification of the mitochondrial DNA-binding proteome of Arabidopsis thaliana
Y1 - 2020
ER -
TY - THES
A1 - Naake, Thomas
T1 - Strategies to investigate the natural variation of plant specialized metabolism
Y1 - 2020
ER -
TY - JOUR
A1 - Hermanussen, Michael
A1 - Groth, Detlef
A1 - Scheffler, Christiane
T1 - Statistical approaches to developmental and growth data of children and adolescents
BT - an editorial to student research conducted during the 3rd international student summer school, July 2019, Potsdam and Gülpe, Germany
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie
KW - human growth
KW - bone accumulation
KW - environmental effects
KW - migration
KW - socioeconomic status
KW - parental education
KW - nutrition
KW - statistical tools
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1302
SN - 0003-5548
SN - 2363-7099
VL - 77
IS - 5
SP - 355
EP - 357
PB - Schweizerbart
CY - Stuttgart
ER -
TY - JOUR
A1 - Brust, Henrike
A1 - Orzechowski, Slawomir
A1 - Fettke, Jörg
T1 - Starch and Glycogen Analyses
BT - Methods and Techniques
JF - Biomolecules
N2 - For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included
KW - starch
KW - glycogen
KW - analytics
Y1 - 2020
U6 - https://doi.org/10.3390/biom10071020
SN - 2218-273X
VL - 10
IS - 7
PB - MDPI
CY - Basel
ER -
TY - GEN
A1 - Brust, Henrike
A1 - Orzechowski, Slawomir
A1 - Fettke, Jörg
T1 - Starch and Glycogen Analyses
BT - Methods and Techniques
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1004
KW - starch
KW - glycogen
KW - analytics
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-478054
SN - 1866-8372
IS - 1004
ER -
TY - JOUR
A1 - Crawford, Tim
A1 - Karamat, Fazeelat
A1 - Lehotai, Nóra
A1 - Rentoft, Matilda
A1 - Blomberg, Jeanette
A1 - Strand, Åsa
A1 - Björklund, Stefan
T1 - Specific functions for mediator complex subunits from different modules in the transcriptional response of arabidopsis thaliana to abiotic stress
JF - Scientific reports
N2 - Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization.
KW - regulate gene expression
KW - signal transduction
KW - circadian clock
KW - plant Mediator
KW - salicylic-acid
KW - activation
KW - jasmonate
KW - network
KW - defense
KW - MED16
Y1 - 2020
U6 - https://doi.org/10.1038/s41598-020-61758-w
SN - 2045-2322
VL - 10
IS - 1
SP - 1
EP - 18
PB - Macmillan Publishers Limited, part of Springer Nature
CY - London
ER -
TY - GEN
A1 - Crawford, Tim
A1 - Karamat, Fazeelat
A1 - Lehotai, Nóra
A1 - Rentoft, Matilda
A1 - Blomberg, Jeanette
A1 - Strand, Åsa
A1 - Björklund, Stefan
T1 - Specific functions for mediator complex subunits from different modules in the transcriptional response of arabidopsis thaliana to abiotic stress
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1399
KW - regulate gene expression
KW - signal transduction
KW - circadian clock
KW - plant Mediator
KW - salicylic-acid
KW - activation
KW - jasmonate
KW - network
KW - defense
KW - MED16
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513666
SN - 1866-8372
IS - 1
ER -
TY - JOUR
A1 - König, Christian
A1 - Weigelt, Patrick
A1 - Taylor, Amanda
A1 - Stein, Anke
A1 - Dawson, Wayne
A1 - Essl, Franz
A1 - Pergl, Jan
A1 - Pyšek, Petr
A1 - Kleunen, Mark van
A1 - Winter, Marten
A1 - Chatelain, Cyrille
A1 - Wieringa, Jan J.
A1 - Krestov, Pavel
A1 - Kreft, Holger
T1 - Source pools and disharmony of the world’s island floras
JF - Ecography
N2 - Island disharmony refers to the biased representation of higher taxa on islands compared to their mainland source regions and represents a central concept in island biology. Here, we develop a generalizable framework for approximating these source regions and conduct the first global assessment of island disharmony and its underlying drivers. We compiled vascular plant species lists for 178 oceanic islands and 735 mainland regions. Using mainland data only, we modelled species turnover as a function of environmental and geographic distance and predicted the proportion of shared species between each island and mainland region. We then quantified the over- or under-representation of families on individual islands (representational disharmony) by contrasting the observed number of species against a null model of random colonization from the mainland source pool, and analysed the effects of six family-level functional traits on the resulting measure. Furthermore, we aggregated the values of representational disharmony per island to characterize overall taxonomic bias of a given flora (compositional disharmony), and analysed this second measure as a function of four island biogeographical variables. Our results indicate considerable variation in representational disharmony both within and among plant families. Examples of generally over-represented families include Urticaceae, Convolvulaceae and almost all pteridophyte families. Other families such as Asteraceae and Orchidaceae were generally under-represented, with local peaks of over-representation in known radiation hotspots. Abiotic pollination and a lack of dispersal specialization were most strongly associated with an insular over-representation of families, whereas other family-level traits showed minor effects. With respect to compositional disharmony, large, high-elevation islands tended to have the most disharmonic floras. Our results provide important insights into the taxon- and island-specific drivers of disharmony. The proposed framework allows overcoming the limitations of previous approaches and provides a quantitative basis for incorporating functional and phylogenetic approaches into future studies of island disharmony.
KW - assembly processes
KW - biotic filtering
KW - dispersal filtering
KW - environmental filtering
KW - generalized dissimilarity modelling
KW - island disharmony
KW - island syndromes
KW - source regions
KW - vascular plants
Y1 - 2020
VL - 44
IS - 1
PB - Wiley-Blackwell
CY - Oxford
ER -
TY - GEN
A1 - König, Christian
A1 - Weigelt, Patrick
A1 - Taylor, Amanda
A1 - Stein, Anke
A1 - Dawson, Wayne
A1 - Essl, Franz
A1 - Pergl, Jan
A1 - Pyšek, Petr
A1 - Kleunen, Mark van
A1 - Winter, Marten
A1 - Chatelain, Cyrille
A1 - Wieringa, Jan J.
A1 - Krestov, Pavel
A1 - Kreft, Holger
T1 - Source pools and disharmony of the world’s island floras
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Island disharmony refers to the biased representation of higher taxa on islands compared to their mainland source regions and represents a central concept in island biology. Here, we develop a generalizable framework for approximating these source regions and conduct the first global assessment of island disharmony and its underlying drivers. We compiled vascular plant species lists for 178 oceanic islands and 735 mainland regions. Using mainland data only, we modelled species turnover as a function of environmental and geographic distance and predicted the proportion of shared species between each island and mainland region. We then quantified the over- or under-representation of families on individual islands (representational disharmony) by contrasting the observed number of species against a null model of random colonization from the mainland source pool, and analysed the effects of six family-level functional traits on the resulting measure. Furthermore, we aggregated the values of representational disharmony per island to characterize overall taxonomic bias of a given flora (compositional disharmony), and analysed this second measure as a function of four island biogeographical variables. Our results indicate considerable variation in representational disharmony both within and among plant families. Examples of generally over-represented families include Urticaceae, Convolvulaceae and almost all pteridophyte families. Other families such as Asteraceae and Orchidaceae were generally under-represented, with local peaks of over-representation in known radiation hotspots. Abiotic pollination and a lack of dispersal specialization were most strongly associated with an insular over-representation of families, whereas other family-level traits showed minor effects. With respect to compositional disharmony, large, high-elevation islands tended to have the most disharmonic floras. Our results provide important insights into the taxon- and island-specific drivers of disharmony. The proposed framework allows overcoming the limitations of previous approaches and provides a quantitative basis for incorporating functional and phylogenetic approaches into future studies of island disharmony.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1211
KW - assembly processes
KW - biotic filtering
KW - dispersal filtering
KW - environmental filtering
KW - generalized dissimilarity modelling
KW - island disharmony
KW - island syndromes
KW - source regions
KW - vascular plants
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525101
SN - 1866-8372
IS - 1
ER -
TY - JOUR
A1 - Marquart, Arnim
A1 - Goldbach, Lars
A1 - Blaum, Niels
T1 - Soil-texture affects the influence of termite macropores on soil water infiltration in a semi-arid savanna
JF - Ecohydrology : ecosystems, land and water process interactions, ecohydrogeomorphology
N2 - Subterranean termites create tunnels (macropores) for foraging that can influence water infiltration and may lead to preferential flow to deeper soil layers. This is particularly important in water limited ecosystems such as semi-arid, agriculturally utilized savannas, which are particularly prone to land degradation and shrub-encroachment. Using termite activity has been suggested as a restoration measure, but their impact on hydrology is neither universal nor yet fully understood. Here, we used highly replicated, small-scale (50 x 50 cm) rain-simulation experiments to analyse the interacting effects of either vegetation (grass dominated vs. shrub dominated sites) or soil texture (sand vs. loamy sand) and termite foraging macropores on infiltration patterns. We used Brilliant Blue FCF as colour tracer to make the flow pathways in paired experiments visible, on either termite-disturbed soil or controls without surface macropores in two semi-arid Namibian savannas (with either heterogeneous soil texture or shrub cover). On highly shrub-encroached plots in the savanna site with heterogeneous soil texture, termite macropores increased maximum infiltration depth and total amount of infiltrated water on loamy sand, but not on sandy soil. In the sandy savanna with heterogeneous shrub cover, neither termite activity nor shrub density affected the infiltration. Termite's effect on infiltration depends on the soil's hydraulic conductivity and occurs mostly under ponded conditions, intercepting run-off. In semi-arid savanna soils with a considerable fraction of fine particles, termites are likely an important factor for soil water dynamics.
KW - ecosystem functioning
KW - infiltration
KW - macropores
KW - rain-simulation
KW - shrub-encroachment
KW - soil texture
KW - termites
Y1 - 2020
U6 - https://doi.org/10.1002/eco.2249
SN - 1936-0584
SN - 1936-0592
VL - 13
IS - 8
PB - Wiley
CY - Chichester
ER -
TY - JOUR
A1 - Mazza, Valeria
A1 - Dammhahn, Melanie
A1 - Lösche, Elisa
A1 - Eccard, Jana
T1 - Small mammals in the big city
BT - behavioural adjustments of non-commensal rodents to urban environments
JF - Global change biology
N2 - A fundamental focus of current ecological and evolutionary research is to illuminate the drivers of animals' success in coping with human-induced rapid environmental change (HIREC). Behavioural adaptations are likely to play a major role in coping with HIREC because behaviour largely determines how individuals interact with their surroundings. A substantial body of research reports behavioural modifications in urban dwellers compared to rural conspecifics. However, it is often unknown whether the observed phenotypic divergence is due to phenotypic plasticity or the product of genetic adaptations. Here, we aimed at investigating (a) whether behavioural differences arise also between rural and urban populations of non-commensal rodents; and (b) whether these differences result from behavioural flexibility or from intrinsic behavioural characteristics, such as genetic or maternal effects. We captured and kept under common environment conditions 42 rural and 52 urban adult common voles (Microtus arvalis) from seven subpopulations along a rural-urban gradient. We investigated individual variation in behavioural responses associated with risk-taking and exploration, in situ at the time of capture in the field and ex situ after 3 months in captivity. Urban dwellers were bolder and more explorative than rural conspecifics at the time of capture in their respective sites (in situ). However, when tested under common environmental conditions ex situ, rural individuals showed little change in their behavioural responses whereas urban individuals altered their behaviour considerably and were consistently shyer and less explorative than when tested in situ. The combination of elevated risk-taking and exploration with high behavioural flexibility might allow urban populations to successfully cope with the challenges of HIREC. Investigating whether the observed differences in behavioural flexibility are adaptive and how they are shaped by additive and interactive effects of genetic make-up and past environmental conditions will help illuminate eco-evolutionary dynamics under HIREC and predict persistence of populations under urban conditions.
KW - animal personality
KW - behavioural adjustment
KW - behavioural flexibility
KW - environmental change
KW - HIREC
KW - rodents
KW - urbanization
Y1 - 2020
U6 - https://doi.org/10.1111/gcb.15304
SN - 1354-1013
SN - 1365-2486
VL - 26
IS - 11
SP - 6326
EP - 6337
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Kurbanoglu, Sevinc
A1 - Yarman, Aysu
T1 - Simultaneous determination of hydrochlorothiazide and irbesartan from pharmaceutical dosage forms with RP-HPLC
T1 - Farmasötik Dozaj Formlarında TF-YPSK ile Hidroklorotiyazid ve
İrbesartanın Eş Zamanlı Tayini
JF - Turkish journal of pharmaceutical sciences
N2 - Objectives: In this work, a simple and rapid liquid chromatographic method for the simultaneous determination of irbesartan (IRBE) and hydrochlorothiazide (HCT) was developed and validated by reverse phase high performance liquid chromatography (RP-HPLC).
Materials and Methods: Experimental conditions such as different buffer solutions, various pH values, temperature, composition of the mobile phase, and the effect of flow rate were optimized.
Results: The developed RP-HPLC method for these antihypertensive agents was wholly validated and IRBE was detected in the linear range of 0.1-25 mu g mL(-1) and HCT was detected in the linear range of 0.25-25 mu g mL(-1). Moreover, the suggested chromatographic technique was successfully applied for the determination of the drugs in human serum and pharmaceutical dosage forms with limit of detection values of 0.008 mu g mL(-1) for IRBE and 0.012 mu g mL(-1) for HCT.
Conclusion: The proposed rapid analysis method of these antihypertensive drugs can be easily used and applied by pharmaceutical companies for which the analysis time is important.
N2 - Amaç: Bu çalışmada, irbesartan (IRBE) ve hidroklorotiyazidin (HCT) eşzamanlı tayini için basit ve hızlı bir ters fazlı yüksek performanslı sıvı
kromatografisi (TF-YPSK) yöntemi geliştirilmiş ve validasyon çalışmaları yapılmıştır.
Gereç ve Yöntemler: Deneysel koşullar; farklı tampon çözeltileri, çeşitli pH değerleri, sıcaklık, mobil fazın bileşimi, akış hızının etkisi gibi
parametrelerin üzerinden optimize edildi.
Bulgular: Bu antihipertansif ajanlar için geliştirilen TF-YPSK yönteminin tüm validasyon parametrelerine ilişkin çalışmalar yapılmış, ve IRBE 0,1-25
μg mL-1 doğrusal aralığında ve HCT 0,25-25 μg mL-1 doğrusal aralığında tespit edilmiştir. Ayrıca önerilen TF-YPSK yöntemi ile IRBE için 0,008 μg
mL-1 ve HCT için 0,012 μg mL-1 tayin alt sınır değerleri bulunmuştur. Geliştirilen yöntem, insan serumunda ve farmasötik dozaj formlarında bulunan
IRBE ve HCT’nin belirlenmesi için başarıyla uygulanmıştır.
Sonuç: Bu antihipertansif ilaçların miktar tayininde önerilen YPSK analiz yönteminin, analiz süresinin önemli olduğu ilaç firmalarında rahatlıkla
kullanılabileceği ve uygulanabileceği düşünülmektedir.
KW - HPLC
KW - irbesartan
KW - hydrochlorothiazide
KW - pharmaceutical dosage forms
Y1 - 2020
U6 - https://doi.org/10.4274/tjps.galenos.2019.76094
SN - 1304-530X
VL - 17
IS - 5
SP - 523
EP - 527
PB - Turkish Pharmacists Association
CY - Çankaya-Ankara
ER -
TY - JOUR
A1 - Baxa, Ulrich
A1 - Weintraub, Andrej
A1 - Seckler, Robert
T1 - Self-competitive inhibition of the bacteriophage P22 Tailspike endorhamnosidase by O-antigen oligosaccharides
JF - Biochemistry
N2 - The P22 tailspike endorhamnosidase confers the high specificity of bacteriophage P22 for some serogroups of Salmonella differing only slightly in their O-antigen polysaccharide. We used several biophysical methods to study the binding and hydrolysis of O-antigen fragments of different lengths by P22 tailspike protein. O-Antigen saccharides of defined length labeled with fluorophors could be purified with higher resolution than previously possible. Small amounts of naturally occurring variations of 0antigen fragments missing the nonreducing terminal galactose could be used to determine the contribution of this part to the free energy of binding to be similar to 7 kJ/mol. We were able to show via several independent lines of evidence that an unproductive binding mode is highly favored in binding over all other possible binding modes leading to hydrolysis. This is true even under circumstances under which the O-antigen fragment is long enough to be cleaved efficiently by the enzyme. The high-affinity unproductive binding mode results in a strong self-competitive inhibition in addition to product inhibition observed for this system. Self-competitive inhibition is observed for all substrates that have a free reducing end rhamnose. Naturally occurring O-antigen, while still attached to the bacterial outer membrane, does not have a free reducing end and therefore does not perform self-competitive inhibition.
Y1 - 2020
U6 - https://doi.org/10.1021/acs.biochem.0c00872
SN - 0006-2960
VL - 59
IS - 51
SP - 4845
EP - 4855
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Wolff, Martin
A1 - Schüler, Anja
A1 - Gast, Klaus
A1 - Seckler, Robert
A1 - Evers, Andreas
A1 - Pfeiffer-Marek, Stefania
A1 - Kurz, Michael
A1 - Nagel, Norbert
A1 - Haack, Torsten
A1 - Wagner, Michael
A1 - Thalhammer, Anja
T1 - Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains
JF - Molecular pharmaceutics
N2 - Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.
KW - dual GLP-1/glucagon receptor agonist
KW - self-assembly
KW - light scattering
KW - molecular architecture
KW - lipidation
KW - exendin-4
Y1 - 2020
U6 - https://doi.org/10.1021/acs.molpharmaceut.9b01195
SN - 1543-8384
VL - 17
IS - 3
SP - 965
EP - 978
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Wolff, Martin
A1 - Schüler, Anja
A1 - Gast, Klaus
A1 - Seckler, Robert
A1 - Evers, Andreas
A1 - Pfeiffer-Marek, Stefania
A1 - Kurz, Michael
A1 - Nagel, Norbert
A1 - Haack, Torsten
A1 - Wagner, Michael
A1 - Thalhammer, Anja
T1 - Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains
JF - Molecular pharmaceutics
N2 - Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.
KW - dual GLP-1/glucagon receptor agonist
KW - self-assembly
KW - light scattering
KW - molecular architecture
KW - lipidation
KW - exendin-4
Y1 - 2020
U6 - https://doi.org/10.1021/acs.molpharmaceut.9b01195
SN - 1543-8384
SN - 1543-8392
VL - 17
IS - 3
SP - 965
EP - 978
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Thirumalaikumar, Venkatesh P.
A1 - Gorka, Michal
A1 - Schulz, Karina
A1 - Masclaux-Daubresse, Celine
A1 - Sampathkumar, Arun
A1 - Skirycz, Aleksandra
A1 - Vierstra, Richard D.
A1 - Balazadeh, Salma
T1 - Selective autophagy regulates heat stress memory in Arabidopsis by NBR1-mediated targeting of HSP90.1 and ROF1
JF - Autophagy
N2 - In nature, plants are constantly exposed to many transient, but recurring, stresses. Thus, to complete their life cycles, plants require a dynamic balance between capacities to recover following cessation of stress and maintenance of stress memory. Recently, we uncovered a new functional role for macroautophagy/autophagy in regulating recovery from heat stress (HS) and resetting cellular memory of HS inArabidopsis thaliana. Here, we demonstrated that NBR1 (next to BRCA1 gene 1) plays a crucial role as a receptor for selective autophagy during recovery from HS. Immunoblot analysis and confocal microscopy revealed that levels of the NBR1 protein, NBR1-labeled puncta, and NBR1 activity are all higher during the HS recovery phase than before. Co-immunoprecipitation analysis of proteins interacting with NBR1 and comparative proteomic analysis of annbr1-null mutant and wild-type plants identified 58 proteins as potential novel targets of NBR1. Cellular, biochemical and functional genetic studies confirmed that NBR1 interacts with HSP90.1 (heat shock protein 90.1) and ROF1 (rotamase FKBP 1), a member of the FKBP family, and mediates their degradation by autophagy, which represses the response to HS by attenuating the expression ofHSPgenes regulated by the HSFA2 transcription factor. Accordingly, loss-of-function mutation ofNBR1resulted in a stronger HS memory phenotype. Together, our results provide new insights into the mechanistic principles by which autophagy regulates plant response to recurrent HS.
KW - Arabidopsis thaliana
KW - heat stress
KW - HSFA2
KW - HSP90.1
KW - NBR1
KW - ROF1
KW - selective autophagy
KW - stress memory
KW - stress recovery
Y1 - 2020
U6 - https://doi.org/10.1080/15548627.2020.1820778
SN - 1554-8635
VL - 17
IS - 9
SP - 2184
EP - 2199
PB - Taylor & Francis
CY - Abingdon
ER -
TY - JOUR
A1 - Hermanussen, Michael
A1 - Scheffler, Christiane
T1 - Secular trends in gestational weight gain and parity on birth weight
BT - an editorial
JF - Acta paediatrica : nurturing the child
KW - birth weight
KW - gestational weight gain
KW - multipara
KW - parity
KW - primipara
KW - secular trend
Y1 - 2020
U6 - https://doi.org/10.1111/apa.15678
SN - 0803-5253
SN - 1651-2227
VL - 110
IS - 4
SP - 1094
EP - 1096
PB - Wiley
CY - Oxford
ER -
TY - JOUR
A1 - Abdirashid, Hashim
A1 - Lenhard, Michael
T1 - Say it with double flowers
JF - Journal of experimental botany
N2 - Every year, lovers world-wide rely on mutants to show their feelings on Valentine's Day. This is because many of the most popular ornamental flowering plants have been selected to form extra petals at the expense of reproductive organs to enhance their attractiveness and aesthetic value to humans. This so-called 'double flower' (DF) phenotype, first described more than 2000 years ago (Meyerowitz et al., 1989) is present, for example, in many modern roses, carnations, peonies, and camellias. Gattolin et al. (2020) now identify a unifying explanation for the molecular basis of many of these DF cultivars.
KW - ABCE model
KW - APETALA2
KW - double flowers
KW - flower development
KW - homoeotic
KW - mutants
KW - microRNA172
Y1 - 2020
U6 - https://doi.org/10.1093/jxb/eraa109
SN - 0022-0957
SN - 1460-2431
VL - 71
IS - 9
SP - 2469
EP - 2471
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - GEN
A1 - des Aulnois, Maxime Georges
A1 - Réveillon, Damien
A1 - Robert, Elise
A1 - Caruana, Amandine
A1 - Briand, Enora
A1 - Guljamow, Arthur
A1 - Dittmann, Elke
A1 - Amzil, Zouher
A1 - Bormans, Myriam
T1 - Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the effect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by differences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the brackish strain. The production of intracellular microcystin variants in response to salt stress correlated well to the growth rate for both strains. Furthermore, the release of microcystins into the surrounding medium only occurred at the highest salinity treatment when cell lysis occurred. This study suggests that the physiological responses of M. aeruginosa involve the accumulation of common metabolites but that the intraspecific salt tolerance is based on the accumulation of specific metabolites. While one of these was determined to be sucrose, many others remain to be identified. Taken together, these results provide evidence that M. aeruginosa is relatively salt tolerant in the mesohaline zone and microcystin (MC) release only occurs when the capacity of the cells to deal with salt increase is exceeded.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1130
KW - Microcystis aeruginosa
KW - microcystin
KW - salt stress
KW - metabolomic
KW - transcript
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472405
SN - 1866-8372
IS - 1130
ER -
TY - JOUR
A1 - des Aulnois, Maxime Georges
A1 - Réveillon, Damien
A1 - Robert, Elise
A1 - Caruana, Amandine
A1 - Briand, Enora
A1 - Guljamow, Arthur
A1 - Dittmann, Elke
A1 - Amzil, Zouher
A1 - Bormans, Myriam
T1 - Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses
JF - Toxins
N2 - The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the effect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by differences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the brackish strain. The production of intracellular microcystin variants in response to salt stress correlated well to the growth rate for both strains. Furthermore, the release of microcystins into the surrounding medium only occurred at the highest salinity treatment when cell lysis occurred. This study suggests that the physiological responses of M. aeruginosa involve the accumulation of common metabolites but that the intraspecific salt tolerance is based on the accumulation of specific metabolites. While one of these was determined to be sucrose, many others remain to be identified. Taken together, these results provide evidence that M. aeruginosa is relatively salt tolerant in the mesohaline zone and microcystin (MC) release only occurs when the capacity of the cells to deal with salt increase is exceeded.
KW - Microcystis aeruginosa
KW - microcystin
KW - salt stress
KW - metabolomic
KW - transcript
Y1 - 2020
U6 - https://doi.org/10.3390/toxins12030192
SN - 2072-6651
VL - 12
IS - 3
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - van Rees, Charles B.
A1 - Waylen, Kerry A.
A1 - Schmidt-Kloiber, Astrid
A1 - Thackeray, Stephen J.
A1 - Kalinkat, Gregor
A1 - Martens, Koen
A1 - Domisch, Sami
A1 - Lillebo, Ana
A1 - Hermoso, Virgilio
A1 - Grossart, Hans-Peter
A1 - Schinegger, Rafaela
A1 - Decleer, Kris
A1 - Adriaens, Tim
A1 - Denys, Luc
A1 - Jaric, Ivan
A1 - Janse, Jan H.
A1 - Monaghan, Michael T.
A1 - De Wever, Aaike
A1 - Geijzendorffer, Ilse
A1 - Adamescu, Mihai C.
A1 - Jähnig, Sonja C.
T1 - Safeguarding freshwater life beyond 2020
BT - recommendations for the new global biodiversity framework from the European experience
JF - Conservation letters
N2 - Plans are currently being drafted for the next decade of action on biodiversity-both the post-2020 Global Biodiversity Framework of the Convention on Biological Diversity (CBD) and Biodiversity Strategy of the European Union (EU). Freshwater biodiversity is disproportionately threatened and underprioritized relative to the marine and terrestrial biota, despite supporting a richness of species and ecosystems with their own intrinsic value and providing multiple essential ecosystem services. Future policies and strategies must have a greater focus on the unique ecology of freshwater life and its multiple threats, and now is a critical time to reflect on how this may be achieved. We identify priority topics including environmental flows, water quality, invasive species, integrated water resources management, strategic conservation planning, and emerging technologies for freshwater ecosystem monitoring. We synthesize these topics with decades of first-hand experience and recent literature into 14 special recommendations for global freshwater biodiversity conservation based on the successes and setbacks of European policy, management, and research. Applying and following these recommendations will inform and enhance the ability of global and European post-2020 biodiversity agreements to halt and reverse the rapid global decline of freshwater biodiversity.
KW - climate change
KW - conservation
KW - ecosystem services
KW - rivers
KW - sustainable
KW - development goals
KW - water resources
KW - wetlands
Y1 - 2020
U6 - https://doi.org/10.1111/conl.12771
SN - 1755-263X
VL - 14
IS - 1
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Lenzner, Bernd
A1 - Magallon, Susana
A1 - Dawson, Wayne
A1 - Kreft, Holger
A1 - König, Christian
A1 - Pergl, Jan
A1 - Pysek, Petr
A1 - Weigelt, Patrick
A1 - van Kleunen, Mark
A1 - Winter, Marten
A1 - Dullinger, Stefan
A1 - Essl, Franz
T1 - Role of diversification rates and evolutionary history as a driver of plant naturalization success
JF - New phytologist : international journal of plant science
N2 - Human introductions of species beyond their natural ranges and their subsequent establishment are defining features of global environmental change. However, naturalized plants are not uniformly distributed across phylogenetic lineages, with some families contributing disproportionately more to the global alien species pool than others. Additionally, lineages differ in diversification rates, and high diversification rates have been associated with characteristics that increase species naturalization success. Here, we investigate the role of diversification rates in explaining the naturalization success of angiosperm plant families.
We use five global data sets that include native and alien plant species distribution, horticultural use of plants, and a time-calibrated angiosperm phylogeny. Using phylogenetic generalized linear mixed models, we analysed the effect of diversification rate, different geographical range measures, and horticultural use on the naturalization success of plant families.
We show that a family's naturalization success is positively associated with its evolutionary history, native range size, and economic use. Investigating interactive effects of these predictors shows that native range size and geographic distribution additionally affect naturalization success. High diversification rates and large ranges increase naturalization success, especially of temperate families.
We suggest this may result from lower ecological specialization in temperate families with large ranges, compared with tropical families with smaller ranges.
KW - alien species
KW - evolution
KW - geographic distribution
KW - invasion success
KW - plant naturalization
KW - range size
Y1 - 2020
U6 - https://doi.org/10.1111/nph.17014
SN - 0028-646X
SN - 1469-8137
VL - 229
IS - 5
SP - 2998
EP - 3008
PB - Wiley
CY - Hoboken
ER -
TY - GEN
A1 - Lenzner, Bernd
A1 - Magallon, Susana
A1 - Dawson, Wayne
A1 - Kreft, Holger
A1 - König, Christian
A1 - Pergl, Jan
A1 - Pysek, Petr
A1 - Weigelt, Patrick
A1 - van Kleunen, Mark
A1 - Winter, Marten
A1 - Dullinger, Stefan
A1 - Essl, Franz
T1 - Role of diversification rates and evolutionary history as a driver of plant naturalization success
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Human introductions of species beyond their natural ranges and their subsequent establishment are defining features of global environmental change. However, naturalized plants are not uniformly distributed across phylogenetic lineages, with some families contributing disproportionately more to the global alien species pool than others. Additionally, lineages differ in diversification rates, and high diversification rates have been associated with characteristics that increase species naturalization success. Here, we investigate the role of diversification rates in explaining the naturalization success of angiosperm plant families.
We use five global data sets that include native and alien plant species distribution, horticultural use of plants, and a time-calibrated angiosperm phylogeny. Using phylogenetic generalized linear mixed models, we analysed the effect of diversification rate, different geographical range measures, and horticultural use on the naturalization success of plant families.
We show that a family's naturalization success is positively associated with its evolutionary history, native range size, and economic use. Investigating interactive effects of these predictors shows that native range size and geographic distribution additionally affect naturalization success. High diversification rates and large ranges increase naturalization success, especially of temperate families.
We suggest this may result from lower ecological specialization in temperate families with large ranges, compared with tropical families with smaller ranges.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1363
KW - alien species
KW - evolution
KW - geographic distribution
KW - invasion success
KW - plant naturalization
KW - range size
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-569996
SN - 1866-8372
IS - 5
ER -
TY - GEN
A1 - Hermanussen, Michael
A1 - Scheffler, Christiane
A1 - Pulungan, Aman B.
A1 - Batubara, Jose R. L.
A1 - Julia, Madarina
A1 - Bogin, Barry
T1 - Response to the correspondence referring to our article "Stunting is not a synonym of malnutrition" (2018EJCN0997RR) by Conny Tanjung, Titis Prawitasari, Damayanti Rusli Sjarif
T2 - European journal of clinical nutrition
Y1 - 2020
U6 - https://doi.org/10.1038/s41430-020-0571-1
SN - 0954-3007
SN - 1476-5640
VL - 74
IS - 3
SP - 529
EP - 531
PB - Nature Publ. Group
CY - New York, NY
ER -
TY - GEN
A1 - Weise, Hanna
A1 - Auge, Harald
A1 - Baessler, Cornelia
A1 - Bärlund, Ilona
A1 - Bennett, Elena M.
A1 - Berger, Uta
A1 - Bohn, Friedrich
A1 - Bonn, Aletta
A1 - Borchardt, Dietrich
A1 - Brand, Fridolin
A1 - Jeltsch, Florian
A1 - Joshi, Jasmin Radha
A1 - Grimm, Volker
T1 - Resilience trinity
BT - Safeguarding ecosystem functioning and services across three different time horizons and decision contexts
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi-faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time-horizons: 1) reactive, when there is an imminent threat to ES resilience and a high pressure to act, 2) adjustive, when the threat is known in general but there is still time to adapt management and 3) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology and engineering are often implicitly focussing on provident, adjustive or reactive resilience, respectively, but these different notions of resilience and their corresponding social, ecological and economic tradeoffs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer-term management actions are not missed while urgent threats to ES are given priority.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1444
KW - concepts
KW - ecosystems
KW - ecosystem services provisioning
KW - management
KW - resilience
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515284
SN - 1866-8372
IS - 4
ER -
TY - JOUR
A1 - Weise, Hanna
A1 - Auge, Harald
A1 - Baessler, Cornelia
A1 - Bärlund, Ilona
A1 - Bennett, Elena M.
A1 - Berger, Uta
A1 - Bohn, Friedrich
A1 - Bonn, Aletta
A1 - Borchardt, Dietrich
A1 - Brand, Fridolin
A1 - Jeltsch, Florian
A1 - Joshi, Jasmin Radha
A1 - Grimm, Volker
T1 - Resilience trinity
BT - safeguarding ecosystem functioning and services across three different time horizons and decision contexts
JF - Oikos
N2 - Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi-faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time-horizons: 1) reactive, when there is an imminent threat to ES resilience and a high pressure to act, 2) adjustive, when the threat is known in general but there is still time to adapt management and 3) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology and engineering are often implicitly focussing on provident, adjustive or reactive resilience, respectively, but these different notions of resilience and their corresponding social, ecological and economic tradeoffs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer-term management actions are not missed while urgent threats to ES are given priority.
KW - concepts
KW - ecosystems
KW - ecosystem services provisioning
KW - management
KW - resilience
Y1 - 2020
U6 - https://doi.org/10.1111/oik.07213
SN - 0030-1299
SN - 1600-0706
VL - 129
IS - 4
SP - 445
EP - 456
PB - Wiley-Blackwell
CY - Oxford
ER -
TY - JOUR
A1 - Fichtner, Franziska
A1 - Barbier, Francois F.
A1 - Annunziata, Maria Grazia
A1 - Feil, Regina
A1 - Olas, Justyna Jadwiga
A1 - Müller-Röber, Bernd
A1 - Stitt, Mark
A1 - Beveridge, Christine A.
A1 - Lunn, John Edward
T1 - Regulation of shoot branching in arabidopsis by trehalose 6-phosphate
JF - New phytologist : international journal of plant science
N2 - Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood.
We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds.
TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds.
These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT.
KW - Arabidopsis thaliana (arabidopsis)
KW - axillary bud
KW - branching
KW - sucrose
KW - sugar signalling
KW - trehalose 6‐ phosphate (Tre6P)
Y1 - 2020
U6 - https://doi.org/10.1111/nph.17006
SN - 0028-646X
SN - 1469-8137
VL - 229
IS - 4
SP - 2135
EP - 2151
PB - Wiley
CY - Hoboken
ER -
TY - GEN
A1 - Fichtner, Franziska
A1 - Barbier, Francois F.
A1 - Annunziata, Maria Grazia
A1 - Feil, Regina
A1 - Olas, Justyna Jadwiga
A1 - Müller-Röber, Bernd
A1 - Stitt, Mark
A1 - Beveridge, Christine A.
A1 - Lunn, John Edward
T1 - Regulation of shoot branching in arabidopsis by trehalose 6-phosphate
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood.
We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds.
TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds.
These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1383
KW - Arabidopsis thaliana (arabidopsis)
KW - axillary bud
KW - branching
KW - sucrose
KW - sugar signalling
KW - trehalose 6‐ phosphate (Tre6P)
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-569564
SN - 1866-8372
IS - 4
ER -
TY - THES
A1 - Siemiatkowska, Beata
T1 - Redox signalling in plants
N2 - Once proteins are synthesized, they can additionally be modified by post-translational modifications (PTMs). Proteins containing reactive cysteine thiols, stabilized in their deprotonated form due to their local environment as thiolates (RS-), serve as redox sensors by undergoing a multitude of oxidative PTMs (Ox-PTMs). Ox-PTMs such as S-nitrosylation or formation of inter- or intra-disulfide bridges induce functional changes in these proteins. Proteins containing cysteines, whose thiol oxidation state regulates their functions, belong to the so-called redoxome. Such Ox-PTMs are controlled by site-specific cellular events that play a crucial role in protein regulation, affecting enzyme catalytic sites, ligand binding affinity, protein-protein interactions or protein stability. Reversible protein thiol oxidation is an essential regulatory mechanism of photosynthesis, metabolism, and gene expression in all photosynthetic organisms. Therefore, studying PTMs will remain crucial for understanding plant adaptation to external stimuli like fluctuating light conditions. Optimizing methods suitable for studying plants Ox-PTMs is of high importance for elucidation of the redoxome in plants. This study focusses on thiol modifications occurring in plant and provides novel insight into in vivo redoxome of Arabidopsis thaliana in response to light vs. dark. This was achieved by utilizing a resin-assisted thiol enrichment approach. Furthermore, confirmation of candidates on the single protein level was carried out by a differential labelling approach. The thiols and disulfides were differentially labelled, and the protein levels were detected using immunoblot analysis. Further analysis was focused on light-reduced proteins. By the enrichment approach many well studied redox-regulated proteins were identified. Amongst those were fructose 1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase) which have previously been described as thioredoxin system targeted enzymes. The redox regulated proteins identified in the current study were compared to several published, independent results showing redox regulated proteins in Arabidopsis leaves, root, mitochondria and specifically S-nitrosylated proteins. These proteins were excluded as potential new candidates but remain as a proof-of-concept to the enrichment experiments to be effective. Additionally, CSP41A and CSP41B proteins, which emerged from this study as potential targets of redox-regulation, were analyzed by Ribo-Seq. The active translatome study of csp41a mutant vs. wild-type showed most of the significant changes at end of the night, similarly as csp41b. Yet, in both mutants only several chloroplast-encoded genes were altered. Further studies of CSP41A and CSP41B proteins are needed to reveal their functions and elucidate the role of redox regulation of these proteins.
N2 - Wenn Proteine synthetisiert sind, können sie zusätzlich noch post-translationelle Modifikationen (PTM) aufweisen. Proteine, die wegen ihres lokalen Umfeldes reaktive Cysteinthiole in ihrer stabilen deprotonierten Thiolat-Form aufweisen, dienen als Redoxsensoren indem sie eine Vielzahl von oxidativen PTMs (Ox-PTMs) enthalten können. Ox-PTMs wie die S-Nitrosylierung oder die Bildung von Inter- oder Intradisulfidbrücken induzieren funktionelle Veränderungen in diesen Proteinen. Cystein-haltige Proteine, deren Funktion durch diese Thioloxidierung gesteuert werden, gehören zu dem so genannten Redoxom. Die Ox-PTMs werden durch ortsspezifische zelluläre Prozesse gesteuert, die eine essentielle Rolle bei der Proteinregulation spielen und welche das katalytische Zentrum, die Ligandenbindungsaffinität, Protein-Protein-Interaktionen oder die Proteinstabilität beeinflussen können. Die umkehrbare Proteinthioloxidierung ist ein essentieller regulatorischer Mechanismus in der Photosynthese, dem Metabolismus und der Genexpression photosynthetischer Organismen. Es ist demnach wichtig PTMs zu untersuchen, um zu verstehen wie sich Pflanzen an externe Stimuli wie das Licht anpassen können. Es ist von großer Bedeutung für das Redoxom-Forschungsgebiet Methoden zur Untersuchung von pflanzlichen Ox-PTMs zu verbessern. Die vorliegende Arbeit konzentriert sich auf Thiolveränderungen, die in Pflanzen auftreten, und gibt einen Einblick in das in vivo Redoxom von Arabidopsis thaliana als Reaktion auf Licht oder Dunkelheit. Dieses wurde ermöglicht durch eine auf Harz-basierende Thiol-Anreicherung. Darüber hinaus konnten Kandidaten auf dem Einzelproteinlevel durch eine Differentialmarkierungsmethode bestätigt werden. Thiole und Disulfide wurden unterschiedlich markiert und die Proteine durch spezifische Antikörper mittels Proteinblotanalyse erkannt. Weitere Analysen fokussierten sich auf im Licht reduzierte Proteine. Durch die Anreicherungsmethode konnten viele bereits untersuchte redox-regulierte Proteine identifiziert werden. Unter diesen waren unter anderem die Fruktose-1,6-Bisphosphatase (FBPase) sowie die Seduheptulose-1,7-Bisphosphatase (SBPase), welche als Thioredoxin-gesteuerte Enzyme beschrieben sind. Die redox-regulierten Proteine, die in dieser Studie identifiziert werden konnten, wurden mit veröffentlichten unabhängigen Ergebnissen verglichen und dieses führte zu einer Vielzahl an redox-regulierten Proteinen in Arabidopsisblättern, -Wurzeln und -Mitochondrien sowie S-nitrosylierten Proteinen. Diese Proteine wurden zwar als neue potentielle Kandidaten ausgeschlossen, zeigten allerdings die Effektivität der Anreicherungsmethode. Darüber hinaus wurden die Proteine CSP41 A and CSP41 B, welche in dieser Studie als potentielle Ziele der Redox-Regulation identifiziert wurden, durch Ribo-seq analysiert.
T2 - Redoxsignalisierung in Pflanzen
KW - redox
KW - signalling
KW - plants
KW - enrichments methods
KW - post-translational modifications
KW - oxidative protein modifications
KW - Redox
KW - Signalübertragung
KW - Pflanzen
KW - Anreicherungsmethoden
KW - posttranslationale Modifikationen
KW - oxidative Proteinmodifikationen
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-489119
ER -
TY - JOUR
A1 - Hofreiter, Michael
A1 - Hartmann, Stefanie
T1 - Reconstructing protein-coding sequences from ancient DNA
JF - Odorant binding and chemosensory proteins
N2 - Obtaining information about functional details of proteins of extinct species is of critical importance for a better understanding of the real-life appearance, behavior and ecology of these lost entries in the book of life. In this chapter, we discuss the possibilities to retrieve the necessary DNA sequence information from paleogenomic data obtained from fossil specimens, which can then be used to express and subsequently analyze the protein of interest. We discuss the problems specific to ancient DNA, including mis-coding lesions, short read length and incomplete paleogenome assemblies. Finally, we discuss an alternative, but currently rarely used approach, direct PCR amplification, which is especially useful for comparatively short proteins.
KW - re-sequencing
KW - mapping
KW - genome assembly
KW - targeted assembly
KW - SRAssembler
KW - ancient DNA
KW - reference sequence
KW - paleogenomics
Y1 - 2020
SN - 978-0-12-821157-1
U6 - https://doi.org/10.1016/bs.mie.2020.05.008
SN - 0076-6879
VL - 642
SP - 21
EP - 33
PB - Academic Press, an imprint of Elsevier
CY - Cambridge, MA.
ER -
TY - JOUR
A1 - Steppert, Claus
A1 - Steppert, Isabel
A1 - Bollinger, Thomas
A1 - Sterlacci, William
T1 - Rapid non-invasive detection of Influenza-A-infection by multicapillary column coupled ion mobility spectrometry
JF - Journal of breath research : volatiles for medical diagnosis ; official journal of the International Association for Breath Research (IABR) and the International Society for Breath Odor Research (ISBOR)
N2 - Infectious pathogens are a global issue. Global air travel offers an easy and fast opportunity not only for people but also for infectious diseases to spread around the world within a few days. Also, large public events facilitate increasing infection numbers. Therefore, rapid on-site screening for infected people is urgently needed. Due to the small size and easy handling, ion mobility spectrometry coupled with a multicapillary column (MCC-IMS) is a very promising, sensitive method for the on-site identification of infectious pathogens based on scents, representing volatile organic compounds (VOCs). The purpose of this study was to prospectively assess whether identification of Influenza-A-infection based on VOCs by MCC-IMS is possible in breath. Nasal breath was investigated in 24 consecutive persons with and without Influenza-A-infection by MCC-IMS. In 14 Influenza-A-infected patients, infection was proven by PCR of nasopharyngeal swabs. Four healthy staff members and six patients with negative PCR result served as controls. For picking up relevant VOCs in MCC-IMS spectra, software based on cluster analysis followed by multivariate statistical analysis was applied. With only four VOCs canonical discriminant analysis was able to distinguish Influenza-A-infected patients from those not infected with 100% sensitivity and 100% specificity. This present proof-of-concept-study yields encouraging results showing a rapid diagnosis of viral infections in nasal breath within 5 min by MCC-IMS. The next step is to validate the results with a greater number of patients with Influenza-A-infection as well as other viral diseases, especially COVID-19. Registration number at ClinicalTrials.gov NCT04282135.
KW - Influenza-A
KW - ion mobility spectrometry
KW - rapid diagnosis
KW - breath
Y1 - 2020
U6 - https://doi.org/10.1088/1752-7163/abb762
SN - 1752-7163
VL - 15
IS - 1
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Nawaz, Shiza
A1 - Khan, Muhammad Moman
A1 - Noack, Jonas
A1 - Awan, Asad Bashir
A1 - Schiebel, Juliane
A1 - Roggenbuck, Dirk
A1 - Schierack, Peter
A1 - Sarwar, Yasra
A1 - Ali, Aamir
T1 - Rapid detection of biofilm formation by zoonotic serovars of Salmonella enterica and avian pathogenic E. coli isolates from poultry
JF - Pakistan veterinary journal
N2 - Biofilms are complex, sessile microbial communities that are problematic in clinical settings due to their association with survival and pathogenicity of bacteria. The biofilm formation supporting conditions for zoonotic serovars of Salmonella and avian pathogenic E. coli (APEC) from poultry have not been well studied yet. Clinical isolates of zoonotic Salmonella and APEC from poultry were evaluated for biofilm formation in four media at 37 degrees C and 40 degrees C after incubation of 48 and 72 hrs. The biofilms formed in 96 well plates were visualized and quantified with a new module of Aklides system using fluorescence microscope coupled with automated VideoScan Technology. After 72 hrs, brain heart infusion at 40 degrees C and Rappaport-Vassiliadis Soya broth at 37 degrees C were found most suitable for APEC and Salmonella biofilm formations respectively. The new information will be useful for further biofilm associated studies particularly for evaluation of antibiofilm compounds and contribute in infection control. (C) 2020 PVJ. All rights reserved
KW - APEC
KW - biofilm formation
KW - Salmonella
KW - video scan technology
Y1 - 2020
U6 - https://doi.org/10.29261/pakvetj/2020.066
SN - 0253-8318
SN - 2074-7764
VL - 40
IS - 4
SP - 527
EP - 530
PB - University of Agriculture, Faculty of Veterinary Science
CY - Faisalabad
ER -
TY - JOUR
A1 - Ziege, Madlen
A1 - Hermann, Bernd Timo
A1 - Kriesten, Stefanie
A1 - Merker, Stefan
A1 - Ullmann, Wiebke
A1 - Streit, Bruno
A1 - Wenninger, Sandra
A1 - Plath, Martin
T1 - Ranging behavior of European rabbits (Oryctolagus cuniculus) in urban and suburban landscapes
JF - Mammal research / Mammal Research Institute, Polish Academy of Sciences
N2 - Various mammals, particularly carnivores, reportedly establish smaller home ranges in urban compared with rural areas. This may be because urban environments provide optimal resources within a small area, negating the requirement to range further, or because habitat fragmentation constrains ranging behavior. Comparable information on urban populations of herbivorous mammalian species (such as European rabbits) is scarce. To fill this knowledge gap, we radio-tracked 13 individuals (seven females and six males) equipped with radio collars in a suburban and an urban study site in the city of Frankfurt am Main in Germany during the reproductive season (March to September) of 2012. The study sites differed in levels of habitat fragmentation. We report the smallest home ranges ever described for this species, with mean 95% minimum convex polygons (MCPs) covering 0.50 ha, while no consistent differences between sites were uncovered. We occasionally tracked individuals crossing streets underground (in burrows), suggesting that streets may restrict the ranging behavior of rabbits-and possibly other burrowing species-to a much lesser extent than previously thought. We conclude that heterogeneous landscape structures, made up of a diverse mosaic of buildings, parks, and gardens, provide sufficient food and shelter in close proximity to burrows at both study sites. Therefore, our data support the hypothesis that optimal resources constrain ranges in this case rather than habitat fragmentation.
KW - Habitat fragmentation
KW - Home range
KW - Urbanization
KW - Urban ecology
KW - Minimum convex polygons (MCPs)
Y1 - 2020
U6 - https://doi.org/10.1007/s13364-020-00490-2
SN - 2199-2401
SN - 2199-241X
VL - 65
IS - 3
SP - 607
EP - 614
PB - Springer
CY - Heidelberg
ER -
TY - JOUR
A1 - Faisal, Muhammad B.
A1 - Gechev, Tsanko S.
A1 - Müller-Röber, Bernd
A1 - Dijkwel, Paul P.
T1 - Putative alternative translation start site-encoding nucleotides of CPR5 regulate growth and resistance
JF - BMC plant biology
N2 - Background
The Arabidopsis CONSTITUTIVE EXPRESSER of PATHOGENESIS-RELATED GENES 5 (CPR5) has recently been shown to play a role in gating as part of the nuclear pore complex (NPC). Mutations in CPR5 cause multiple defects, including aberrant trichomes, reduced ploidy levels, reduced growth and enhanced resistance to bacterial and fungal pathogens. The pleiotropic nature of cpr5 mutations implicates that the CPR5 protein affects multiple pathways. However, little is known about the structural features that allow CPR5 to affect the different pathways.
Results
Our in silico studies suggest that in addition to three clusters of putative nuclear localization signals and four or five transmembrane domains, CPR5 contains two putative alternative translation start sites. To test the role of the methionine-encoding nucleotides implicated in those sites, metCPR5 cDNAs, in which the relevant nucleotides were changed to encode glutamine, were fused to the CPR5 native promoter and the constructs transformed to cpr5-2 plants to complement cpr5-compromised phenotypes. The control and metCPR5 constructs were able to complement all cpr5 phenotypes, although the extent of complementation depended on the specific complementing plant lines. Remarkably, plants transformed with metCPR5 constructs showed larger leaves and displayed reduced resistance when challenged to Pseudomonas syringae pv Pst DC3000, as compared to control plants. Thus, the methionine-encoding nucleotides regulate growth and resistance. We propose that structural features of the CPR5 N-terminus are implicated in selective gating of proteins involved in regulating the balance between growth and resistance.
Conclusion
Plants need to carefully balance the amount of resources used for growth and resistance. The Arabidopsis CPR5 protein regulates plant growth and immunity. Here we show that N-terminal features of CPR5 are involved in the regulation of the balance between growth and resistance. These findings may benefit efforts to improve plant yield, while maintaining optimal levels of disease resistance.
KW - CPR5
KW - plant growth
KW - disease resistance
KW - cell death
KW - arabidopsis thaliana
KW - endoreduplication
Y1 - 2020
U6 - https://doi.org/10.1186/s12870-020-02485-2
SN - 1471-2229
VL - 20
IS - 1
PB - BMC
CY - London
ER -
TY - THES
A1 - Küken, Anika
T1 - Predictions from constraint-based approaches including enzyme kinetics
N2 - The metabolic state of an organism reflects the entire phenotype that is jointly affected by genetic and environmental changes. Due to the complexity of metabolism, system-level modelling approaches have become indispensable tools to obtain new insights into biological functions. In particular, simulation and analysis of metabolic networks using constraint-based modelling approaches have helped the analysis of metabolic fluxes. However, despite ongoing improvements in prediction of reaction flux through a system, approaches to directly predict metabolite concentrations from large-scale metabolic networks remain elusive. In this thesis, we present a computational approach for inferring concentration ranges from genome-scale metabolic models endowed with mass action kinetics. The findings specify a molecular mechanism underling facile control of concentration ranges for components in large-scale metabolic networks. Most importantly, an extended version of the approach can be used to predict concentration ranges without knowledge of kinetic parameters, provided measurements of concentrations in a reference state. We show that the approach is applicable with large-scale kinetic and stoichiometric metabolic models of organisms from different kingdoms of life. By challenging the predictions of concentration ranges in the genome-scale metabolic network of Escherichia coli with real-world data sets, we further demonstrate the prediction power and limitations of the approach. To predict concentration ranges in other species, e.g. model plant species Arabidopsis thaliana, we would rely on estimates of kinetic parameters (i.e. enzyme catalytic rates) since plant-specific enzyme catalytic rates are poorly documented. Using the constraint-based approach of Davidi et al. for estimation of enzyme catalytic rates, we obtain values for 168 plant enzymes. The approach depends on quantitative proteomics data and flux estimates obtained from constraint-based model of plant leaf metabolism integrating maximal rates of selected enzymes, plant-specific constraints on fluxes through canonical pathways, and growth measurements from Arabidopsis thaliana rosette under ten conditions. We demonstrate a low degree of plant enzyme saturation, supported by the agreement between concentrations of nicotinamide adenine dinucleotide, adenosine triphosphate, and glyceraldehyde 3-phosphate, based on our maximal in vivo catalytic rates, and available quantitative metabolomics data. Hence, our results show genome-wide estimation for plant-specific enzyme catalytic rates is feasible. These can now be readily employed to study resource allocation, to predict enzyme and metabolite concentrations using recent constrained-based modelling approaches. Constraint-based methods do not directly account for kinetic mechanisms and corresponding parameters. Therefore, a number of workflows have already been proposed to approximate reaction kinetics and to parameterize genome-scale kinetic models. We present a systems biology strategy to build a fully parameterized large-scale model of Chlamydomonas reinhardtii accounting for microcompartmentalization in the chloroplast stroma. Eukaryotic algae comprise a microcompartment, the pyrenoid, essential for the carbon concentrating mechanism (CCM) that improves their photosynthetic performance. Since the experimental study of the effects of microcompartmentation on metabolic pathways is challenging, we employ our model to investigate compartmentation of fluxes through the Calvin-Benson cycle between pyrenoid and stroma. Our model predicts that ribulose-1,5-bisphosphate, the substrate of Rubisco, and 3-phosphoglycerate, its product, diffuse in and out of the pyrenoid. We also find that there is no major diffusional barrier to metabolic flux between the pyrenoid and stroma. Therefore, our computational approach represents a stepping stone towards understanding of microcompartmentalized CCM in other organisms. This thesis provides novel strategies to use genome-scale metabolic networks to predict and integrate metabolite concentrations. Therefore, the presented approaches represent an important step in broadening the applicability of large-scale metabolic models to a range of biotechnological and medical applications.
N2 - Der Stoffwechsel eines Organismus spiegelt den gesamten Phänotyp wieder, welcher durch genetische und umweltbedingte Veränderungen beeinflusst wird. Aufgrund der Komplexität des Stoffwechsels sind Modellierungsansätze, welche das ganzheitliches System betrachten, zu unverzichtbaren Instrumenten geworden, um neue Einblicke in biologische Funktionen zu erhalten. Insbesondere die Simulation und Analyse von Stoffwechselnetzwerken mithilfe von Constraint-basierten Modellierungsansätzen hat die Analyse von Stoffwechselflüssen erleichtert. Trotz kontinuierlicher Verbesserungen bei der Vorhersage des Reaktionsflusses durch ein System, sind Ansätze zur direkten Vorhersage von Metabolitkonzentrationen aus metabolischen Netzwerken kaum vorhanden. In dieser Arbeit stellen wir einen Ansatz vor, mit welchem Konzentrationsbereiche aus genomweiten metabolischen Netzwerken, die mit einer Massenwirkungskinetik ausgestattet sind, abgeleitet werden können. Die Ergebnisse zeigen einen molekularen Mechanismus auf, welcher der Steuerung von Konzentrationsbereichen für Komponenten in metabolischen Netzwerken zugrunde liegt. Eine erweiterte Version des Ansatzes kann verwendet werden, um Konzentrationsbereiche ohne Kenntnis der kinetischen Parameter vorherzusagen, vorausgesetzt, dass Messungen von Konzentrationen in einem Referenzzustand vorhanden sind. Wir zeigen, dass der Ansatz mit kinetischen und stöchiometrischen Stoffwechselmodellen von Organismen aus verschiedenen taxonomischen Reichen anwendbar ist. Indem wir die Vorhersagen von Konzentrationsbereichen im genomweiten Stoffwechselnetzwerk von Escherichia coli mit realen Datensätzen validieren, demonstrieren wir die Vorhersagekraft und die Grenzen des Ansatzes. Um Konzentrationsbereiche in anderen Spezies vorherzusagen, z.B. der Modellpflanzenspezies Arabidopsis thaliana, stützen wir uns auf Schätzungen der kinetischen Parameter (d.h. der katalytischen Enzymraten), da tatsächlich gemessene, pflanzenspezifische katalytische Enzymraten nur unzureichend dokumentiert sind. Unter Verwendung des Constraint-basierten Ansatzes von Davidi et al. zur Abschätzung der katalytischen Enzymraten erhalten wir Werte für 168 pflanzliche Enzyme. Der Ansatz hängt von quantitativen Proteomikdaten und Schätzungen des Reaktionsflusses ab, die aus einem Constraint-basierten Modell des Pflanzenblattmetabolismus unter Einbeziehung der maximalen Raten ausgewählter Enzyme, pflanzenspezifischen Einschränkungen des Flusses durch kanonische Pfade und Wachstumsmessungen aus Rosetten von Arabidopsis thaliana unter zehn Bedingungen erhalten wurden. Wir fanden einen niedrigen Grad an Sättigung der Pflanzenenzyme, der durch die Übereinstimmung zwischen den Konzentrationen von Nicotinamidadenindinukleotid, Adenosintriphosphat und Glycerinaldehyd-3-phosphat auf der Grundlage unserer maximalen in vivo katalytischen Raten und den verfügbaren quantitativen Metabolomikdaten gestützt wird. Daher zeigen unsere Ergebnisse, dass genomweite Schätzungen für pflanzenspezifische Enzymkatalyseraten möglich sind. Diese können nun leicht verwendet werden, um die Ressourcenzuweisung zu untersuchen und die Enzym- und Metabolitenkonzentrationen unter Verwendung neuerer Constraint-basierter Modellierungsansätze vorherzusagen. Constraint-basierte Methoden berücksichtigen kinetische Mechanismen und entsprechende Parameter nicht direkt. Daher wurden einige Methoden entwickelt, welche die Reaktionskinetik approximieren und systemumfassende kinetische Modelle zu parametrisieren. Wir präsentieren eine systembiologische Strategie zur Erstellung eines vollständig parametrisierten Modells von Chlamydomonas reinhardtii, welches die Mikrokompartimentierung im Chloroplaststroma berücksichtigt. Eukaryotische Algen besitzen ein Mikrokompartiment, den Pyrenoiden, der für den Kohlenstoffkonzentrationsmechanismus (KKM) unerlässlich ist und die Photosyntheseleistung verbessert. Die experimentelle Untersuchung der Auswirkungen der Mikrokompartimentierung auf Stoffwechselwege stellt eine Herausforderung dar. Daher verwenden wir unser Modell um die Kompartimentierung von Reaktionsflüssen durch den Calvin-Benson-Zyklus zwischen Pyrenoid und Stroma zu untersuchen. Unser Modell sagt voraus, dass Ribulose-1,5-Bisphosphat, das Substrat von Rubisco, und 3-Phosphoglycerat , das Produkt, in den Pyrenoid hinein und aus ihm heraus diffundieren. Weiter stellen wir fest, dass es keine wesentliche Diffusionsbarriere zwischen dem Pyrenoid und dem Stroma gibt. Somit bietet unser Ansatz eine Möglichkeit um ein Verständnis des mikrokompartimentierten KKM auch in anderen Organismen zu erlangen. Diese Dissertation zeigt neue Strategien um metabolische Netzwerke zur Vorhersage von Metabolitkonzentrationen zu nutzen und selbige zu integrieren. Daher stellen die Ansätze einen wichtigen Schritt zur Anwendbarkeit von genomweiten Stoffwechselmodellen auf eine Reihe von biotechnologischen und medizinischen Anwendungen dar.
KW - constraint-based modeling
KW - metabolism
KW - metabolic networks
Y1 - 2020
ER -
TY - JOUR
A1 - van Velzen, Ellen
T1 - Predator coexistence through emergent fitness equalization
JF - Ecology : a publication of the Ecological Society of America
N2 - The competitive exclusion principle is one of the oldest ideas in ecology and states that without additional self-limitation two predators cannot coexist on a single prey. The search for mechanisms allowing coexistence despite this has identified niche differentiation between predators as crucial: without this, coexistence requires the predators to have exactly the same R* values, which is considered impossible. However, this reasoning misses a critical point: predators' R* values are not static properties, but affected by defensive traits of their prey, which in turn can adapt in response to changes in predator densities. Here I show that this feedback between defense and predator dynamics enables stable predator coexistence without ecological niche differentiation. Instead, the mechanism driving coexistence is that prey adaptation causes defense to converge to the value where both predators have equal R* values ("fitness equalization"). This result is highly general, independent of specific model details, and applies to both rapid defense evolution and inducible defenses. It demonstrates the importance of considering long-standing ecological questions from an eco-evolutionary viewpoint, and showcases how the effects of adaptation can cascade through communities, driving diversity on higher trophic levels. These insights offer an important new perspective on coexistence theory.
KW - coexistence
KW - competition
KW - competitive exclusion
KW - defense
KW - eco-evolutionary feedbacks
KW - emergent facilitation
KW - predator
KW - prey
KW - dynamics
Y1 - 2020
U6 - https://doi.org/10.1002/ecy.2995
SN - 0012-9658
SN - 1939-9170
VL - 101
IS - 5
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Martin, Lidia
A1 - Dorjee, Binu
A1 - Groth, Detlef
A1 - Scheffler, Christiane
T1 - Positive influence of parental education on growth of children
BT - statistical analysis of correlation between social and nutritional
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger
N2 - In nature, dominance is often shown by body size; even in humans many studies report that social status is associated with body height. In today's society, educational status is an important factor for social classification. Since growing children do not have their own educational or social status, they are often affected by the status of their parents. Therefore, the question appears, whether parental educational status measurably affects the growth of a child. If so, is this explainable by the nutritional factors? To test this hypothesis, seven different Indian data sets where reexamined using the St. Nicolas House Analysis. The results show a direct association between parental education and body height (hSDS) of the child, but there was no influence of parental education on the nutritional status. We conclude that education has a direct effect on height that is not mediated via nutrition.
KW - parental educational status
KW - social classification
KW - body height
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1177
SN - 0003-5548
SN - 2363-7099
VL - 77
IS - 5
SP - 375
EP - 387
PB - Schweizerbart science publishers
CY - Stuttgart
ER -
TY - THES
A1 - Autenrieth, Marijke
T1 - Population genomics of two odontocetes in the North Atlantic and adjacent waters
BT - Evolutionary history and conservation implications
N2 - Due to continuously intensifying human usage of the marine environment worldwide ranging cetaceans face an increasing number of threats. Besides whaling, overfishing and by-catch, new technical developments increase the water and noise pollution, which can negatively affect marine species. Cetaceans are especially prone to these influences, being at the top of the food chain and therefore accumulating toxins and contaminants. Furthermore, they are extremely noise sensitive due to their highly developed hearing sense and echolocation ability. As a result, several cetacean species were brought to extinction during the last century or are now classified as critically endangered. This work focuses on two odontocetes. It applies and compares different molecular methods for inference of population status and adaptation, with implications for conservation. The worldwide distributed sperm whale (Physeter macrocephalus) shows a matrilineal population structure with predominant male dispersal. A recently stranded group of male sperm whales provided a unique opportunity to investigate male grouping for the first time. Based on the mitochondrial control region, I was able to infer that male bachelor groups comprise multiple matrilines, hence derive from different social groups, and that they represent the genetic variability of the entire North Atlantic. The harbor porpoise (Phocoena phocoena) occurs only in the northern hemisphere. By being small and occurring mostly in coastal habitats it is especially prone to human disturbance. Since some subspecies and subpopulations are critically endangered, it is important to generate and provide genetic markers with high resolution to facilitate population assignment and subsequent protection measurements. Here, I provide the first harbour porpoise whole genome, in high quality and including a draft annotation. Using it for mapping ddRAD seq data, I identify genome wide SNPs and, together with a fragment of the mitochondrial control region, inferred the population structure of its North Atlantic distribution range. The Belt Sea harbors a distinct subpopulation oppose to the North Atlantic, with a transition zone in the Kattegat. Within the North Atlantic I could detect subtle genetic differentiation between western (Canada-Iceland) and eastern (North Sea) regions, with support for a German North Sea breading ground around the Isle of Sylt. Further, I was able to detect six outlier loci which show isolation by distance across the investigated sampling areas. In employing different markers, I could show that single maker systems as well as genome wide data can unravel new information about population affinities of odontocetes. Genome wide data can facilitate investigation of adaptations and evolutionary history of the species and its populations. Moreover, they facilitate population genetic investigations, providing a high resolution, and hence allowing for detection of subtle population structuring especially important for highly mobile cetaceans.
N2 - Mit der immer stärker zunehmenden Nutzung des marinen Lebensraumes durch den Menschen, häufen sich auch die Bedrohungen, wie beispielsweise Lebensraumzerstörungen, denen Cetacea ausgesetzt sind. Die Folgen aus Walfang, Überfischung und Beifang, wie auch die stärkere Verschmutzung der Meere sowie die Zunahme des generellen Lärmpegels, haben negative Effekte auf eine Vielzahl mariner Arten. Cetacea sind besonders anfällig für diese Störungen, da sie einerseits am Ende der Nahrungskette stehen und somit besonders Schadstoffe, wie bspw. PBEs, in ihren Körpern akkumulieren und andererseits durch ihr hoch angepasstes Gehör äußerst sensibel gegenüber Geräuschstörungen sind. Im Laufe des letzten Jahrhunderts wurden einige marine Säugetiere bereits ausgerottet oder fast bis an den Rand des Aussterbens gebracht. Diese Arbeit konzentriert sich auf zwei Zahnwalarten, die in ihrer Biologie und Populationsstruktur sehr verschieden sind. Sie bieten die Möglichkeit, verschiedene Methoden der Naturschutz- und Populationsgenetik anzuwenden und zu vergleichen. Der weltweit verbreitete Pottwal ist matrilineal organisiert mit Weibchen, die in sozialen Gruppen in der Nähe des Äquators leben, und Männchen, die in kleinen Gruppen zu den Polen migrieren. Zum Jahresbeginn 2016 strandete eine Gruppe junger männlicher Pottwale entlang der Nordsee. Dieses Ereignis bot die einzigartige Chance, erstmals die genetische Zusammensetzung einer männlichen Pottwalgruppe zu untersuchen. Basierend auf der mitochondrialen Kontrollregion, konnte ich zeigen, dass sie von mehreren Matrilinien abstammen und in ihrer Gesamtheit die genetische Vielfalt der nordatlantischen Gesamtpopulation repräsentieren. Der Schweinswal ist innerhalb der nördlichen Hemisphäre weit verbreitet. Durch seine kleine Körpergrösse und die Präferenz für küstennahe Habitate ist er besonders anfällig gegenüber negativen anthropogenen Einflüssen. Da sowohl eine seiner Unterarten als auch einige Subpopulationen durch die IUCN als stark bedroht klassifiziert sind, ist es besonders wichtig die genetische Struktur dieser Art und ihrer Populationen zu erfassen und hochauflösende Markersysteme zu generieren, um verlässliche Informationen zum Status lokaler Populationen für weiterführende Naturschutzmaßnahmen bereitzustellen. In dieser Arbeit konnte ich die erste komplette Genomsequenz des Schweinwal in hoher Qualität bereitstellen und sie für die Analyse von ddRAD-Daten als Referenz nutzen. Mittles genomweit verteilter SNPs, sowie einem Abschnitt der mitochondrialen Kontrollregion zeigte sich, dass die Schweinswale in der Beltsee eine eigenständige Population bilden, mit einer Transitionszone zum Nord-Atlantik im Kattegat. Innerhalb des Nord-Atlantiks zeigten sich Unterschiede zwischen West (Kanada-Island) und Ost (Nordsee), sowie eine Abgrenzung deutscher Schweinswale um die Insel Sylt. Außerdem konnte ich sechs SNPs identifizieren, welche die populationsgenetische Auflösung im Nordatlantik und geographischen Distanz wiederspiegeln. Durch den Vergleich verschiedener Markersysteme konnte ich zeigen, dass sowohl einzelne Marker als auch genomweite Marker neue Erkenntnisse zu Populationsstrukturen und Anpassungen von Zahnwalen liefern. Durch die hohe Mobilität und den schwer zugänglichen Lebensraum mariner Säugetiere sind hochauflösende genetische Markersysteme der Schlüssel für ein besseres Verständnis und den Schutz dieser Arten.
KW - genomics
KW - population genetics
KW - conservation
KW - evolution
KW - whole genome
KW - toothed whales
KW - Genomik
KW - Populationsgenetik
KW - Naturschutz
KW - Evolution
KW - Zahnwale
Y1 - 2020
ER -
TY - JOUR
A1 - Liu, Yue
A1 - Gould, Oliver E. C.
A1 - Rudolph, Tobias
A1 - Fang, Liang
A1 - Kratz, Karl
A1 - Lendlein, Andreas
T1 - Polymeric microcuboids programmable for temperature-memory
JF - Macromolecular materials and engineering
N2 - Microobjects with programmable mechanical functionality are highly desirable for the creation of flexible electronics, sensors, and microfluidic systems, where fabrication/programming and quantification methods are required to fully control and implement dynamic physical behavior. Here, programmable microcuboids with defined geometries are prepared by a template-based method from crosslinked poly[ethylene-co-(vinyl acetate)] elastomers. These microobjects could be programmed to exhibit a temperature-memory effect or a shape-memory polymer actuation capability. Switching temperaturesT(sw)during shape recovery of 55 +/- 2, 68 +/- 2, 80 +/- 2, and 86 +/- 2 degrees C are achieved by tuning programming temperatures to 55, 70, 85, and 100 degrees C, respectively. Actuation is achieved with a reversible strain of 2.9 +/- 0.2% to 6.7 +/- 0.1%, whereby greater compression ratios and higher separation temperatures induce a more pronounced actuation. Micro-geometry change is quantified using optical microscopy and atomic force microscopy. The realization and quantification of microparticles, capable of a tunable temperature responsive shape-change or reversible actuation, represent a key development in the creation of soft microscale devices for drug delivery or microrobotics.
KW - actuation
KW - atomic force microscopy
KW - biomaterials
KW - microparticles
KW - shape-memory polymers
Y1 - 2020
U6 - https://doi.org/10.1002/mame.202000333
SN - 1438-7492
SN - 1439-2054
VL - 305
IS - 10
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Behl, Marc
A1 - Razzaq, Muhammad Yasar
A1 - Mazurek-Budzynska, Magdalena
A1 - Lendlein, Andreas
T1 - Polyetheresterurethane based porous scaffolds with tailorable architectures by supercritical CO2 foaming
JF - MRS advances
N2 - Porous three-dimensional (3D) scaffolds are promising treatment options in regenerative medicine. Supercritical and dense-phase fluid technologies provide an attractive alternative to solvent-based scaffold fabrication methods. In this work, we report on the fabrication of poly-etheresterurethane (PPDO-PCL) based porous scaffolds with tailorable pore size, porosity, and pore interconnectivity by using supercritical CO2(scCO(2)) fluid-foaming. The influence of the processing parameters such as soaking time, soaking temperature and depressurization on porosity, pore size, and interconnectivity of the foams were investigated. The average pore diameter could be varied between 100-800 mu m along with a porosity in the range from (19 +/- 3 to 61 +/- 6)% and interconnectivity of up to 82%. To demonstrate their applicability as scaffold materials, selected foams were sterilized via ethylene oxide sterilization. They showed negligible cytotoxicity in tests according to DIN EN ISO 10993-5 and 10993-12 using L929 cells. The study demonstrated that the pore size, porosity and the interconnectivity of this multi-phase semicrystalline polymer could be tailored by careful control of the processing parameters during the scCO(2)foaming process. In this way, PPDO-PCL scaffolds with high porosity and interconnectivity are potential candidate materials for regenerative treatment options.
Y1 - 2020
U6 - https://doi.org/10.1557/adv.2020.345
SN - 2059-8521
VL - 5
IS - 45
SP - 2317
EP - 2330
PB - Cambridge University Press
CY - New York, NY
ER -
TY - JOUR
A1 - Niere, Oliver
A1 - Spannemann, Lisa
A1 - Stenzel, Patrick
A1 - Bogin, Barry
A1 - Hermanussen, Michael
A1 - Scheffler, Christiane
T1 - Plasticity of human growth
BT - a systematic review on psychosocial factors influencing growth
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie
N2 - Background:
This systematic review aimed at collecting, analyzing and summarizing scientific studies focusing on psychosocial factors that influence linear growth among humans.
Methods:
The online database "PubMed" was used in order to acquire suitable scientific studies. These studies were evaluated based on clearly defined criteria that determine whether a study was to be excluded or included in the literature review. In the end, a total sum of 36 studies remained, which were carefully analyzed and used to generate an overview of the association between psychosocial factors and linear growth.
Results:
In the 36 reviewed studies, different social and psychological factors, such as socioeconomic status, parental education or emotional deprivation were set in relation to physical growth among humans. The studies were listed and summarized, depending on the investigated psychosocial factor. A clear association between psychosocial factors and growth could be observed in most of the reviewed studies. Discussion: Based on the results of the reviewed studies it could be concluded that the regulation of linear growth is also subject to different psychosocial factors. The way in which the developing human and the specific social environment interact seemed to have a major impact on linear growth. Statusspecific stress was discussed as one possible explanation for the regulating mechanism of human linear growth.
KW - linear growth
KW - final body height
KW - regulation
KW - psychosocial factors
KW - social factors
KW - psychological factors
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1223
SN - 0003-5548
SN - 2363-7099
VL - 77
IS - 5
SP - 431
EP - 443
PB - Schweizerbart
CY - Stuttgart
ER -
TY - JOUR
A1 - Halilbasic, Emina
A1 - Fuerst, Elisabeth
A1 - Heiden, Denise
A1 - Japtok, Lukasz
A1 - Diesner, Susanne C.
A1 - Trauner, Michael
A1 - Kulu, Askin
A1 - Jaksch, Peter
A1 - Hoetzenecker, Konrad
A1 - Kleuser, Burkhard
A1 - Kazemi-Shirazi, Lili
A1 - Untersmayr, Eva
T1 - Plasma levels of the bioactive sphingolipid metabolite S1P in adult cystic fibrosis patients
BT - potential target for immunonutrition?
JF - Nutrients
N2 - Recent research has linked sphingolipid (SL) metabolism with cystic fibrosis transmembrane conductance regulator (CFTR) activity, affecting bioactive lipid mediator sphingosine-1-phosphate (S1P). We hypothesize that loss of CFTR function in cystic fibrosis (CF) patients influenced plasma S1P levels. Total and unbound plasma S1P levels were measured in 20 lung-transplanted adult CF patients and 20 healthy controls by mass spectrometry and enzyme-linked immunosorbent assay (ELISA). S1P levels were correlated with CFTR genotype, routine laboratory parameters, lung function and pathogen colonization, and clinical symptoms. Compared to controls, CF patients showed lower unbound plasma S1P, whereas total S1P levels did not differ. A positive correlation of total and unbound S1P levels was found in healthy controls, but not in CF patients. Higher unbound S1P levels were measured in Delta F508-homozygous compared to Delta F508-heterozygous CF patients (p = 0.038), accompanied by higher levels of HDL in Delta F508-heterozygous patients. Gastrointestinal symptoms were more common in Delta F508 heterozygotes compared to Delta F508 homozygotes. This is the first clinical study linking plasma S1P levels with CFTR function and clinical presentation in adult CF patients. Given the emerging role of immunonutrition in CF, our study might pave the way for using S1P as a novel biomarker and nutritional target in CF.
KW - sphingolipids
KW - sphingosine-1-phosphate
KW - intestine
KW - high density
KW - lipoproteins
KW - cystic fibrosis
KW - Delta F508 mutation
KW - immunonutrition
Y1 - 2020
U6 - https://doi.org/10.3390/nu12030765
SN - 2072-6643
VL - 12
IS - 3
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Marzetz, Vanessa
A1 - Spijkerman, Elly
A1 - Striebel, Maren
A1 - Wacker, Alexander
T1 - Phytoplankton community responses to interactions between light intensity, light variations, and phosphorus supply
JF - Frontiers in Environmental Science
N2 - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
KW - phytoplankton communities
KW - light variability
KW - photosynthetic rate
KW - climate change
KW - resource competition
KW - light intensity (irradiance)
KW - pigment composition
KW - nutrient supply
Y1 - 2020
U6 - https://doi.org/10.3389/fenvs.2020.539733
SN - 2296-665X
VL - 8
PB - Frontiers Media
CY - Lausanne
ER -
TY - GEN
A1 - Marzetz, Vanessa
A1 - Spijkerman, Elly
A1 - Striebel, Maren
A1 - Wacker, Alexander
T1 - Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1109
KW - phytoplankton communities
KW - light variability
KW - photosynthetic rate
KW - climate change
KW - resource competition
KW - light intensity (irradiance)
KW - pigment composition
KW - nutrient supply
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491041
SN - 1866-8372
IS - 1109
ER -
TY - JOUR
A1 - Marzetz, Vanessa
A1 - Spijkerman, Elly
A1 - Striebel, Maren
A1 - Wacker, Alexander
T1 - Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply
JF - Frontiers in Environmental Science
N2 - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
KW - phytoplankton communities
KW - light variability
KW - photosynthetic rate
KW - climate change
KW - resource competition
KW - light intensity (irradiance)
KW - pigment composition
KW - nutrient supply
Y1 - 2020
U6 - https://doi.org/10.3389/fenvs.2020.539733
SN - 2296-665X
VL - 8
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Moreno Curtidor, Catalina
A1 - Annunziata, Maria Grazia
A1 - Gupta, Saurabh
A1 - Apelt, Federico
A1 - Richard, Sarah Isabel
A1 - Kragler, Friedrich
A1 - Müller-Röber, Bernd
A1 - Olas, Justyna Jadwiga
T1 - Physiological profiling of embryos and dormant seeds in two Arabidopsis accessions reveals a metabolic switch in carbon reserve accumulation
JF - Frontiers in plant science
N2 - In flowering plants, sugars act as carbon sources providing energy for developing embryos and seeds. Although most studies focus on carbon metabolism in whole seeds, knowledge about how particular sugars contribute to the developmental transitions during embryogenesis is scarce. To develop a quantitative understanding of how carbon composition changes during embryo development, and to determine how sugar status contributes to final seed or embryo size, we performed metabolic profiling of hand-dissected embryos at late torpedo and mature stages, and dormant seeds, in two Arabidopsis thaliana accessions with medium [Columbia-0 (Col-0)] and large [Burren-0 (Bur-0)] seed sizes, respectively. Our results show that, in both accessions, metabolite profiles of embryos largely differ from those of dormant seeds. We found that developmental transitions from torpedo to mature embryos, and further to dormant seeds, are associated with major metabolic switches in carbon reserve accumulation. While glucose, sucrose, and starch predominantly accumulated during seed dormancy, fructose levels were strongly elevated in mature embryos. Interestingly, Bur-0 seeds contain larger mature embryos than Col-0 seeds. Fructose and starch were accumulated to significantly higher levels in mature Bur-0 than Col-0 embryos, suggesting that they contribute to the enlarged mature Bur-0 embryos. Furthermore, we found that Bur-0 embryos accumulated a higher level of sucrose compared to hexose sugars and that changes in sucrose metabolism are mediated by sucrose synthase (SUS), with SUS genes acting non-redundantly, and in a tissue-specific manner to utilize sucrose during late embryogenesis.
KW - carbon
KW - embryo development
KW - hexoses
KW - metabolites
KW - sucrose
KW - synthase
Y1 - 2020
U6 - https://doi.org/10.3389/fpls.2020.588433
SN - 1664-462X
VL - 11
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - De Cahsan, Binia
A1 - Nagel, Rebecca
A1 - Schedina, Ina-Maria
A1 - King, James J.
A1 - Bianco, Pier G.
A1 - Tiedemann, Ralph
A1 - Ketmaier, Valerio
T1 - Phylogeography of the European brook lamprey (Lampetra planeri) and the European river lamprey (Lampetra fluviatilis) species pair based on mitochondrial data
JF - Journal of fish biology
N2 - The European river lamprey Lampetra fluviatilis and the European brook lamprey Lampetra planeri (Block 1784) are classified as a paired species, characterized by notably different life histories but morphological similarities. Previous work has further shown limited genetic differentiation between these two species at the mitochondrial DNA level. Here, we expand on this previous work, which focused on lamprey species from the Iberian Peninsula in the south and mainland Europe in the north, by sequencing three mitochondrial marker regions of Lampetra individuals from five river systems in Ireland and five in southern Italy. Our results corroborate the previously identified pattern of genetic diversity for the species pair. We also show significant genetic differentiation between Irish and mainland European lamprey populations, suggesting another ichthyogeographic district distinct from those previously defined. Finally, our results stress the importance of southern Italian L. planeri populations, which maintain several private alleles and notable genetic diversity.
KW - European lamprey
KW - Lampetra
KW - paired species
KW - phylogeography
KW - population
KW - structure
Y1 - 2020
U6 - https://doi.org/10.1111/jfb.14279
SN - 0022-1112
SN - 1095-8649
VL - 96
IS - 4
SP - 905
EP - 912
PB - Wiley-Blackwell
CY - Oxford [u.a.]
ER -
TY - JOUR
A1 - Potts, Jonathan R.
A1 - Schlägel, Ulrike E.
T1 - Parametrizing diffusion-taxis equations from animal movement trajectories using step selection analysis
JF - Methods in ecology and evolution : an official journal of the British Ecological Society
N2 - Mathematical analysis of partial differential equations (PDEs) has led to many insights regarding the effect of organism movements on spatial population dynamics. However, their use has mainly been confined to the community of mathematical biologists, with less attention from statistical and empirical ecologists. We conjecture that this is principally due to the inherent difficulties in fitting PDEs to data. To help remedy this situation, in the context of movement ecology, we show how the popular technique of step selection analysis (SSA) can be used to parametrize a class of PDEs, calleddiffusion-taxismodels, from an animal's trajectory. We examine the accuracy of our technique on simulated data, then demonstrate the utility of diffusion-taxis models in two ways. First, for non-interacting animals, we derive the steady-state utilization distribution in a closed analytic form. Second, we give a recipe for deriving spatial pattern formation properties that emerge from interacting animals: specifically, do those interactions cause heterogeneous spatial distributions to emerge and if so, do these distributions oscillate at short times or emerge without oscillations? The second question is applied to data on concurrently tracked bank volesMyodes glareolus. Our results show that SSA can accurately parametrize diffusion-taxis equations from location data, providing the frequency of the data is not too low. We show that the steady-state distribution of our diffusion-taxis model, where it is derived, has an identical functional form to the utilization distribution given by resource selection analysis (RSA), thus formally linking (fine scale) SSA with (broad scale) RSA. For the bank vole data, we show how our SSA-PDE approach can give predictions regarding the spatial aggregation and segregation of different individuals, which are difficult to predict purely by examining results of SSA. Our methods provide a user-friendly way into the world of PDEs, via a well-used statistical technique, which should lead to tighter links between the findings of mathematical ecology and observations from empirical ecology. By providing a non-speculative link between observed movement behaviours and space use patterns on larger spatio-temporal scales, our findings will also aid integration of movement ecology into understanding spatial species distributions.
KW - advection-diffusion
KW - animal movement
KW - home range
KW - movement ecology
KW - partial differential equations
KW - resource selection
KW - step selection
KW - taxis
Y1 - 2020
U6 - https://doi.org/10.1111/2041-210X.13406
SN - 2041-210X
VL - 11
IS - 9
SP - 1092
EP - 1105
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Korniienko, Yevheniia
A1 - Tiedemann, Ralph
A1 - Vater, Marianne
A1 - Kirschbaum, Frank
T1 - Ontogeny of the electric organ discharge and of the papillae of the electrocytes in the weakly electric fish Campylomormyrus rhynchophorus (Teleostei: Mormyridae)
JF - The journal of comparative neurology
N2 - The electric organ of the mormyrid weakly electric fish,Campylomormyrus rhynchophorus(Boulenger, 1898), undergoes changes in both the electric organ discharge (EOD) and the light and electron microscopic morphology as the fish mature from the juvenile to the adult form. Of particular interest was the appearance of papillae, surface specializations of the uninnervated anterior face of the electrocyte, which have been hypothesized to increase the duration of the EOD. In a 24.5 mm long juvenile the adult electric organ (EO) was not yet functional, and the electrocytes lacked papillae. A 40 mm long juvenile, which produced a short biphasic EOD of 1.3 ms duration, shows small papillae (average area 136 mu m(2)). In contrast, the EOD of a 79 mm long juvenile was triphasic. The large increase in duration of the EOD to 23.2 ms was accompanied by a small change in size of the papillae (average area 159 mu m(2)). Similarly, a 150 mm long adult produced a triphasic EOD of comparable duration to the younger stage (24.7 ms) but featured a prominent increase in size of the papillae (average area 402 mu m(2)). Thus, there was no linear correlation between EOD duration and papillary size. The most prominent ultrastructural change was at the level of the myofilaments, which regularly extended into the papillae, only in the oldest specimen-probably serving a supporting function. Physiological mechanisms, like gene expression levels, as demonstrated in someCampylomormyrusspecies, might be more important concerning the duration of the EOD.
KW - Campylomormyrus
KW - electric organ discharge
KW - electrocyte ontogeny
KW - electrocyte ultrastructure
KW - papillae
Y1 - 2020
U6 - https://doi.org/10.1002/cne.25003
SN - 0021-9967
SN - 1096-9861
VL - 529
IS - 5
SP - 1052
EP - 1065
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Nguyen, Manh Duy Linh
A1 - Mamonekene, Victor
A1 - Vater, Marianne
A1 - Bartsch, Peter
A1 - Tiedemann, Ralph
A1 - Kirschbaum, Frank
T1 - Ontogeny of electric organ and electric organ discharge in Campylomormyrus rhynchophorus (Teleostei: Mormyridae)
JF - Journal of comparative physiology; A, Neuroethology, sensory, neural, and behavioral physiology
N2 - The aim of this study was a longitudinal description of the ontogeny of the adult electric organ of Campylomormyrus rhynchophorus which produces as adult an electric organ discharge of very long duration (ca. 25 ms). We could indeed show (for the first time in a mormyrid fish) that the electric organ discharge which is first produced early during ontogeny in 33-mm-long juveniles is much shorter in duration and has a different shape than the electric organ discharge in 15-cm-long adults. The change from this juvenile electric organ discharges into the adult electric organ discharge takes at least a year. The increase in electric organ discharge duration could be causally linked to the development of surface evaginations, papillae, at the rostral face of the electrocyte which are recognizable for the first time in 65-mm-long juveniles and are most prominent at the periphery of the electrocyte.
KW - Weakly electric fish
KW - Development
KW - Electric organ discharge
KW - Electric
KW - organ
KW - Electrocyte features
Y1 - 2020
U6 - https://doi.org/10.1007/s00359-020-01411-z
SN - 0340-7594
SN - 1432-1351
VL - 206
IS - 3
SP - 453
EP - 466
PB - Springer
CY - Berlin ; Heidelberg
ER -
TY - GEN
A1 - Dammhahn, Melanie
A1 - Mazza, Valeria
A1 - Schirmer, Annika
A1 - Göttsche, Claudia
A1 - Eccard, Jana
T1 - Of city and village mice
BT - behavioural adjustments of striped field mice to urban environments
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1007
KW - personality-traits
KW - apodemus-agrarius
KW - exploratory-behavior
KW - fitness consequences
KW - individual variation
KW - avian personalities
KW - animal personality
KW - rural populations
KW - natural-selection
KW - natal dispersal
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-480063
SN - 1866-8372
IS - 1007
ER -
TY - JOUR
A1 - Dammhahn, Melanie
A1 - Mazza, Valeria
A1 - Schirmer, Annika
A1 - Göttsche, Claudia
A1 - Eccard, Jana
T1 - Of city and village mice
BT - behavioural adjustments of striped field mice to urban environments
JF - Scientific Reports
N2 - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.
KW - personality-traits
KW - apodemus-agrarius
KW - exploratory-behavior
KW - fitness consequences
KW - individual variation
KW - avian personalities
KW - animal personality
KW - rural populations
KW - natural-selection
KW - natal dispersal
Y1 - 2020
U6 - https://doi.org/10.1038/s41598-020-69998-6
SN - 2045-2322
VL - 10
PB - Macmillan Publishers Limited
CY - London
ER -
TY - JOUR
A1 - Riebold, Diana
A1 - Russow, Kati
A1 - Schlegel, Mathias
A1 - Wollny, Theres
A1 - Thiel, Joerg
A1 - Freise, Jona
A1 - Hueppop, Ommo
A1 - Eccard, Jana
A1 - Plenge-Boenig, Anita
A1 - Loebermann, Micha
A1 - Ulrich, Rainer Günter
A1 - Klammt, Sebastian
A1 - Mettenleiter, Thomas Christoph
A1 - Reisinger, Emil Christian
T1 - Occurrence of gastrointestinal parasites in small mammals from Germany
JF - Vector borne and zoonotic diseases
N2 - An increase in zoonotic infections in humans in recent years has led to a high level of public interest. However, the extent of infestation of free-living small mammals with pathogens and especially parasites is not well understood. This pilot study was carried out within the framework of the "Rodent-borne pathogens" network to identify zoonotic parasites in small mammals in Germany. From 2008 to 2009, 111 small mammals of 8 rodent and 5 insectivore species were collected. Feces and intestine samples from every mammal were examined microscopically for the presence of intestinal parasites by using Telemann concentration for worm eggs, Kinyoun staining for coccidia, and Heidenhain staining for other protozoa. Adult helminths were additionally stained with carmine acid for species determination. Eleven different helminth species, five coccidians, and three other protozoa species were detected. Simultaneous infection of one host by different helminths was common. Hymenolepis spp. (20.7%) were the most common zoonotic helminths in the investigated hosts. Coccidia, including Eimeria spp. (30.6%), Cryptosporidium spp. (17.1%), and Sarcocystis spp. (17.1%), were present in 40.5% of the feces samples of small mammals. Protozoa, such as Giardia spp. and amoebae, were rarely detected, most likely because of the repeated freeze-thawing of the samples during preparation. The zoonotic pathogens detected in this pilot study may be potentially transmitted to humans by drinking water, smear infection, and airborne transmission.
KW - parasites
KW - rodents
KW - insectivores
KW - Hymenolepis
KW - Germany
Y1 - 2020
U6 - https://doi.org/10.1089/vbz.2019.2457
SN - 1530-3667
SN - 1557-7759
VL - 20
IS - 2
SP - 125
EP - 133
PB - Liebert
CY - New Rochelle
ER -
TY - JOUR
A1 - Webber, Heidi
A1 - Lischeid, Gunnar
A1 - Sommer, Michael
A1 - Finger, Robert
A1 - Nendel, Claas
A1 - Gaiser, Thomas
A1 - Ewert, Frank
T1 - No perfect storm for crop yield failure in Germany
JF - Environmental research letters
N2 - Large-scale crop yield failures are increasingly associated with food price spikes and food insecurity and are a large source of income risk for farmers. While the evidence linking extreme weather to yield failures is clear, consensus on the broader set of weather drivers and conditions responsible for recent yield failures is lacking. We investigate this for the case of four major crops in Germany over the past 20 years using a combination of machine learning and process-based modelling. Our results confirm that years associated with widespread yield failures across crops were generally associated with severe drought, such as in 2018 and to a lesser extent 2003. However, for years with more localized yield failures and large differences in spatial patterns of yield failures between crops, no single driver or combination of drivers was identified. Relatively large residuals of unexplained variation likely indicate the importance of non-weather related factors, such as management (pest, weed and nutrient management and possible interactions with weather) explaining yield failures. Models to inform adaptation planning at farm, market or policy levels are here suggested to require consideration of cumulative resource capture and use, as well as effects of extreme events, the latter largely missing in process-based models. However, increasingly novel combinations of weather events under climate change may limit the extent to which data driven methods can replace process-based models in risk assessments.
KW - crop yield failure
KW - extreme events
KW - support vector machine
KW - process-based crop model
KW - Germany
Y1 - 2020
U6 - https://doi.org/10.1088/1748-9326/aba2a4
SN - 1748-9326
VL - 15
IS - 10
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Maqsood, Arusa
A1 - Naumenko, Daniel J.
A1 - Hermanussen, Michael
A1 - Scheffler, Christiane
A1 - Groth, Detlef
T1 - No correlation between short term weight gain and lower leg length gain in healthy German children
JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie
N2 - Background:
Length-for-age is considered the indicator of choice in monitoring the long-term impact of chronic nutritional deficiency. Aim: We hypothesized that short term increments of body weight cross-correlate with increments of the lower leg length.
Sample and methods:
We re-analyzed the association between weekly measurements of weight and of lower leg length in 34 healthy German children, aged 2.9-15.9 years. The data are a subset of measurements originally published in 1988 (Hermanussen et al. 1988a). As the growth measurements were often not equally spaced in time due to interposed holidays and illness, the incremental rates for weight and lower leg length were smoothed using spline functions. Autocorrelation and cross-correlation functions were calculated for weight increments and lower leg length increments.
Results:
Height and weight increments are pulsatile. Autocorrelations indicated that mini growth spurts occur at irregular intervals. Lack of cross-correlations between weight and lower leg length indicated that mini spurts in weight gain do not coincide with mini spurts in length gain even when considering lag times of up to 10 weeks. Short term changes of weight gain and lower leg length gain in healthy children show no temporal association.
KW - knemometry
KW - short term growth
KW - mini growth spurts
KW - lower leg length
Y1 - 2020
U6 - https://doi.org/10.1127/anthranz/2020/1237
SN - 0003-5548
SN - 2363-7099
VL - 77
IS - 5
SP - 399
EP - 403
PB - Schweizerbart
CY - Stuttgart
ER -
TY - THES
A1 - Lauterbach, Lars
T1 - NiFe hydrogenases
BT - Exploitation of biological H2 conversion in the presence of O2 for biotechnology
Y1 - 2020
ER -
TY - JOUR
A1 - Gubelit, Yulia I.
A1 - Grossart, Hans-Peter
T1 - New Methods, New Concepts
BT - What Can Be Applied to Freshwater Periphyton?
JF - Frontiers in Microbiology
N2 - Microbial interactions play an essential role in aquatic ecosystems and are of the great interest for both marine and freshwater ecologists. Recent development of new technologies and methods allowed to reveal many functional mechanisms and create new concepts. Yet, many fundamental aspects of microbial interactions have been almost exclusively studied for marine pelagic and benthic ecosystems. These studies resulted in a formulation of the Black Queen Hypothesis, a development of the phycosphere concept for pelagic communities, and a realization of microbial communication as a key mechanism for microbial interactions. In freshwater ecosystems, especially for periphyton communities, studies focus mainly on physiology, biodiversity, biological indication, and assessment, but the many aspects of microbial interactions are neglected to a large extent. Since periphyton plays a great role for aquatic nutrient cycling, provides the basis for water purification, and can be regarded as a hotspot of microbial biodiversity, we highlight that more in-depth studies on microbial interactions in periphyton are needed to improve our understanding on functioning of freshwater ecosystems. In this paper we first present an overview on recent concepts (e.g., the “Black Queen Hypothesis”) derived from state-of-the-art OMICS methods including metagenomics, metatranscriptomics, and metabolomics. We then point to the avenues how these methods can be applied for future studies on biodiversity and the ecological role of freshwater periphyton, a yet largely neglected component of many freshwater ecosystems.
KW - freshwater
KW - lake periphyton
KW - microbial interactions
KW - Black Queen Hypothesis
KW - OMICs tools
Y1 - 2020
U6 - https://doi.org/10.3389/fmicb.2020.01275
SN - 1664-302X
VL - 11
PB - Frontiers Media
CY - Lausanne
ER -
TY - GEN
A1 - Gubelit, Yulia I.
A1 - Grossart, Hans-Peter
T1 - New Methods, New Concepts
BT - What Can Be Applied to Freshwater Periphyton?
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Microbial interactions play an essential role in aquatic ecosystems and are of the great interest for both marine and freshwater ecologists. Recent development of new technologies and methods allowed to reveal many functional mechanisms and create new concepts. Yet, many fundamental aspects of microbial interactions have been almost exclusively studied for marine pelagic and benthic ecosystems. These studies resulted in a formulation of the Black Queen Hypothesis, a development of the phycosphere concept for pelagic communities, and a realization of microbial communication as a key mechanism for microbial interactions. In freshwater ecosystems, especially for periphyton communities, studies focus mainly on physiology, biodiversity, biological indication, and assessment, but the many aspects of microbial interactions are neglected to a large extent. Since periphyton plays a great role for aquatic nutrient cycling, provides the basis for water purification, and can be regarded as a hotspot of microbial biodiversity, we highlight that more in-depth studies on microbial interactions in periphyton are needed to improve our understanding on functioning of freshwater ecosystems. In this paper we first present an overview on recent concepts (e.g., the “Black Queen Hypothesis”) derived from state-of-the-art OMICS methods including metagenomics, metatranscriptomics, and metabolomics. We then point to the avenues how these methods can be applied for future studies on biodiversity and the ecological role of freshwater periphyton, a yet largely neglected component of many freshwater ecosystems.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 969
KW - freshwater
KW - lake periphyton
KW - microbial interactions
KW - Black Queen Hypothesis
KW - OMICs tools
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474286
SN - 1866-8372
IS - 969
ER -
TY - JOUR
A1 - Schirmer, Annika
A1 - Hoffmann, Julia
A1 - Eccard, Jana
A1 - Dammhahn, Melanie
T1 - My niche
BT - individual spatial niche specialization affects within- and between-species interactions
JF - Proceedings of the Royal Society of London : B, Biological sciences
N2 - Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species (Myodes glareolus, Apodemus agrarius). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture-mark- recapture (n = 126) and automated VHF telemetry (n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity.
KW - animal personality
KW - competition
KW - individual niche specialization
KW - movement ecology
KW - coexistence
KW - small mammals
Y1 - 2020
U6 - https://doi.org/10.1098/rspb.2019.2211
SN - 0962-8452
SN - 1471-2954
VL - 287
IS - 1918
PB - Royal Society
CY - London
ER -
TY - GEN
A1 - Moradian, Hanieh
A1 - Roch, Toralf
A1 - Lendlein, Andreas
A1 - Gossen, Manfred
T1 - mRNA transfection-induced activation of primary human monocytes and macrophages
BT - Dependence on carrier system and nucleotide modifcation
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Monocytes and macrophages are key players in maintaining immune homeostasis. Identifying strategies to manipulate their functions via gene delivery is thus of great interest for immunological research and biomedical applications. We set out to establish conditions for mRNA transfection in hard-to-transfect primary human monocytes and monocyte-derived macrophages due to the great potential of gene expression from in vitro transcribed mRNA for modulating cell phenotypes. mRNA doses, nucleotide modifications, and different carriers were systematically explored in order to optimize high mRNA transfer rates while minimizing cell stress and immune activation. We selected three commercially available mRNA transfection reagents including liposome and polymer-based formulations, covering different application spectra. Our results demonstrate that liposomal reagents can particularly combine high gene transfer rates with only moderate immune cell activation. For the latter, use of specific nucleotide modifications proved essential. In addition to improving efficacy of gene transfer, our findings address discrete aspects of innate immune activation using cytokine and surface marker expression, as well as cell viability as key readouts to judge overall transfection efficiency. The impact of this study goes beyond optimizing transfection conditions for immune cells, by providing a framework for assessing new gene carrier systems for monocyte and macrophage, tailored to specific applications.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1403
KW - sirna transfection
KW - mediated delivery
KW - gene delivery
KW - efficient
KW - immunogenicity
KW - lipoplexes
KW - cells
KW - therapeutics
KW - polarization
KW - pathways
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515694
SN - 1866-8372
IS - 1
ER -
TY - JOUR
A1 - Moradian, Hanieh
A1 - Roch, Toralf
A1 - Lendlein, Andreas
A1 - Gossen, Manfred
T1 - mRNA transfection-induced activation of primary human monocytes and macrophages
BT - Dependence on carrier system and nucleotide modifcation
JF - Scientific reports
N2 - Monocytes and macrophages are key players in maintaining immune homeostasis. Identifying strategies to manipulate their functions via gene delivery is thus of great interest for immunological research and biomedical applications. We set out to establish conditions for mRNA transfection in hard-to-transfect primary human monocytes and monocyte-derived macrophages due to the great potential of gene expression from in vitro transcribed mRNA for modulating cell phenotypes. mRNA doses, nucleotide modifications, and different carriers were systematically explored in order to optimize high mRNA transfer rates while minimizing cell stress and immune activation. We selected three commercially available mRNA transfection reagents including liposome and polymer-based formulations, covering different application spectra. Our results demonstrate that liposomal reagents can particularly combine high gene transfer rates with only moderate immune cell activation. For the latter, use of specific nucleotide modifications proved essential. In addition to improving efficacy of gene transfer, our findings address discrete aspects of innate immune activation using cytokine and surface marker expression, as well as cell viability as key readouts to judge overall transfection efficiency. The impact of this study goes beyond optimizing transfection conditions for immune cells, by providing a framework for assessing new gene carrier systems for monocyte and macrophage, tailored to specific applications.
KW - sirna transfection
KW - mediated delivery
KW - gene delivery
KW - efficient
KW - immunogenicity
KW - lipoplexes
KW - cells
KW - therapeutics
KW - polarization
KW - pathways
Y1 - 2020
U6 - https://doi.org/10.1038/s41598-020-60506-4
SN - 2045-2322
VL - 10
IS - 1
SP - 1
EP - 15
PB - Springer Nature
CY - London
ER -
TY - THES
A1 - Alirezaeizanjani, Zahra
T1 - Movement strategies of a multi-mode bacterial swimmer
N2 - Bacteria are one of the most widespread kinds of microorganisms that play essential roles in many biological and ecological processes. Bacteria live either as independent individuals or in organized communities. At the level of single cells, interactions between bacteria, their neighbors, and the surrounding physical and chemical environment are the foundations of microbial processes. Modern microscopy imaging techniques provide attractive and promising means to study the impact of these interactions on the dynamics of bacteria. The aim of this dissertation is to deepen our understanding four fundamental bacterial processes – single-cell motility, chemotaxis, bacterial interactions with environmental constraints, and their communication with neighbors – through a live cell imaging technique. By exploring these processes, we expanded our knowledge on so far unexplained mechanisms of bacterial interactions.
Firstly, we studied the motility of the soil bacterium Pseudomonas putida (P. putida), which swims through flagella propulsion, and has a complex, multi-mode swimming tactic. It was recently reported that P. putida exhibits several distinct swimming modes – the flagella can push and pull the cell body or wrap around it. Using a new combined phase-contrast and fluorescence imaging set-up, the swimming mode (push, pull, or wrapped) of each run phase was automatically recorded, which provided the full swimming statistics of the multi-mode swimmer. Furthermore, the investigation of cell interactions with a solid boundary illustrated an asymmetry for the different swimming modes; in contrast to the push and pull modes, the curvature of runs in wrapped mode was not affected by the solid boundary. This finding suggested that having a multi-mode swimming strategy may provide further versatility to react to environmental constraints.
Then we determined how P. putida navigates toward chemoattractants, i.e. its chemotaxis strategies. We found that individual run modes show distinct chemotactic responses in nutrition gradients. In particular, P. putida cells exhibited an asymmetry in their chemotactic responsiveness; the wrapped mode (slow swimming mode) was affected by the chemoattractant, whereas the push mode (fast swimming mode) was not. These results can be seen as a starting point to understand more complex chemotaxis strategies of multi-mode swimmers going beyond the well-known paradigm of Escherichia coli, that exhibits only one swimming mode.
Finally we considered the cell dynamics in a dense population. Besides physical interactions with their neighbors, cells communicate their activities and orchestrate their population behaviors via quorum-sensing. Molecules that are secreted to the surrounding by the bacterial cells, act as signals and regulate the cell population behaviour. We studied P. putida’s motility in a dense population by exposing the cells to environments with different concentrations of chemical signals. We found that higher amounts of chemical signals in the surrounding influenced the single-cell behaviourr, suggesting that cell-cell communications may also affect the flagellar dynamics.
In summary, this dissertation studies the dynamics of a bacterium with a multi-mode swimming tactic and how it is affected by the surrounding environment using microscopy imaging. The detailed description of the bacterial motility in fundamental bacterial processes can provide new insights into the ecology of microorganisms.
N2 - Bakterien gehören zu den am weitesten verbreiteten Mikroorganismen mit einer essentiellen Bedeutung in vielen biologischen und okologischen Prozessen. Bakterien können entweder als unabhängige Individuen oder in organisierten Gemeinschaften leben. Auf dem Level einer einzelnen Zelle sind Interaktionen zwischen Bakterien, ihren Nachbarn und des umgebenden physikalischen und chemischen Umwelt die Grundlage von mikrobiellen Prozessen. Mikroskopische Bildgebungs techniken bieten attraktive und vielversprechende Möglichkeiten den Einfluß dieses Interaktionen auf die Dynamik von Bakterien zu untersuchen. Das ziel dieser Dissertation ist es, vier fundamentale bakterielle Prozesse mittels Lebendzell-Mikroskopie besser zu verstehen – die Einzelzellbewegung, die Chemotaxis, die Wechselwirkungen der Bakterien mit der Umgebung und ihre Kommunikation mit Nachbarzellen. Durch die Untersuchung dieser Prozesse konnten wir das Wissen über die bisher ungeklärten Mechanismen der bakteriellen Interaktionen erweitern.
Als Erstes untersuchten wir die Fortbewegung des Bodenbakteriums Pseudomonas putida (P. putida), welches mit Hilfe eines Flagellenantriebs schwimmt und eine komplexe multi-mode Schwimmstrategie aufweist. Kürzlich wurde veröffentlich, dass P. putida mehrere unterschiedliche Schwimmmodi besitzt – die Flagellen können den Zellkörper nach vorne drücken (push) oder ziehen (pull) oder sich um ihn wickeln (wrap). Unter Verwendung einer neuen Methode, der kombinierten Phasenkontrast- und Fluoreszenzmikroskopie, konnten die Schwimmmodi (push, pull oder wrap) für jede Schwimmphase automatisch aufgenommen werden, was eine vollständige Schwimmstatistik des multi-mode Schwimmers lieferte. Weiterhin zeigte die Untersuchung von Interaktionen mit einer festen Grenzschicht eine Asymmetrie bezüglich der verschiedenen Schwimmmodi. Im Gegensatz zu push und pull, der wrapped Modus nicht durch die feste Grenzschicht beeinflusst. Diese Ergebnisse lassen vermuten, dass eine multi-mode Schwimmstrategie dem Bakterium weitere möglichkeiten bietet, sich an die Umgebungsbedingungen anzupassen.
Als Nächstes haben wir bestimmt, wie P. putida in Richtung eines Lockstoffes navigiert (Chemotaxis). Wir haben herausgefunden, dass einzelne Schwimmmodi eine unterschiedliche chemotaktische Antwort in Nährstoff-gradienten zeigen. P. putida besitzt eine Asymmetrie in seiner chemotaktischen Ansprechbarkeit: der wrapped Modus (langsamer Schwimmmodus) wird vom Lockstoff beeinflusst, der push Modus (schneller Schwimmmodus) hingegen nicht. Diese Ergebnisse können als Ausgangspunkt gesehen werden, um komplexere Chemotaxisstrategien von mulit-mode Schwimmern zu verstehen, die über das bekannte Musterbeispiel Escherichia coli hinaus gehen, des nur einen schwimmmodus aufweist.
schließend haben wir die Zelldynamik in dichten Kulturen untersucht. Neben den physikalischen Interaktionen mit den Nachbarzellen, kommunizieren zellen ihre Aktivitäten und organisieren ihr Populationsverhalten über quorum sensing. Moleküle, die von den Bakterienzellen in die Umgebung sekretiert werden, wirken als Signale und regulieren das Verhalten der Zellpopulation. Wir haben die Bewegung von P. putida in hoher Zelldichte untersucht, indem wir die Zellen unterschiedlichen Konzentrationen dieses Moleküle aussetzten. Wir haben festgestellt, dass größere Mengen dieser signalstoffe in der Umgebung die Einzelzelldynamik beeinflusst haben. Dies lässt uns vermuten, dass sich die Zell-Zell-Kommunikation auch auf die Flagellendynamik auswirkt.
Zusammenfassend zeigt diese Dissertation mittels Mikroskopie die Dynamik von einem Bakterium mit multi-mode Schwimmstrategie und wie die umgebende Umwelt diese Dynamik beeinflußt. Die detaillierte Beschreibung der Bakterienmotilität in grundlegenden bakteriellen Prozessen kann neue Erkenntnisse für die ökologie der Mikroorganismen bringen.
T2 - Bewegungsstrategien von bakteriellenmulti-mode Schwimmern
KW - Single-cell motility
KW - Einzelzellbewegung
KW - Chemotaxis
KW - Chemotaxis
KW - Flagellen
KW - Flagella
KW - Bacteria
KW - Bakterien
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-475806
ER -
TY - JOUR
A1 - Voigt, Christian
A1 - Scholl, Julia M.
A1 - Bauer, Juliane
A1 - Teige, Tobias
A1 - Yovel, Yossi
A1 - Kramer-Schadt, Stephanie
A1 - Gras, Pierre
T1 - Movement responses of common noctule bats to the illuminated urban landscape
JF - Landscape ecology
N2 - Context Cities are a challenging habitat for obligate nocturnal mammals because of the ubiquitous use of artificial light at night (ALAN). How nocturnal animals move in an urban landscape, particularly in response to ALAN is largely unknown. Objectives We studied the movement responses, foraging and commuting, of common noctules (Nyctalus noctula) to urban landscape features in general and ALAN in particular. Methods We equipped 20 bats with miniaturized GPS loggers in the Berlin metropolitan area and related spatial positions of bats to anthropogenic and natural landscape features and levels of ALAN. Results Common noctules foraged close to ALAN only next to bodies of water or well vegetated areas, probably to exploit swarms of insects lured by street lights. In contrast, they avoided illuminated roads, irrespective of vegetation cover nearby. Predictive maps identified most of the metropolitan area as non-favoured by this species because of high levels of impervious surfaces and ALAN. Dark corridors were used by common noctules for commuting and thus likely improved the permeability of the city landscape. Conclusions We conclude that the spatial use of common noctules, previously considered to be more tolerant to light than other bats, is largely constrained by ALAN. Our study is the first individual-based GPS tracking study to show sensitive responses of nocturnal wildlife to light pollution. Approaches to protect urban biodiversity need to include ALAN to safeguard the larger network of dark habitats for bats and other nocturnal species in cities.
KW - Urbanization
KW - GPS tracking
KW - Artificial light at night
KW - ALAN
KW - Habitat use
KW - Preference
KW - Movement
KW - Common noctule bat
Y1 - 2019
U6 - https://doi.org/10.1007/s10980-019-00942-4
SN - 0921-2973
SN - 1572-9761
VL - 35
IS - 1
SP - 189
EP - 201
PB - Springer
CY - Dordrecht
ER -
TY - JOUR
A1 - Amen, Rahma
A1 - Nagel, Rebecca
A1 - Hedt, Maximilian
A1 - Kirschbaum, Frank
A1 - Tiedemann, Ralph
T1 - Morphological differentiation in African weakly electric fish (genus Campylomormyrus) relates to substrate preferences
JF - Evolutionary Ecology
N2 - Under an ecological speciation scenario, the radiation of African weakly electric fish (genus Campylomormyrus) is caused by an adaptation to different food sources, associated with diversification of the electric organ discharge (EOD). This study experimentally investigates a phenotype-environment correlation to further support this scenario. Our behavioural experiments showed that three sympatric Campylomormyrus species with significantly divergent snout morphology differentially react to variation in substrate structure. While the short snout species (C. tamandua) exhibits preference to sandy substrate, the long snout species (C. rhynchophorus) significantly prefers a stone substrate for feeding. A third species with intermediate snout size (C. compressirostris) does not exhibit any substrate preference. This preference is matched with the observation that long-snouted specimens probe deeper into the stone substrate, presumably enabling them to reach prey more distant to the substrate surface. These findings suggest that the diverse feeding apparatus in the genus Campylomormyrus may have evolved in adaptation to specific microhabitats, i.e., substrate structures where these fish forage. Whether the parallel divergence in EOD is functionally related to this adaptation or solely serves as a prezygotic isolation mechanism remains to be elucidated.
KW - ecological speciation
KW - feeding behaviour
KW - electric fish
KW - trophic apparatus
KW - evolutionary ecology
Y1 - 2020
U6 - https://doi.org/10.1007/s10682-020-10043-3
SN - 0269-7653
SN - 1573-8477
VL - 34
IS - 3
SP - 427
EP - 437
PB - Springer Science
CY - Dordrecht
ER -
TY - GEN
A1 - Amen, Rahma
A1 - Nagel, Rebecca
A1 - Hedt, Maximilian
A1 - Kirschbaum, Frank
A1 - Tiedemann, Ralph
T1 - Morphological differentiation in African weakly electric fish (genus Campylomormyrus) relates to substrate preferences
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Under an ecological speciation scenario, the radiation of African weakly electric fish (genus Campylomormyrus) is caused by an adaptation to different food sources, associated with diversification of the electric organ discharge (EOD). This study experimentally investigates a phenotype-environment correlation to further support this scenario. Our behavioural experiments showed that three sympatric Campylomormyrus species with significantly divergent snout morphology differentially react to variation in substrate structure. While the short snout species (C. tamandua) exhibits preference to sandy substrate, the long snout species (C. rhynchophorus) significantly prefers a stone substrate for feeding. A third species with intermediate snout size (C. compressirostris) does not exhibit any substrate preference. This preference is matched with the observation that long-snouted specimens probe deeper into the stone substrate, presumably enabling them to reach prey more distant to the substrate surface. These findings suggest that the diverse feeding apparatus in the genus Campylomormyrus may have evolved in adaptation to specific microhabitats, i.e., substrate structures where these fish forage. Whether the parallel divergence in EOD is functionally related to this adaptation or solely serves as a prezygotic isolation mechanism remains to be elucidated.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1416
KW - ecological speciation
KW - feeding behaviour
KW - electric fish
KW - trophic apparatus
KW - evolutionary ecology
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-518714
SN - 1866-8372
IS - 3
ER -