TY - GEN
A1 - Prát, Tomáš
A1 - Hajny ́, Jakub
A1 - Grunewald, Wim
A1 - Vasileva, Mina
A1 - Molnár, Gergely
A1 - Tejos, Ricardo
A1 - Schmid, Markus
A1 - Sauer, Michael
A1 - Friml, Jiří
T1 - WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1123
KW - apical-basal axis
KW - arabidopsis-thaliana
KW - root gravitropism
KW - DNA-binding
KW - gene-expression
KW - transport
KW - efflux
KW - canalization
KW - plants
KW - phosphorylation
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446331
SN - 1866-8372
IS - 1123
ER -
TY - GEN
A1 - Paraskevopoulou, Sofia
A1 - Dennis, Alice B.
A1 - Weithoff, Guntram
A1 - Hartmann, Stefanie
A1 - Tiedemann, Ralph
T1 - Within species expressed genetic variability and gene expression response to different temperatures in the rotifer Brachionus calyciflorus sensu stricto
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Genetic divergence is impacted by many factors, including phylogenetic history, gene flow, genetic drift, and divergent selection. Rotifers are an important component of aquatic ecosystems, and genetic variation is essential to their ongoing adaptive diversification and local adaptation. In addition to coding sequence divergence, variation in gene expression may relate to variable heat tolerance, and can impose ecological barriers within species. Temperature plays a significant role in aquatic ecosystems by affecting species abundance, spatio-temporal distribution, and habitat colonization. Recently described (formerly cryptic) species of the Brachionus calyciflorus complex exhibit different temperature tolerance both in natural and in laboratory studies, and show that B. calyciflorus sensu stricto (s.s.) is a thermotolerant species. Even within B. calyciflorus s.s., there is a tendency for further temperature specializations. Comparison of expressed genes allows us to assess the impact of stressors on both expression and sequence divergence among disparate populations within a single species. Here, we have used RNA-seq to explore expressed genetic diversity in B. calyciflorus s.s. in two mitochondrial DNA lineages with different phylogenetic histories and differences in thermotolerance. We identify a suite of candidate genes that may underlie local adaptation, with a particular focus on the response to sustained high or low temperatures. We do not find adaptive divergence in established candidate genes for thermal adaptation. Rather, we detect divergent selection among our two lineages in genes related to metabolism (lipid metabolism, metabolism of xenobiotics).
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 796
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441050
SN - 1866-8372
IS - 796
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 - 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 - GEN
A1 - Hoffmann, Julia
A1 - Hölker, Franz
A1 - Eccard, Jana
T1 - Welcome to the Dark Side
BT - Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1231
KW - light pollution
KW - inter-individual differences
KW - animal personality
KW - Myodes glareolus
KW - ALAN
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544702
SN - 1866-8372
ER -
TY - GEN
A1 - Köchy, Martin
A1 - Wilson, Scott D.
T1 - Variation in nitrogen deposition and available soil nitrogen in a forest–grassland ecotone in Canada
N2 - Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local-scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha⁻¹ yr⁻¹). N deposition was on average higher ton clayrich luvisols than on brunisols, and areas burned 1 – 15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On grazed sites, differences between fire treatments were small, presumably because the removal of biomass by grazers reduced the effect of fire. Aspen invades native grassland in this region, and our results suggest that fire without grazing might reinforce the expansion of forest into grassland facilitated by N deposition.
KW - fire
KW - grazing
KW - vegetation type
KW - soil type
KW - shrubland
KW - forest invasion
KW - subboreal
KW - aspen parkland
KW - Canada
Y1 - 2004
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5768
ER -
TY - GEN
A1 - Kiemel, Katrin
A1 - Gurke, Marie
A1 - Paraskevopoulou, Sofia
A1 - Havenstein, Katja
A1 - Weithoff, Guntram
A1 - Tiedemann, Ralph
T1 - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1305
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-578635
SN - 1866-8372
IS - 1305
ER -
TY - GEN
A1 - Drago, Claudia
A1 - Weithoff, Guntram
T1 - Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles
BT - The Role of Food Quantity and Quality
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5–25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1248
KW - microplastics
KW - population growth rate
KW - polystyrene
KW - polyamide
KW - silica beads
KW - fitness response
KW - rotifers
KW - Brachionus fernandoi
KW - Brachionus calyciflorus
KW - egg ratio
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-552615
SN - 1866-8372
IS - 1248
ER -
TY - GEN
A1 - Voss, Martin
A1 - Blenau, Wolfgang
A1 - Walz, Bernd
A1 - Baumann, Otto
T1 - V-ATPase deactivation in blowfly salivary glands is mediated by protein phosphatase 2C
N2 - The activity of vacuolar H+-ATPase (V-ATPase) in the apical membrane of blowfly (Calliphora vicina) salivary glands is regulated by the neurohormone serotonin (5-HT). 5-HT induces, via protein kinase A, the phosphorylation of V-ATPase subunit C and the assembly of V-ATPase holoenzymes. The protein phosphatase responsible for the dephosphorylation of subunit C and V-ATPase inactivation is not as yet known. We show here that inhibitors of protein phosphatases PP1 and PP2A (tautomycin, ocadaic acid) and PP2B (cyclosporin A, FK-506) do not prevent V-ATPase deactivation and dephosphorylation of subunit C. A decrease in the intracellular Mg2+ level caused by loading secretory cells with EDTA-AM leads to the activation of proton pumping in the absence of 5-HT, prolongs the 5-HT-induced response in proton pumping, and inhibits the dephosphorylation of subunit C. Thus, the deactivation of V-ATPase is most probably mediated by a protein phosphatase that is insensitive to okadaic acid and that requires Mg2+, namely, a member of the PP2C protein family. By molecular biological techniques, we demonstrate the expression of at least two PP2C protein family members in blowfly salivary glands. © 2009 Wiley Periodicals, Inc.
KW - vacuolar H+-ATPase
KW - assembly
KW - regulation
KW - protein phosphatise
KW - dephosphorylation
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44360
ER -
TY - GEN
A1 - Jones, Eppie R.
A1 - González-Fortes, Gloria M.
A1 - Connell, Sarah
A1 - Siska, Veronika
A1 - Eriksson, Anders
A1 - Martiniano, Rui
A1 - McLaughlin, Russell L.
A1 - Llorente, Marcos Gallego
A1 - Cassidy, Lara M.
A1 - Gamba, Cristina
A1 - Meshveliani, Tengiz
A1 - Bar-Yosef, Ofer
A1 - Müller, Werner
A1 - Belfer-Cohen, Anna
A1 - Matskevich, Zinovi
A1 - Jakeli, Nino
A1 - Higham, Thomas F. G.
A1 - Currat, Mathias
A1 - Lordkipanidze, David
A1 - Hofreiter, Michael
A1 - Manica, Andrea
A1 - Pinhasi, Ron
A1 - Bradley, Daniel G.
T1 - Upper Palaeolithic genomes reveal deep roots of modern Eurasians
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - We extend the scope of European palaeogenomics by sequencing the genomes of Late Upper Palaeolithic (13,300 years old, 1.4-fold coverage) and Mesolithic (9,700 years old, 15.4-fold) males from western Georgia in the Caucasus and a Late Upper Palaeolithic (13,700 years old, 9.5-fold) male from Switzerland. While we detect Late Palaeolithic–Mesolithic genomic continuity in both regions, we find that Caucasus hunter-gatherers (CHG) belong to a distinct ancient clade that split from western hunter-gatherers ∼45 kya, shortly after the expansion of anatomically modern humans into Europe and from the ancestors of Neolithic farmers ∼25 kya, around the Last Glacial Maximum. CHG genomes significantly contributed to the Yamnaya steppe herders who migrated into Europe ∼3,000 BC, supporting a formative Caucasus influence on this important Early Bronze age culture. CHG left their imprint on modern populations from the Caucasus and also central and south Asia possibly marking the arrival of Indo-Aryan languages.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1334
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439317
SN - 1866-8372
IS - 1334
ER -
TY - GEN
A1 - Bergholz, Kolja
A1 - Kober, Klarissa
A1 - Jeltsch, Florian
A1 - Schmidt, Kristina
A1 - Weiß, Lina
T1 - Trait means or variance
BT - What determines plant species' local and regional occurrence in fragmented dry grasslands?
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - One of the few laws in ecology is that communities consist of few common and many rare taxa. Functional traits may help to identify the underlying mechanisms of this community pattern, since they correlate with different niche dimensions. However, comprehensive studies are missing that investigate the effects of species mean traits (niche position) and intraspecific trait variability (ITV, niche width) on species abundance. In this study, we investigated fragmented dry grasslands to reveal trait-occurrence relationships in plants at local and regional scales. We predicted that (a) at the local scale, species occurrence is highest for species with intermediate traits, (b) at the regional scale, habitat specialists have a lower species occurrence than generalists, and thus, traits associated with stress-tolerance have a negative effect on species occurrence, and (c) ITV increases species occurrence irrespective of the scale. We measured three plant functional traits (SLA = specific leaf area, LDMC = leaf dry matter content, plant height) at 21 local dry grassland communities (10 m × 10 m) and analyzed the effect of these traits and their variation on species occurrence. At the local scale, mean LDMC had a positive effect on species occurrence, indicating that stress-tolerant species are the most abundant rather than species with intermediate traits (hypothesis 1). We found limited support for lower specialist occurrence at the regional scale (hypothesis 2). Further, ITV of LDMC and plant height had a positive effect on local occurrence supporting hypothesis 3. In contrast, at the regional scale, plants with a higher ITV of plant height were less frequent. We found no evidence that the consideration of phylogenetic relationships in our analyses influenced our findings. In conclusion, both species mean traits (in particular LDMC) and ITV were differently related to species occurrence with respect to spatial scale. Therefore, our study underlines the strong scale-dependency of trait-abundance relationships.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1151
KW - LMA
KW - niche width
KW - plant functional trait
KW - scale-dependency
KW - species abundance
KW - trait-environment relationship
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-519905
SN - 1866-8372
SP - 3357
EP - 3365
ER -
TY - GEN
A1 - Klauschies, Toni
A1 - Vasseur, David A.
A1 - Gaedke, Ursula
T1 - Trait adaptation promotes species coexistence in diverse predator and prey communities
N2 - Species can adjust their traits in response to selection which may strongly influence species coexistence. Nevertheless, current theory mainly assumes distinct and time-invariant trait values. We examined the combined effects of the range and the speed of trait adaptation on species coexistence using an innovative multispecies predator–prey model. It allows for temporal trait changes of all predator and prey species and thus simultaneous coadaptation within and among trophic levels. We show that very small or slow trait adaptation did not facilitate coexistence because the stabilizing niche differences were not sufficient to offset the fitness differences. In contrast, sufficiently large and fast trait adaptation jointly promoted stable or neutrally stable species coexistence. Continuous trait adjustments in response to selection enabled a temporally variable convergence and divergence of species traits; that is, species became temporally more similar (neutral theory) or dissimilar (niche theory) depending on the selection pressure, resulting over time in a balance between niche differences stabilizing coexistence and fitness differences promoting competitive exclusion. Furthermore, coadaptation allowed prey and predator species to cluster into different functional groups. This equalized the fitness of similar species while maintaining sufficient niche differences among functionally different species delaying or preventing competitive exclusion. In contrast to previous studies, the emergent feedback between biomass and trait dynamics enabled supersaturated coexistence for a broad range of potential trait adaptation and parameters. We conclude that accounting for trait adaptation may explain stable and supersaturated species coexistence for a broad range of environmental conditions in natural systems when the absence of such adaptive changes would preclude it. Small trait changes, coincident with those that may occur within many natural populations, greatly enlarged the number of coexisting species.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 227
KW - Coadaptation
KW - equalizing and stabilizing mechanisms
KW - maintenance of functional diversity
KW - niche and fitness differences
KW - supersaturated species coexistence
KW - trait convergence and divergence
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-91498
SN - 1866-8372
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 - GEN
A1 - Üstün, Suayib
A1 - Bartetzko, Verena
A1 - Börnke, Frederik
T1 - The Xanthomonas effector XopJ triggers a conditional hypersensitive response upon treatment of N. benthamiana leaves with salicylic acid
T2 - Frontiers in plant science
N2 - XopJ is a Xanthomonas type III effector protein that promotes bacterial virulence on susceptible pepper plants through the inhibition of the host cell proteasome and a resultant suppression of salicylic acid (SA) - dependent defense responses. We show here that Nicotiana benthamiana leaves transiently expressing XopJ display hypersensitive response (HR) -like symptoms when exogenously treated with SA. This apparent avirulence function of XopJ was further dependent on effector myristoylation as well as on an intact catalytic triad, suggesting a requirement of its enzymatic activity for HR-like symptom elicitation. The ability of XopJ to cause a HR-like symptom development upon SA treatment was lost upon silencing of SGT1 and NDR1, respectively, but was independent of EDS1 silencing, suggesting that XopJ is recognized by an R protein of the CC-NBS-LRR class. Furthermore, silencing of NPR1 abolished the elicitation of HR-like symptoms in XopJ expressing leaves after SA application. Measurement of the proteasome activity indicated that proteasome inhibition by XopJ was alleviated in the presence of SA, an effect that was not observed in NPR1 silenced plants. Our results suggest that XopJ - triggered HR-like symptoms are closely related to the virulence function of the effector and that XopJ follows a two-signal model in order to elicit a response in the non-host plant N. benthamiana.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 432
KW - Xanthomonas
KW - type-III effector
KW - XopJ
KW - avirulence
KW - salicylic acid
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-406537
ER -
TY - GEN
A1 - Otto, Nils
A1 - Marelja, Zvonimir
A1 - Schoofs, Andreas
A1 - Kranenburg, Holger
A1 - Bittern, Jonas
A1 - Yildirim, Kerem
A1 - Berh, Dimitri
A1 - Bethke, Maria
A1 - Thomas, Silke
A1 - Rode, Sandra
A1 - Risse, Benjamin
A1 - Jiang, Xiaoyi
A1 - Pankratz, Michael
A1 - Leimkühler, Silke
A1 - Klämbt, Christian
T1 - The sulfite oxidase Shopper controls neuronal activity by regulating glutamate homeostasis in Drosophila ensheathing glia
T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2 - Specialized glial subtypes provide support to developing and functioning neural networks. Astrocytes modulate information processing by neurotransmitter recycling and release of neuromodulatory substances, whereas ensheathing glial cells have not been associated with neuromodulatory functions yet. To decipher a possible role of ensheathing glia in neuronal information processing, we screened for glial genes required in the Drosophila central nervous system for normal locomotor behavior. Shopper encodes a mitochondrial sulfite oxidase that is specifically required in ensheathing glia to regulate head bending and peristalsis. shopper mutants show elevated sulfite levels affecting the glutamate homeostasis which then act on neuronal network function. Interestingly, human patients lacking the Shopper homolog SUOX develop neurological symptoms, including seizures. Given an enhanced expression of SUOX by oligodendrocytes, our findings might indicate that in both invertebrates and vertebrates more than one glial cell type may be involved in modulating neuronal activity.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 975
KW - molybdenum cofactor deficiency
KW - blood-brain-barrier
KW - larval locomotion
KW - energy-metabolism
KW - cerebral-cortex
KW - astrocytes
KW - behavior
KW - cells
KW - transmission
KW - disease
KW - Diseases of the nervous system
KW - Glial biology
KW - Glial development
KW - Neurotransmitters
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426205
SN - 1866-8372
IS - 975
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 - GEN
A1 - Tiedemann, Kim
A1 - Iobbi-Nivol, Chantal
A1 - Leimkühler, Silke
T1 - The Role of the Nucleotides in the Insertion of the bis-Molybdopterin Guanine Dinucleotide Cofactor into apo-Molybdoenzymes
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The role of the GMP nucleotides of the bis-molybdopterin guanine dinucleotide (bis-MGD) cofactor of the DMSO reductase family has long been a subject of discussion. The recent characterization of the bis-molybdopterin (bis-Mo-MPT) cofactor present in the E. coli YdhV protein, which differs from bis-MGD solely by the absence of the nucleotides, now enables studying the role of the nucleotides of bis-MGD and bis-MPT cofactors in Moco insertion and the activity of molybdoenzymes in direct comparison. Using the well-known E. coli TMAO reductase TorA as a model enzyme for cofactor insertion, we were able to show that the GMP nucleotides of bis-MGD are crucial for the insertion of the bis-MGD cofactor into apo-TorA.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1268
KW - bis-MGD
KW - chaperone
KW - molybdenum cofactor
KW - TMAO reductase
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-561728
SN - 1866-8372
SP - 1
EP - 15
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - GEN
A1 - Jannasch, Franziska
A1 - Nickel, Daniela
A1 - Schulze, Matthias Bernd
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 - GEN
A1 - Fer, Istem
A1 - Tietjen, Britta
A1 - Jeltsch, Florian
A1 - Wolff, Christian Michael
T1 - The influence of El Nino-Southern Oscillation regimes on eastern African vegetation and its future implications under the RCP8.5 warming scenario
N2 - The El Nino-Southern Oscillation (ENSO) is the main driver of the interannual variability in eastern African rainfall, with a significant impact on vegetation and agriculture and dire consequences for food and social security. In this study, we identify and quantify the ENSO contribution to the eastern African rainfall variability to forecast future eastern African vegetation response to rainfall variability related to a predicted intensified ENSO. To differentiate the vegetation variability due to ENSO, we removed the ENSO signal from the climate data using empirical orthogonal teleconnection (EOT) analysis. Then, we simulated the ecosystem carbon and water fluxes under the historical climate without components related to ENSO teleconnections. We found ENSO-driven patterns in vegetation response and confirmed that EOT analysis can successfully produce coupled tropical Pacific sea surface temperature-eastern African rainfall teleconnection from observed datasets. We further simulated eastern African vegetation response under future climate change as it is projected by climate models and under future climate change combined with a predicted increased ENSO intensity. Our EOT analysis highlights that climate simulations are still not good at capturing rainfall variability due to ENSO, and as we show here the future vegetation would be different from what is simulated under these climate model outputs lacking accurate ENSO contribution. We simulated considerable differences in eastern African vegetation growth under the influence of an intensified ENSO regime which will bring further environmental stress to a region with a reduced capacity to adapt effects of global climate change and food security.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 394
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403853
ER -
TY - GEN
A1 - Ogunkola, Moses Olalekan
A1 - Guiraudie-Capraz, Gaelle
A1 - Féron, François
A1 - Leimkühler, Silke
T1 - The Human Mercaptopyruvate Sulfurtransferase TUM1 Is Involved in Moco Biosynthesis, Cytosolic tRNA Thiolation and Cellular Bioenergetics in Human Embryonic Kidney Cells
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Sulfur is an important element that is incorporated into many biomolecules in humans. The incorporation and transfer of sulfur into biomolecules is, however, facilitated by a series of different sulfurtransferases. Among these sulfurtransferases is the human mercaptopyruvate sulfurtransferase (MPST) also designated as tRNA thiouridine modification protein (TUM1). The role of the human TUM1 protein has been suggested in a wide range of physiological processes in the cell among which are but not limited to involvement in Molybdenum cofactor (Moco) biosynthesis, cytosolic tRNA thiolation and generation of H2S as signaling molecule both in mitochondria and the cytosol. Previous interaction studies showed that TUM1 interacts with the L-cysteine desulfurase NFS1 and the Molybdenum cofactor biosynthesis protein 3 (MOCS3). Here, we show the roles of TUM1 in human cells using CRISPR/Cas9 genetically modified Human Embryonic Kidney cells. Here, we show that TUM1 is involved in the sulfur transfer for Molybdenum cofactor synthesis and tRNA thiomodification by spectrophotometric measurement of the activity of sulfite oxidase and liquid chromatography quantification of the level of sulfur-modified tRNA. Further, we show that TUM1 has a role in hydrogen sulfide production and cellular bioenergetics.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1307
KW - Moco biosynthesis
KW - sulfite oxidase
KW - cytosolic tRNA thiolation
KW - 5-methoxycarbonylmethyl-2-thiouridine
KW - H2S biosynthesis
KW - cellular bioenergetics
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-579580
SN - 1866-8372
IS - 1307
ER -
TY - GEN
A1 - Schedina, Ina Maria
A1 - Groth, Detlef
A1 - Schlupp, Ingo
A1 - Tiedemann, Ralph
T1 - The gonadal transcriptome of the unisexual Amazon molly Poecilia formosa in comparison to its sexual ancestors, Poecilia mexicana and Poecilia latipinna
N2 - Abstract
Background
The unisexual Amazon molly (Poecilia formosa) originated from a hybridization between two sexual species, the sailfin molly (Poecilia latipinna) and the Atlantic molly (Poecilia mexicana). The Amazon molly reproduces clonally via sperm-dependent parthenogenesis (gynogenesis), in which the sperm of closely related species triggers embryogenesis of the apomictic oocytes, but typically does not contribute genetic material to the next generation. We compare for the first time the gonadal transcriptome of the Amazon molly to those of both ancestral species, P. mexicana and P. latipinna.
Results
We sequenced the gonadal transcriptomes of the P. formosa and its parental species P. mexicana and P. latipinna using Illumina RNA-sequencing techniques (paired-end, 100 bp). De novo assembly of about 50 million raw read pairs for each species was performed using Trinity, yielding 106,922 transcripts for P. formosa, 115,175 for P. latipinna, and 133,025 for P. mexicana after eliminating contaminations. On the basis of sequence similarity comparisons to other teleost species and the UniProt databases, functional annotation, and differential expression analysis, we demonstrate the similarity of the transcriptomes among the three species. More than 40% of the transcripts for each species were functionally annotated and about 70% were assigned to orthologous genes of a closely related species. Differential expression analysis between the sexual and unisexual species uncovered 2035 up-regulated and 564 down-regulated genes in P. formosa. This was exemplary validated for six genes by qRT-PCR.
Conclusions
We identified more than 130 genes related to meiosis and reproduction within the apomictically reproducing P. formosa. Overall expression of these genes seems to be down-regulated in the P. formosa transcriptome compared to both ancestral species (i.e., 106 genes down-regulated, 29 up-regulated). A further 35 meiosis and reproduction related genes were not found in the P. formosa transcriptome, but were only expressed in the sexual species. Our data support the hypothesis of general down-regulation of meiosis-related genes in the apomictic Amazon molly. Furthermore, the obtained dataset and identified gene catalog will serve as a resource for future research on the molecular mechanisms behind the reproductive mode of this unisexual species.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 412
KW - Differential gene expression
KW - Gynogenesis
KW - Hybrid speciation
KW - Meiosis
KW - Poecilia formosa
KW - Poecilia latipinna
KW - Poecilia mexicana
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409299
ER -
TY - GEN
A1 - Kruse, Julia
A1 - Kummer, Volker
A1 - Shivas, Roger G.
A1 - Thines, Marco
T1 - The first smut fungus, Thecaphora anthemidis sp. nov. (Glomosporiaceae), described from Anthemis (Asteraceae)
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - There are 63 known species of Thecaphora (Glomosporiaceae, Ustilaginomycotina), a third of which occur on Asteraceae. These smut fungi produce yellowish-brown to reddish-brown masses of spore balls in specific, mostly regenerative, plant organs. A species of Thecaphora was collected in the flower heads of Anthemis chia (Anthemideae, Asteraceae) on Rhodes Island, Greece, in 2015 and 2017, which represents the first smut record of a smut fungus on a host plant species in this tribe. Based on its distinctive morphology, host species and genetic divergence, this species is described as Thecaphora anthemidis sp. nov. Molecular barcodes of the ITS region are provided for this and several other species of Thecaphora. A phylogenetic and morphological comparison to closely related species showed that Th. anthemidis differed from other species of Thecaphora. Thecaphora anthemidis produced loose spore balls in the flower heads and peduncles of Anthemis chia unlike other flower-infecting species.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 995
KW - Glomosporiaceae
KW - host specificity
KW - internal transcribed spacer
KW - molecular phylogenetics
KW - smut fungi
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446377
SN - 1866-8372
SP - 39
EP - 50
ER -
TY - GEN
A1 - Yarman, Aysu
A1 - Scheller, Frieder W.
T1 - The first electrochemical MIP sensor for tamoxifen
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - We present an electrochemical MIP sensor for tamoxifen (TAM)-a nonsteroidal anti-estrogen-which is based on the electropolymerisation of an O-phenylenediamine. resorcinol mixture directly on the electrode surface in the presence of the template molecule. Up to now only. bulk. MIPs for TAM have been described in literature, which are applied for separation in chromatography columns. Electro-polymerisation of the monomers in the presence of TAM generated a film which completely suppressed the reduction of ferricyanide. Removal of the template gave a markedly increased ferricyanide signal, which was again suppressed after rebinding as expected for filling of the cavities by target binding. The decrease of the ferricyanide peak of the MIP electrode depended linearly on the TAM concentration between 1 and 100 nM. The TAM-imprinted electrode showed a 2.3 times higher recognition of the template molecule itself as compared to its metabolite 4-hydroxytamoxifen and no cross-reactivity with the anticancer drug doxorubucin was found. Measurements at + 1.1 V caused a fouling of the electrode surface, whilst pretreatment of TAM with peroxide in presence of HRP generated an oxidation product which was reducible at 0 mV, thus circumventing the polymer formation and electrochemical interferences.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1046
KW - molecularly imprinted polymers
KW - anticancer drug
KW - tamoxifen
KW - electropolymerisation
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-476173
SN - 1866-8372
IS - 1046
ER -
TY - GEN
A1 - Schröder, Florian
A1 - Lisso, Janina
A1 - Lange, Peggy
A1 - Müssig, Carsten
T1 - The extracellular EXO protein mediates cell expansion in Arabidopsis leaves
N2 - Background: The EXO (EXORDIUM) gene was identified as a potential mediator of brassinosteroid (BR)-promoted growth. It is part of a gene family with eight members in Arabidopsis. EXO gene expression is under control of BR, and EXO overexpression promotes shoot and root growth. In this study, the consequences of loss of EXO function are described. Results: The exo loss of function mutant showed diminished leaf and root growth and reduced biomass production. Light and scanning electron microscopy analyses revealed that impaired leaf growth is due to reduced cell expansion. Epidermis, palisade, and spongy parenchyma cells were smaller in comparison to the wild-type. The exo mutant showed reduced brassinolide-induced cotyledon and hypocotyl growth. In contrast, exo roots were significantly more sensitive to the inhibitory effect of synthetic brassinolide. Apart from reduced growth, exo did not show severe morphological abnormalities. Gene expression analyses of leaf material identified genes that showed robust EXO-dependent expression. Growth-related genes such as WAK1, EXP5, and KCS1, and genes involved in primary and secondary metabolism showed weaker expression in exo than in wild-type plants. However, the vast majority of BR-regulated genes were normally expressed in exo. HA- and GFP-tagged EXO proteins were targeted to the apoplast. Conclusion: The EXO gene is essential for cell expansion in leaves. Gene expression patterns and growth assays suggest that EXO mediates BR-induced leaf growth. However, EXO does not control BR-levels or BR-sensitivity in the shoot. EXO presumably is involved in a signalling process which coordinates BR-responses with environmental or developmental signals. The hypersensitivity of exo roots to BR suggests that EXO plays a diverse role in the control of BR responses in the root.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 139
KW - Plant transformation
KW - Gene expression
KW - Wall proteins
KW - Thaliana
KW - Brassinosteroids
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45107
ER -
TY - GEN
A1 - Kettner, Marie Therese
A1 - Oberbeckmann, Sonja
A1 - Labrenz, Matthias
A1 - Grossart, Hans-Peter
T1 - The Eukaryotic Life on Microplastics in Brackish Ecosystems
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 741
KW - microeukaryotes
KW - plastic-associated biofilms
KW - Baltic Sea
KW - polyethylene
KW - polystyrene
KW - diversity profiles
KW - network analysis
KW - next-generation sequencing
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434996
SN - 1866-8372
IS - 741
ER -
TY - GEN
A1 - Ceulemans, Ruben
A1 - Gaedke, Ursula
A1 - Klauschies, Toni
A1 - Guill, Christian
T1 - The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 744
KW - early-warning signals
KW - top-down control
KW - community ecology
KW - regime shifts
KW - food webs
KW - compensatory dynamics
KW - consumer diversity
KW - metabolic theory
KW - rapid evolution
KW - stable states
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435439
SN - 1866-8372
IS - 744
ER -
TY - GEN
A1 - De Cahsan, Binia
A1 - Westbury, Michael V.
A1 - Drews, Hauke
A1 - Tiedemann, Ralph
T1 - The complete mitochondrial genome of a European fire-bellied toad (Bombina bombina) from Germany
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - The European fire-bellied toad, Bombina bombina, is a small aquatic toad belonging to the family Bombinatoridae. The species is native to the lowlands of Central and Eastern Europe, where population numbers have been in decline in recent past decades. Here, we present the first complete mitochondrial genome of the endangered European fire-bellied toad from Northern Germany recovered using iterative mapping. Phylogenetic analyses including other representatives of the Bombinatoridae placed our German specimen as sister to a Polish B. bombina sequence with high support. This finding is congruent with the postulated Pleistocene history of the species. Our complete mitochondrial genome represents an important resource for further population analysis of the European fire-bellied toad, especially those found within Germany.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 532
KW - Bombina bombina
KW - Fire-bellied toad
KW - mitogenome
KW - conservation genetics
KW - population delimitation
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423222
SN - 1866-8372
IS - 532
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 - GEN
A1 - Riedel, Simona
A1 - Siemiatkowska, Beata
A1 - Watanabe, Mutsumi
A1 - Müller, Christina S.
A1 - Schünemann, Volker
A1 - Hoefgen, Rainer
A1 - Leimkühler, Silke
T1 - The ABCB7-Like Transporter PexA in Rhodobacter capsulatus Is Involved in the Translocation of Reactive Sulfur Species
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - The mitochondrial ATP-binding cassette (ABC) transporters ABCB7 in humans, Atm1 in yeast and ATM3 in plants, are highly conserved in their overall architecture and particularly in their glutathione binding pocket located within the transmembrane spanning domains. These transporters have attracted interest in the last two decades based on their proposed role in connecting the mitochondrial iron sulfur (Fe–S) cluster assembly with its cytosolic Fe–S cluster assembly (CIA) counterpart. So far, the specific compound that is transported across the membrane remains unknown. In this report we characterized the ABCB7-like transporter Rcc02305 in Rhodobacter capsulatus, which shares 47% amino acid sequence identity with its mitochondrial counterpart. The constructed interposon mutant strain in R. capsulatus displayed increased levels of intracellular reactive oxygen species without a simultaneous accumulation of the cellular iron levels. The inhibition of endogenous glutathione biosynthesis resulted in an increase of total glutathione levels in the mutant strain. Bioinformatic analysis of the amino acid sequence motifs revealed a potential aminotransferase class-V pyridoxal-50-phosphate (PLP) binding site that overlaps with the Walker A motif within the nucleotide binding domains of the transporter. PLP is a well characterized cofactor of L-cysteine desulfurases like IscS and NFS1 which has a role in the formation of a protein-bound persulfide group within these proteins. We therefore suggest renaming the ABCB7-like transporter Rcc02305 in R. capsulatus to PexA for PLP binding exporter. We further suggest that this ABC-transporter in R. capsulatus is involved in the formation and export of polysulfide species to the periplasm.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 740
KW - ABCB7
KW - persulfide
KW - polysulfide
KW - glutathione
KW - ABC transporter
KW - Walker A motif
KW - pyridoxal-50-phosphate
Y1 - 1019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434975
SN - 1866-8372
IS - 740
ER -
TY - GEN
A1 - Taron, Ulrike H.
A1 - Lell, Moritz
A1 - Barlow, Axel
A1 - Paijmans, Johanna L. A.
T1 - Testing of Alignment Parameters for Ancient Samples
BT - Evaluating and Optimizing Mapping Parameters for Ancient Samples Using the TAPAS Tool
T2 - Genes
N2 - High-throughput sequence data retrieved from ancient or other degraded samples has led to unprecedented insights into the evolutionary history of many species, but the analysis of such sequences also poses specific computational challenges. The most commonly used approach involves mapping sequence reads to a reference genome. However, this process becomes increasingly challenging with an elevated genetic distance between target and reference or with the presence of contaminant sequences with high sequence similarity to the target species. The evaluation and testing of mapping efficiency and stringency are thus paramount for the reliable identification and analysis of ancient sequences. In this paper, we present ‘TAPAS’, (Testing of Alignment Parameters for Ancient Samples), a computational tool that enables the systematic testing of mapping tools for ancient data by simulating sequence data reflecting the properties of an ancient dataset and performing test runs using the mapping software and parameter settings of interest. We showcase TAPAS by using it to assess and improve mapping strategy for a degraded sample from a banded linsang (Prionodon linsang), for which no closely related reference is currently available. This enables a 1.8-fold increase of the number of mapped reads without sacrificing mapping specificity. The increase of mapped reads effectively reduces the need for additional sequencing, thus making more economical use of time, resources, and sample material.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 415
KW - ancient DNA
KW - short-read mapping
KW - palaeogenomics
KW - alignment sensitivity / specificity
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409683
ER -
TY - GEN
A1 - Epp, Laura Saskia
A1 - Kruse, Stefan
A1 - Kath, Nadja J.
A1 - Stoof-Leichsenring, Kathleen Rosemarie
A1 - Tiedemann, Ralph
A1 - Pestryakova, Luidmila Agafyevna
A1 - Herzschuh, Ulrike
T1 - Temporal and spatial patterns of mitochondrial haplotype and species distributions in Siberian larches inferred from ancient environmental DNA and modeling
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Changes in species' distributions are classically projected based on their climate envelopes. For Siberian forests, which have a tremendous significance for vegetation-climate feedbacks, this implies future shifts of each of the forest-forming larch (Larix) species to the north-east. However, in addition to abiotic factors, reliable projections must assess the role of historical biogeography and biotic interactions. Here, we use sedimentary ancient DNA and individual-based modelling to investigate the distribution of larch species and mitochondrial haplotypes through space and time across the treeline ecotone on the southern Taymyr peninsula, which at the same time presents a boundary area of two larch species. We find spatial and temporal patterns, which suggest that forest density is the most influential driver determining the precise distribution of species and mitochondrial haplotypes. This suggests a strong influence of competition on the species' range shifts. These findings imply possible climate change outcomes that are directly opposed to projections based purely on climate envelopes. Investigations of such fine-scale processes of biodiversity change through time are possible using paleoenvironmental DNA, which is available much more readily than visible fossils and can provide information at a level of resolution that is not reached in classical palaeoecology.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1052
KW - ecological genetics
KW - ecological modelling
KW - palaeoecology
KW - plant ecology
KW - climate change
KW - introgression
KW - temperature
KW - treeline
KW - vegetation
KW - mitochondrial haplotypes
KW - Siberian larch
KW - larch species
KW - range shifts
KW - vegetation-climate feedbacks
KW - ecosystems
KW - impacts
KW - dynamics
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468352
SN - 1866-8372
IS - 1052
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 - GEN
A1 - Mantzouki, Evanthia
A1 - Lürling, Miquel
A1 - Fastner, Jutta
A1 - Domis, Lisette Nicole de Senerpont
A1 - Wilk-Woźniak, Elżbieta
A1 - Koreiviene, Judita
A1 - Seelen, Laura
A1 - Teurlincx, Sven
A1 - Verstijnen, Yvon
A1 - Krztoń, Wojciech
A1 - Walusiak, Edward
A1 - Karosienė, Jūratė
A1 - Kasperovičienė, Jūratė
A1 - Savadova, Ksenija
A1 - Vitonytė, Irma
A1 - Cillero-Castro, Carmen
A1 - Budzyńska, Agnieszka
A1 - Goldyn, Ryszard
A1 - Kozak, Anna
A1 - Rosińska, Joanna
A1 - Szeląg-Wasielewska, Elżbieta
A1 - Domek, Piotr
A1 - Jakubowska-Krepska, Natalia
A1 - Kwasizur, Kinga
A1 - Messyasz, Beata
A1 - Pełechata, Aleksandra
A1 - Pełechaty, Mariusz
A1 - Kokocinski, Mikolaj
A1 - García-Murcia, Ana
A1 - Real, Monserrat
A1 - Romans, Elvira
A1 - Noguero-Ribes, Jordi
A1 - Duque, David Parreño
A1 - Fernández-Morán, Elísabeth
A1 - Karakaya, Nusret
A1 - Häggqvist, Kerstin
A1 - Beklioğlu, Meryem
A1 - Filiz, Nur
A1 - Levi, Eti E.
A1 - Iskin, Uğur
A1 - Bezirci, Gizem
A1 - Tavşanoğlu, Ülkü Nihan
A1 - Özhan, Koray
A1 - Gkelis, Spyros
A1 - Panou, Manthos
A1 - Fakioglu, Özden
A1 - Avagianos, Christos
A1 - Kaloudis, Triantafyllos
A1 - Çelik, Kemal
A1 - Yilmaz, Mete
A1 - Marcé, Rafael
A1 - Catalán, Nuria
A1 - Bravo, Andrea G.
A1 - Buck, Moritz
A1 - Colom-Montero, William
A1 - Mustonen, Kristiina
A1 - Pierson, Don
A1 - Yang, Yang
A1 - Raposeiro, Pedro M.
A1 - Gonçalves, Vítor
A1 - Antoniou, Maria G.
A1 - Tsiarta, Nikoletta
A1 - McCarthy, Valerie
A1 - Perello, Victor C.
A1 - Feldmann, Tõnu
A1 - Laas, Alo
A1 - Panksep, Kristel
A1 - Tuvikene, Lea
A1 - Gagala, Ilona
A1 - Mankiewicz-Boczek, Joana
A1 - Yağcı, Meral Apaydın
A1 - Çınar, Şakir
A1 - Çapkın, Kadir
A1 - Yağcı, Abdulkadir
A1 - Cesur, Mehmet
A1 - Bilgin, Fuat
A1 - Bulut, Cafer
A1 - Uysal, Rahmi
A1 - Obertegger, Ulrike
A1 - Boscaini, Adriano
A1 - Flaim, Giovanna
A1 - Salmaso, Nico
A1 - Cerasino, Leonardo
A1 - Richardson, Jessica
A1 - Visser, Petra M.
A1 - Verspagen, Jolanda M. H.
A1 - Karan, Tünay
A1 - Soylu, Elif Neyran
A1 - Maraşlıoğlu, Faruk
A1 - Napiórkowska-Krzebietke, Agnieszka
A1 - Ochocka, Agnieszka
A1 - Pasztaleniec, Agnieszka
A1 - Antão-Geraldes, Ana M.
A1 - Vasconcelos, Vitor
A1 - Morais, João
A1 - Vale, Micaela
A1 - Köker, Latife
A1 - Akçaalan, Reyhan
A1 - Albay, Meriç
A1 - Maronić, Dubravka Špoljarić
A1 - Stević, Filip
A1 - Pfeiffer, Tanja Žuna
A1 - Fonvielle, Jeremy Andre
A1 - Straile, Dietmar
A1 - Rothhaupt, Karl-Otto
A1 - Hansson, Lars-Anders
A1 - Urrutia-Cordero, Pablo
A1 - Bláha, Luděk
A1 - Geriš, Rodan
A1 - Fránková, Markéta
A1 - Koçer, Mehmet Ali Turan
A1 - Alp, Mehmet Tahir
A1 - Remec-Rekar, Spela
A1 - Elersek, Tina
A1 - Triantis, Theodoros
A1 - Zervou, Sevasti-Kiriaki
A1 - Hiskia, Anastasia
A1 - Haande, Sigrid
A1 - Skjelbred, Birger
A1 - Madrecka, Beata
A1 - Nemova, Hana
A1 - Drastichova, Iveta
A1 - Chomova, Lucia
A1 - Edwards, Christine
A1 - Sevindik, Tuğba Ongun
A1 - Tunca, Hatice
A1 - Önem, Burçin
A1 - Aleksovski, Boris
A1 - Krstić, Svetislav
A1 - Vucelić, Itana Bokan
A1 - Nawrocka, Lidia
A1 - Salmi, Pauliina
A1 - Machado-Vieira, Danielle
A1 - Oliveira, Alinne Gurjão De
A1 - Delgado-Martín, Jordi
A1 - García, David
A1 - Cereijo, Jose Luís
A1 - Gomà, Joan
A1 - Trapote, Mari Carmen
A1 - Vegas-Vilarrúbia, Teresa
A1 - Obrador, Biel
A1 - Grabowska, Magdalena
A1 - Karpowicz, Maciej
A1 - Chmura, Damian
A1 - Úbeda, Bárbara
A1 - Gálvez, José Ángel
A1 - Özen, Arda
A1 - Christoffersen, Kirsten Seestern
A1 - Warming, Trine Perlt
A1 - Kobos, Justyna
A1 - Mazur-Marzec, Hanna
A1 - Pérez-Martínez, Carmen
A1 - Ramos-Rodríguez, Eloísa
A1 - Arvola, Lauri
A1 - Alcaraz-Párraga, Pablo
A1 - Toporowska, Magdalena
A1 - Pawlik-Skowronska, Barbara
A1 - Niedźwiecki, Michał
A1 - Pęczuła, Wojciech
A1 - Leira, Manel
A1 - Hernández, Armand
A1 - Moreno-Ostos, Enrique
A1 - Blanco, José María
A1 - Rodríguez, Valeriano
A1 - Montes-Pérez, Jorge Juan
A1 - Palomino, Roberto L.
A1 - Rodríguez-Pérez, Estela
A1 - Carballeira, Rafael
A1 - Camacho, Antonio
A1 - Picazo, Antonio
A1 - Rochera, Carlos
A1 - Santamans, Anna C.
A1 - Ferriol, Carmen
A1 - Romo, Susana
A1 - Soria, Juan Miguel
A1 - Dunalska, Julita
A1 - Sieńska, Justyna
A1 - Szymański, Daniel
A1 - Kruk, Marek
A1 - Kostrzewska-Szlakowska, Iwona
A1 - Jasser, Iwona
A1 - Žutinić, Petar
A1 - Udovič, Marija Gligora
A1 - Plenković-Moraj, Anđelka
A1 - Frąk, Magdalena
A1 - Bańkowska-Sobczak, Agnieszka
A1 - Wasilewicz, Michał
A1 - Özkan, Korhan
A1 - Maliaka, Valentini
A1 - Kangro, Kersti
A1 - Grossart, Hans-Peter
A1 - Paerl, Hans W.
A1 - Carey, Cayelan C.
A1 - Ibelings, Bas W.
T1 - Temperature effects explain continental scale distribution of cyanobacterial toxins
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1105
KW - microcystin
KW - anatoxin
KW - cylindrospermopsin
KW - temperature
KW - direct effects
KW - indirect effects
KW - spatial distribution
KW - European Multi Lake Survey
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427902
SN - 1866-8372
IS - 1105
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 - GEN
A1 - Machens, Fabian
A1 - Balazadeh, Salma
A1 - Müller-Röber, Bernd
A1 - Messerschmidt, Katrin
T1 - Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae
N2 - Orthogonal systems for heterologous protein expression as well as for the engineering of synthetic gene regulatory circuits in hosts like Saccharomyces cerevisiae depend on synthetic transcription factors (synTFs) and corresponding cis-regulatory binding sites. We have constructed and characterized a set of synTFs based on either transcription activator-like effectors or CRISPR/Cas9, and corresponding small synthetic promoters (synPs) with minimal sequence identity to the host’s endogenous promoters. The resulting collection of functional synTF/synP pairs confers very low background expression under uninduced conditions, while expression output upon induction of the various synTFs covers a wide range and reaches induction factors of up to 400. The broad spectrum of expression strengths that is achieved will be useful for various experimental setups, e.g., the transcriptional balancing of expression levels within heterologous pathways or the construction of artificial regulatory networks. Furthermore, our analyses reveal simple rules that enable the tuning of synTF expression output, thereby allowing easy modification of a given synTF/synP pair. This will make it easier for researchers to construct tailored transcriptional control systems.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 393
KW - JUB1
KW - chimeric transcription factors
KW - dead Cas9
KW - gene expression
KW - synthetic biology
KW - synthetic circuits
KW - transcriptional regulation
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403804
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 - GEN
A1 - Biterova, Ekaterina
A1 - Esmaeeli Moghaddam Tabalvandani, Mariam
A1 - Alanen, Heli I.
A1 - Saaranen, Mirva
A1 - Ruddock, Lloyd W.
T1 - Structures of Angptl3 and Angptl4
BT - modulators of triglyceride levels and coronary artery disease
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Coronary artery disease is the most common cause of death globally and is linked to a number of risk factors including serum low density lipoprotein, high density lipoprotein, triglycerides and lipoprotein(a). Recently two proteins, angiopoietin-like protein 3 and 4, have emerged from genetic studies as being factors that significantly modulate plasma triglyceride levels and coronary artery disease. The exact function and mechanism of action of both proteins remains to be elucidated, however, mutations in these proteins results in up to 34% reduction in coronary artery disease and inhibition of function results in reduced plasma triglyceride levels. Here we report the crystal structures of the fibrinogen-like domains of both proteins. These structures offer new insights into the reported loss of function mutations, the mechanisms of action of the proteins and open up the possibility for the rational design of low molecular weight inhibitors for intervention in coronary artery disease.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1048
KW - angiopoitin-like 4
KW - of-function mutations
KW - cardiovascular-disease
KW - lipoprotein-lipase
KW - heart-disease
KW - risk
KW - recognition
KW - protein
KW - metaanalysis
KW - association
KW - cardiovascular biology
KW - x-ray crystallography
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-467943
SN - 1866-8372
IS - 1048
ER -
TY - GEN
A1 - Hoppert, Michael
A1 - Reimer, Rudolph
A1 - Kemmling, Anne
A1 - Schröder, Annekatrin
A1 - Günzl, Bettina
A1 - Heinken, Thilo
T1 - Structure and reactivity of a biological soil crust from a xeric sandy soil in Central Europe
N2 - The investigation was designed to explore the structure, composition and activity of a biological soil crust on an acidic, sandy soil from a temperate climate. The crust covers several hundreds of square meters on the hilltop of a large terminal moraine. The conjugate alga Zygogonium ericetorum forms the essential matrix for the crust, a dense web of algal filaments with interspersed lichens and mosses. The crust is composed of three layers, with an uppermost layer consisting nearly entirely of a dense algal mat. In lower layers, a parasitic fungus, penetrating the algal cells, is another important component of the crust community. In this soil crust, photosynthetic and respiratory activity is stabilized at low water activities.
KW - biological soil crust
KW - desiccation tolerance
KW - electron microscopy
KW - Fusarium oxysporum
KW - Zygogonium ericetorum
Y1 - 2004
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5872
ER -
TY - GEN
A1 - Schieferdecker, Anne
A1 - Wendler, Petra
T1 - Structural mapping of missense mutations in the Pex1/Pex6 complex
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Peroxisome biogenesis disorders (PBDs) are nontreatable hereditary diseases with a broad range of severity. Approximately 65% of patients are affected by mutations in the peroxins Pex1 and Pex6. The proteins form the heteromeric Pex1/Pex6 complex, which is important for protein import into peroxisomes. To date, no structural data are available for this AAA+ ATPase complex. However, a wealth of information can be transferred from low-resolution structures of the yeast scPex1/scPex6 complex and homologous, well-characterized AAA+ ATPases. We review the abundant records of missense mutations described in PBD patients with the aim to classify and rationalize them by mapping them onto a homology model of the human Pex1/Pex6 complex. Several mutations concern functionally conserved residues that are implied in ATP hydrolysis and substrate processing. Contrary to fold destabilizing mutations, patients suffering from function-impairing mutations may not benefit from stabilizing agents, which have been reported as potential therapeutics for PBD patients.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1072
KW - Zellweger syndrome spectrum disorder (ZSSD)
KW - Zellweger
KW - structure
KW - Pex1
KW - Pex6
KW - mutation
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472843
SN - 1866-8372
IS - 1072
ER -
TY - GEN
A1 - Wacker, Alexander
A1 - von Elert, Eric
T1 - Strong influences of larval diet history on subsequent post-settlement growth in the freshwater mollusc Dreissena polymorpha
N2 - Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 064
KW - Dreissena polymorpha
KW - food quality
KW - fatty acid
KW - life history
KW - metamorphosis
KW - PUFA
Y1 - 2002
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17627
ER -
TY - GEN
A1 - Bornhorst, Dorothee
A1 - Abdelilah-Seyfried, Salim
T1 - Strong as a Hippo’s Heart: Biomechanical Hippo Signaling During Zebrafish Cardiac Development
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The heart is comprised of multiple tissues that contribute to its physiological functions. During development, the growth of myocardium and endocardium is coupled and morphogenetic processes within these separate tissue layers are integrated. Here, we discuss the roles of mechanosensitive Hippo signaling in growth and morphogenesis of the zebrafish heart. Hippo signaling is involved in defining numbers of cardiac progenitor cells derived from the secondary heart field, in restricting the growth of the epicardium, and in guiding trabeculation and outflow tract formation. Recent work also shows that myocardial chamber dimensions serve as a blueprint for Hippo signaling-dependent growth of the endocardium. Evidently, Hippo pathway components act at the crossroads of various signaling pathways involved in embryonic zebrafish heart development. Elucidating how biomechanical Hippo signaling guides heart morphogenesis has direct implications for our understanding of cardiac physiology and pathophysiology.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1236
KW - Hippo signaling
KW - Yap1/Wwtr1 (Taz)
KW - cardiac development
KW - mechanobiology
KW - endocardium
KW - myocardium
KW - zebrafish
KW - intra-organ-communication
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-548731
SN - 1866-8372
SP - 1
EP - 10
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - GEN
A1 - Müller, Marik
A1 - Nedielkov, Ruslan
A1 - Arndt, Katja M.
T1 - Strategies for Enzymatic Inactivation of the Veterinary Antibiotic Florfenicol
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Large quantities of the antibiotic florfenicol are used in animal farming and aquaculture, contaminating the ecosystem with antibiotic residues and promoting antimicrobial resistance, ultimately leading to untreatable multidrug-resistant pathogens. Florfenicol-resistant bacteria often activate export mechanisms that result in resistance to various structurally unrelated antibiotics. We devised novel strategies for the enzymatic inactivation of florfenicol in different media, such as saltwater or milk. Using a combinatorial approach and selection, we optimized a hydrolase (EstDL136) for florfenicol cleavage. Reaction kinetics were followed by time-resolved NMR spectroscopy. Importantly, the hydrolase remained active in different media, such as saltwater or cow milk. Various environmentally-friendly application strategies for florfenicol inactivation were developed using the optimized hydrolase. As a potential filter device for cost-effective treatment of waste milk or aquacultural wastewater, the hydrolase was immobilized on Ni-NTA agarose or silica as carrier materials. In two further application examples, the hydrolase was used as cell extract or encapsulated with a semi-permeable membrane. This facilitated, for example, florfenicol inactivation in whole milk, which can help to treat waste milk from medicated cows, to be fed to calves without the risk of inducing antibiotic resistance. Enzymatic inactivation of antibiotics, in general, enables therapeutic intervention without promoting antibiotic resistance.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1266
KW - aquaculture
KW - antibiotic inactivation
KW - enzyme optimization
KW - enzymatic inactivation
KW - florfenicol
KW - immobilization
KW - industrial farming
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-561621
SN - 1866-8372
SP - 1
EP - 18
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - GEN
A1 - Köchy, Martin
T1 - Stochastic time series of daily precipitation for the interior of Israel
N2 - This contribution describes a generator of stochastic time series of daily precipitation for the interior of Israel from c. 90 to 900 mm mean annual precipitation (MAP) as a tool for studies of daily rain variability. The probability of rainfall on a given day of the year is described by a regular Gaussian peak curve function. The amount of rain is drawn randomly from an exponential distribution whose mean is the daily mean rain amount (averaged across years for each day of the year) described by a flattened Gaussian peak curve. Parameters for the curves have been calculated from monthly aggregated, long-term rain records from seven meteorological stations. Parameters for arbitrary points on the MAP gradient are calculated from a regression equation with MAP as the only independent variable. The simple structure of the generator allows it to produce time series with daily rain patterns that are projected under climate change scenarios and simultaneously control MAP. Increasing within-year variability of daily precipitation amounts also increases among-year variability of MAP as predicted by global circulation models. Thus, the time series incorporate important characteristics for climate change research and represent a flexible tool for simulations of daily vegetation or surface hydrology dynamics.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 029
KW - stochastische Zeitreihen
KW - täglicher Niederschlag
KW - Israel
KW - Klimawandel
KW - stochastic time series
KW - daily precipitation
KW - Israel
KW - climate change
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13155
ER -
TY - GEN
A1 - Liu, Qingting
A1 - Li, Xiaoping
A1 - Fettke, Jörg
T1 - Starch granules in Arabidopsis thaliana mesophyll and guard cells show similar morphology but differences in size and number
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Transitory starch granules result from complex carbon turnover and display specific situations during starch synthesis and degradation. The fundamental mechanisms that specify starch granule characteristics, such as granule size, morphology, and the number per chloroplast, are largely unknown. However, transitory starch is found in the various cells of the leaves of Arabidopsis thaliana, but comparative analyses are lacking. Here, we adopted a fast method of laser confocal scanning microscopy to analyze the starch granules in a series of Arabidopsis mutants with altered starch metabolism. This allowed us to separately analyze the starch particles in the mesophyll and in guard cells. In all mutants, the guard cells were always found to contain more but smaller plastidial starch granules than mesophyll cells. The morphological properties of the starch granules, however, were indiscernible or identical in both types of leaf cells.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1143
KW - starch granules
KW - starch metabolism
KW - starch granule initiation
KW - starch granule number per chloroplast
KW - starch morphology
KW - mesophyll cell
KW - guard cell
KW - LCSM
KW - Arabidopsis thaliana
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-511067
SN - 1866-8372
IS - 1143
ER -
TY - GEN
A1 - Liu, Qingting
A1 - Zhou, Yuan
A1 - Fettke, Jörg
T1 - Starch granule size and morphology of Arabidopsis thaliana starch-related mutants analyzed during diurnal rhythm and development
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1245
KW - starch metabolism
KW - starch granule
KW - starch granule size
KW - starch granule morphology
KW - LCSM
KW - Arabidopsis thaliana
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-550291
SN - 1866-8372
VL - 26
SP - 1
EP - 9
PB - Universitätsverlag Potsdam
CY - Potsdam
ET - 19
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 - GEN
A1 - Szymanski, Jedrzej
A1 - Jozefczuk, Szymon
A1 - Nikoloski, Zoran
A1 - Selbig, Joachim
A1 - Nikiforova, Victoria
A1 - Catchpole, Gareth
A1 - Willmitzer, Lothar
T1 - Stability of metabolic correlations under changing environmental conditions in Escherichia coli : a systems approach
N2 - Background: Biological systems adapt to changing environments by reorganizing their cellula r and physiological program with metabolites representing one important response level. Different stresses lead to both conserved and specific responses on the metabolite level which should be reflected in the underl ying metabolic network. Methodology/Principal Findings: Starting from experimental data obtained by a GC-MS based high-throughput metabolic profiling technology we here develop an approach that: (1) extracts network representations from metabolic conditiondependent data by using pairwise correlations, (2) determines the sets of stable and condition-dependent correlations based on a combination of statistical significance and homogeneity tests, and (3) can identify metabolites related to the stress response, which goes beyond simple ob servation s about the changes of metabolic concentrations. The approach was tested with Escherichia colias a model organism observed under four different environmental stress conditions (cold stress, heat stress, oxidative stress, lactose diau xie) and control unperturbed conditions. By constructing the stable network component, which displays a scale free topology and small-world characteristics, we demonstrated that: (1) metabolite hubs in this reconstructed correlation networks are significantly enriched for those contained in biochemical networks such as EcoCyc, (2) particular components of the stable network are enriched for functionally related biochemical path ways, and (3) ind ependently of the response scale, based on their importance in the reorganization of the cor relation network a set of metabolites can be identified which represent hypothetical candidates for adjusting to a stress-specific response. Conclusions/Significance: Network-based tools allowed the identification of stress-dependent and general metabolic correlation networks. This correlation-network-ba sed approach does not rely on major changes in concentration to identify metabolites important for st ress adaptation, but rather on the changes in network properties with respect to metabolites. This should represent a useful complementary technique in addition to more classical approaches.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 147
KW - Small-world networks
KW - saccharomyces-cerevisiae
KW - trehalose synthesis
KW - gene-expression
KW - stress-response
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45253
ER -
TY - GEN
A1 - Batsios, Petros
A1 - Ren, Xiang
A1 - Baumann, Otto
A1 - Larochelle, Denis A.
A1 - Gräf, Ralph
T1 - Src1 is a Protein of the Inner Nuclear Membrane Interacting with the Dictyostelium Lamin NE81
N2 - The nuclear envelope (NE) consists of the outer and inner nuclear membrane (INM), whereby the latter is bound to the nuclear lamina. Src1 is a Dictyostelium homologue of the helix-extension-helix family of proteins, which also includes the human lamin-binding protein MAN1. Both endogenous Src1 and GFP-Src1 are localized to the NE during the entire cell cycle. Immuno-electron microscopy and light microscopy after differential detergent treatment indicated that Src1 resides in the INM. FRAP experiments with GFP-Src1 cells suggested that at least a fraction of the protein could be stably engaged in forming the nuclear lamina together with the Dictyostelium lamin NE81. Both a BioID proximity assay and mis-localization of soluble, truncated mRFP-Src1 at cytosolic clusters consisting of an intentionally mis-localized mutant of GFP-NE81 confirmed an interaction of Src1 and NE81. Expression GFP-Src11–646, a fragment C-terminally truncated after the first transmembrane domain, disrupted interaction of nuclear membranes with the nuclear lamina, as cells formed protrusions of the NE that were dependent on cytoskeletal pulling forces. Protrusions were dependent on intact microtubules but not actin filaments. Our results indicate that Src1 is required for integrity of the NE and highlight Dictyostelium as a promising model for the evolution of nuclear architecture.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 263
KW - Dictyostelium
KW - HeH-protein
KW - LEM-domain protein
KW - lamin
KW - nuclear lamina
KW - nucleolus
KW - nucleus
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-97033
ER -
TY - GEN
A1 - Winkler, Eckart
A1 - Heinken, Thilo
T1 - Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L.
N2 - The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas was based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within one square meter. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of populationpattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sums of squares. These sums-ofsquares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25*25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sums of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1…2 m was indispensable for explaining the observed population spread that led to distances of at most 8 m from population origin within 3 years. Projections of population development over 4 additional years gave a diffusion-like increase of population area without any “outposts”. This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 152
KW - Pattern-oriented parameter estimation
KW - spatially explicit modelling
KW - individual-based model
KW - Melampyrum pratense
KW - seed dispersal
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46491
ER -
TY - GEN
A1 - Zwickel, Theresa
A1 - Kahl, Sandra
A1 - Klaffke, Horst
A1 - Rychlik, Michael
A1 - Müller, Marina E. H.
T1 - Spotlight on the underdogs
BT - an analysis of underrepresented alternaria mycotoxins formed depending on varying substrate, time and temperature conditions
N2 - Alternaria (A.) is a genus of widespread fungi capable of producing numerous, possibly health-endangering Alternaria toxins (ATs), which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 °C, 25 °C), substrate (rice, wheat kernels) and incubation time (4, 7, and 14 days) on the production of thirteen ATs and three sulfoconjugated ATs by three different Alternaria isolates from the species groups A. tenuissima and A. infectoria was determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 °C and with increasing incubation time all toxins were formed in high amounts by the two A. tenuissima strains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to the A. tenuissima strains, the A. infectoria strain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 353
KW - Alternaria infectoria
KW - A. tenuissima
KW - mycotoxin profile
KW - wheat
KW - rice
KW - Alternaria toxin sulfates
KW - modified Alternaria toxins
KW - altertoxins
KW - altenuic acid
KW - HPLC-MS/MS
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400438
ER -
TY - GEN
A1 - Senczuk, Gabriele
A1 - Havenstein, Katja
A1 - Milana, Valentina
A1 - Ripa, Chiara
A1 - De Simone, Emanuela
A1 - Tiedemann, Ralph
A1 - Castiglia, Riccardo
T1 - Spotlight on islands
BT - on the origin and diversification of an ancient lineage of the Italian wall lizard Podarcis siculus in the western Pontine Islands
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Groups of proximate continental islands may conceal more tangled phylogeographic patterns than oceanic archipelagos as a consequence of repeated sea level changes, which allow populations to experience gene flow during periods of low sea level stands and isolation by vicariant mechanisms during periods of high sea level stands. Here, we describe for the first time an ancient and diverging lineage of the Italian wall lizard Podarcis siculus from the western Pontine Islands. We used nuclear and mitochondrial DNA sequences of 156 individuals with the aim of unraveling their phylogenetic position, while microsatellite loci were used to test several a priori insular biogeographic models of migration with empirical data. Our results suggest that the western Pontine populations colonized the islands early during their Pliocene volcanic formation, while populations from the eastern Pontine Islands seem to have been introduced recently. The inter-island genetic makeup indicates an important role of historical migration, probably due to glacial land bridges connecting islands followed by a recent vicariant mechanism of isolation. Moreover, the most supported migration model predicted higher gene flow among islands which are geographically arranged in parallel. Considering the threatened status of small insular endemic populations, we suggest this new evolutionarily independent unit be given priority in conservation efforts.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 991
KW - mitochondrial dna sequences
KW - genetic diversity
KW - haplotype reconstruction
KW - evolutionary history
KW - geological evolution
KW - population structure
KW - Tyrrhenian Sea
KW - endemic lizard
KW - genotype data
KW - biogeography
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446360
SN - 1866-8372
IS - 991
ER -
TY - GEN
A1 - Kuehnel, Susanne
A1 - Kupfer, Alexander
T1 - Sperm storage in caecilian amphibians
N2 - Background: Female sperm storage has evolved independently multiple times among vertebrates to control reproduction in response to the environment. In internally fertilising amphibians, female salamanders store sperm in cloacal spermathecae, whereas among anurans sperm storage in oviducts is known only in tailed frogs. Facilitated through extensive field sampling following historical observations we tested for sperm storing structures in the female urogenital tract of fossorial, tropical caecilian amphibians.
Findings: In the oviparous Ichthyophis cf. kohtaoensis, aggregated sperm were present in a distinct region of the posterior oviduct but not in the cloaca in six out of seven vitellogenic females prior to oviposition. Spermatozoa were found most abundantly between the mucosal folds. In relation to the reproductive status decreased amounts of sperm were present in gravid females compared to pre-ovulatory females. Sperm were absent in females past oviposition.
Conclusions: Our findings indicate short-term oviductal sperm storage in the oviparous Ichthyophis cf. kohtaoensis. We assume that in female caecilians exhibiting high levels of parental investment sperm storage has evolved in order to optimally coordinate reproductive events and to increase fitness.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 375
KW - reproduction
KW - sperm storage
KW - amphibians
KW - caecilians
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400987
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 - GEN
A1 - Zurell, Damaris
A1 - König, Christian
A1 - Malchow, Anne-Kathleen
A1 - Kapitza, Simon
A1 - Bocedi, Greta
A1 - Travis, Justin M. J.
A1 - Fandos, Guillermo
T1 - Spatially explicit models for decision-making in animal conservation and restoration
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Models are useful tools for understanding and predicting ecological patterns and processes. Under ongoing climate and biodiversity change, they can greatly facilitate decision-making in conservation and restoration and help designing adequate management strategies for an uncertain future. Here, we review the use of spatially explicit models for decision support and to identify key gaps in current modelling in conservation and restoration. Of 650 reviewed publications, 217 publications had a clear management application and were included in our quantitative analyses. Overall, modelling studies were biased towards static models (79%), towards the species and population level (80%) and towards conservation (rather than restoration) applications (71%). Correlative niche models were the most widely used model type. Dynamic models as well as the gene-to-individual level and the community-to-ecosystem level were underrepresented, and explicit cost optimisation approaches were only used in 10% of the studies. We present a new model typology for selecting models for animal conservation and restoration, characterising model types according to organisational levels, biological processes of interest and desired management applications. This typology will help to more closely link models to management goals. Additionally, future efforts need to overcome important challenges related to data integration, model integration and decision-making. We conclude with five key recommendations, suggesting that wider usage of spatially explicit models for decision support can be achieved by 1) developing a toolbox with multiple, easier-to-use methods, 2) improving calibration and validation of dynamic modelling approaches and 3) developing best-practise guidelines for applying these models. Further, more robust decision-making can be achieved by 4) combining multiple modelling approaches to assess uncertainty, and 5) placing models at the core of adaptive management. These efforts must be accompanied by long-term funding for modelling and monitoring, and improved communication between research and practise to ensure optimal conservation and restoration outcomes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1243
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-549915
SN - 1866-8372
VL - 2022
SP - 1
EP - 16
PB - Universitätsverlag Potsdam
CY - Potsdam
ET - 4
ER -
TY - GEN
A1 - Lah, Ljerka
A1 - Trense, Daronja
A1 - Benke, Harald
A1 - Berggren, Per
A1 - Gunnlaugsson, Þorvaldur
A1 - Lockyer, Christina
A1 - Öztürk, Ayaka
A1 - Öztürk, Bayram
A1 - Pawliczka, Iwona
A1 - Roos, Anna
A1 - Siebert, Ursula
A1 - Skóra, Krzysztof
A1 - Víkingsson, Gísli
A1 - Tiedemann, Ralph
T1 - Spatially Explicit Analysis of Genome-Wide SNPs Detects Subtle Population Structure in a Mobile Marine Mammal, the Harbor Porpoise
N2 - The population structure of the highly mobile marine mammal, the harbor porpoise (Phocoena phocoena), in the Atlantic shelf waters follows a pattern of significant isolation-by-distance. The population structure of harbor porpoises from the Baltic Sea, which is connected with the North Sea through a series of basins separated by shallow underwater ridges, however, is more complex. Here, we investigated the population differentiation of harbor porpoises in European Seas with a special focus on the Baltic Sea and adjacent waters, using a population genomics approach. We used 2872 single nucleotide polymorphisms (SNPs), derived from double digest restriction-site associated DNA sequencing (ddRAD-seq), as well as 13 microsatellite loci and mitochondrial haplotypes for the same set of individuals. Spatial principal components analysis (sPCA), and Bayesian clustering on a subset of SNPs suggest three main groupings at the level of all studied regions: the Black Sea, the North Atlantic, and the Baltic Sea. Furthermore, we observed a distinct separation of the North Sea harbor porpoises from the Baltic Sea populations, and identified splits between porpoise populations within the Baltic Sea. We observed a notable distinction between the Belt Sea and the Inner Baltic Sea sub-regions. Improved delineation of harbor porpoise population assignments for the Baltic based on genomic evidence is important for conservation management of this endangered cetacean in threatened habitats, particularly in the Baltic Sea proper. In addition, we show that SNPs outperform microsatellite markers and demonstrate the utility of RAD-tags from a relatively small, opportunistically sampled cetacean sample set for population diversity and divergence analysis.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 295
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-100813
SN - 1866-8372
ER -
TY - GEN
A1 - Cahsan, Binia De
A1 - Kiemel, Katrin
A1 - Westbury, Michael V.
A1 - Lauritsen, Maike
A1 - Autenrieth, Marijke
A1 - Gollmann, Günter
A1 - Schweiger, Silke
A1 - Stenberg, Marika
A1 - Nyström, Per
A1 - Drews, Hauke
A1 - Tiedemann, Ralph
T1 - Southern introgression increases adaptive immune gene variability in northern range margin populations of Fire-bellied toad
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Northern range margin populations of the European fire-bellied toad (Bombina bombina) have rapidly declined during recent decades. Extensive agricultural land use has fragmented the landscape, leading to habitat disruption and loss, as well as eutrophication of ponds. In Northern Germany (Schleswig-Holstein) and Southern Sweden (Skåne), this population decline resulted in decreased gene flow from surrounding populations, low genetic diversity, and a putative reduction in adaptive potential, leaving populations vulnerable to future environmental and climatic changes. Previous studies using mitochondrial control region and nuclear transcriptome-wide SNP data detected introgressive hybridization in multiple northern B. bombina populations after unreported release of toads from Austria. Here, we determine the impact of this introgression by comparing the body conditions (proxy for fitness) of introgressed and nonintrogressed populations and the genetic consequences in two candidate genes for putative local adaptation (the MHC II gene as part of the adaptive immune system and the stress response gene HSP70 kDa). We detected regional differences in body condition and observed significantly elevated levels of within individual MHC allele counts in introgressed Swedish populations, associated with a tendency toward higher body weight, relative to regional nonintrogressed populations. These differences were not observed among introgressed and nonintrogressed German populations. Genetic diversity in both MHC and HSP was generally lower in northern than Austrian populations. Our study sheds light on the potential benefits of translocations of more distantly related conspecifics as a means to increase adaptive genetic variability and fitness of genetically depauperate range margin populations without distortion of local adaptation.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1177
KW - Bombina bombina
KW - heat shock protein
KW - introgression
KW - major histocompatibility complex
KW - scaled mass index
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-523883
SN - 1866-8372
IS - 14
ER -
TY - GEN
A1 - Blenau, Wolfgang
A1 - Rotte, Cathleen
A1 - Witte, Jeannine
A1 - Baumann, Otto
A1 - Walz, Bernd
T1 - Source, topography and excitatory effects of GABAergic innervation in cockroach salivary glands
N2 - Cockroach salivary glands are innervated by dopaminergic and serotonergic neurons. Both transmitters elicit saliva secretion. We studied the distribution pattern of neurons containing gamma-aminobutyric acid ( GABA) and their physiological role. Immunofluorescence revealed a GABA-immunoreactive axon that originates within the subesophageal ganglion at the salivary neuron 2 (SN2) and this extends within the salivary duct nerve towards the salivary gland. GABA-positive fibers form a network on most acinar lobules and a dense plexus in the interior of a minor fraction of acinar lobules. Co-staining with anti-synapsin revealed that some putative GABAergic terminals seem to make pre-synaptic contacts with GABA-negative release sites. Many putative GABAergic release sites are at some distance from other synapses and at distance from the acinar tissue. Intracellular recordings from isolated salivary glands have revealed that GABA does not affect the basolateral membrane potential of the acinar cells directly. When applied during salivary duct nerve stimulation, GABA enhances the electrical response of the acinar cells and increases the rates of fluid and protein secretion. The effect on electrical cell responses is mimicked by the GABA(B) receptor agonists baclofen and SKF97541, and blocked by the GABAB receptor antagonists CGP52432 and CGP54626. These findings indicate that GABA has a modulatory role in the control of salivation, acting presynaptically on serotonergic and/or dopaminergic neurotransmission.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 111
KW - GABA
KW - salivary gland
KW - innervation
KW - cockroach
KW - Periplaneta americana
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44353
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 - GEN
A1 - Heinken, Thilo
A1 - Schmidt, Marcus
A1 - von Oheimb, Goddert
A1 - Kriebitzsch, Wolf-Ulrich
A1 - Ellenberg, Hermann
T1 - Soil seed banks near rubbing trees indicate dispersal of plant species into forests by wild boar
N2 - Current knowledge about processes that generate long-distance dispersal of plants is still limited despite its importance for persistence of populations and colonization of new potential habitats. Today wild large mammals are presumed to be important vectors for long-distance transport of diaspores within and between European temperate forest patches, and in particular wild boars recently came into focus. Here we use a specific habit of wild boar, i.e. wallowing in mud and subsequent rubbing against trees, to evaluate epizoic dispersal of vascular plant diaspores. We present soil seed bank data from 27 rubbing trees versus 27 control trees from seven forest areas in Germany. The mean number of viable seeds and the plant species number were higher in soil samples near rubbing trees compared with control trees. Ten of the 20 most frequent species were more frequent, and many species exclusively appeared in the soil samples near rubbing trees. The large number of plant species and seeds – approximated > 1000 per tree – in the soils near rubbing trees is difficult to explain unless the majority were dispersed by wild boar. Hooked and bristly diaspores, i.e. those adapted to epizoochory, were more frequent, above that many species with unspecialised diaspores occurred exclusively near rubbing trees. Different to plant species closely tied to forest species which occur both in forest and open vegetation, and non-forest species were more frequent near rubbing trees compared with controls. These findings are consistent with previous studies on diaspore loads in the coats and hooves of shot wild boars. However, our method allows to identify the transport of diaspores from the open landscape into forest stands where they might especially emerge after disturbance, and a clustered distribution of epizoochorically dispersed seeds. Moreover, accumulation of seeds of wetness indicators near rubbing trees demonstrates directed dispersal of plant species inhabiting wet places between remote wallows.
N2 - Das aktuelle Wissen über Prozesse, die zur Fernausbreitung von Pflanzen führen, ist trotz ihrer Bedeutung für das Überleben von Populationen und die Besiedlung neuer potenzieller Habitate noch immer sehr begrenzt. Wildlebende Großsäuger sind heutzutage vermutlich wichtige Vektoren für den Ferntransport von Diasporen innerhalb und zwischen den einzelnen Waldflächen in Mitteleuropa, und speziell das Wildschwein (Sus scrofa L.) spielt dabei offenbar eine herausragende Rolle. Wir nutzen hier ein spezifisches Verhalten des Wildschweins – Suhlen im Schlamm und nachfolgendes Scheuern an sogenannten Malbäumen – um die epizoochore Ausbreitung von Gefäßpflanzen-Diasporen einzuschätzen. Dargestellt werden die Ergebnisse von Samenbank-Untersuchungen von 27 Malbäumen im Vergleich zu 27 Kontrollbäumen aus sieben Waldgebieten in Deutschland. Sowohl die mittlere Zahl lebensfähiger Samen als auch die Artenzahl waren höher in Bodenproben neben Malbäumen. Zehn der 20 in der Samenbank verbreitetsten Pflanzenarten hatten hier ihren Schwerpunkt, und viele Arten kamen ausschließlich in den neben Malbäumen gewonnenen Proben vor. Die große Zahl von Pflanzenarten und Samen – zumindest > 1000 pro Baum – im Boden an Malbäumen lässt sich nur durch die Aktivität der Wildschweine erklären. Mit Haken oder Borsten ausgestattete, d.h. an Epizoochorie angepasste Diasporen waren häufiger, aber auch viele Arten mit unspezialisierten Diasporen kamen ausschließlich in der Samenbank bei Malbäumen vor. Anders als weitgehend an Wald gebundene Pflanzenarten waren solche, die sowohl im Wald und im Offenland vorkommen, sowie nicht im Wald vorkommende Arten häufiger neben Malbäumen als neben Kontrollbäumen. Diese Befunde stimmen mit denen früherer Untersuchungen von Diasporenladungen im Fell und in den Hufen geschossener Wildschweine überein. Unsere Methode erlaubt darüber hinaus aber die Identifizierung des Diasporentransports aus dem Offenland in die Waldbestände, wo sie insbesondere nach Störungen keimen dürften, sowie einer ungleichmäßigen Verteilung epizoochor ausgebreiteter Diasporen. Außerdem zeigt die Akkumulation von Samen von Nässezeigern neben den Malbäumen eine gezielte Ausbreitung nasse Standorte bewohnender Pflanzenarten zwischen entfernt gelegenen Suhlen.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 150
KW - Diaspore morphology
KW - directed dispersal
KW - epizoochory
KW - long-distance dispersal
KW - Sus scrofa
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46476
ER -
TY - GEN
A1 - Schumann, Silvia
A1 - Terao, Mineko
A1 - Garattini, Enrico
A1 - Saggu, Miguel
A1 - Lendzian, Friedhelm
A1 - Hildebrandt, Peter
A1 - Leimkühler, Silke
T1 - Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1
N2 - Mouse aldehyde oxidase (mAOX1) forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Eschericia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 134
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45030
ER -
TY - GEN
A1 - Agne, Stefanie
A1 - Preick, Michaela
A1 - Straube, Nicolas
A1 - Hofreiter, Michael
T1 - Simultaneous Barcode Sequencing of Diverse Museum Collection Specimens Using a Mixed RNA Bait Set
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - A growing number of publications presenting results from sequencing natural history collection specimens reflect the importance of DNA sequence information from such samples. Ancient DNA extraction and library preparation methods in combination with target gene capture are a way of unlocking archival DNA, including from formalin-fixed wet-collection material. Here we report on an experiment, in which we used an RNA bait set containing baits from a wide taxonomic range of species for DNA hybridisation capture of nuclear and mitochondrial targets for analysing natural history collection specimens. The bait set used consists of 2,492 mitochondrial and 530 nuclear RNA baits and comprises specific barcode loci of diverse animal groups including both invertebrates and vertebrates. The baits allowed to capture DNA sequence information of target barcode loci from 84% of the 37 samples tested, with nuclear markers being captured more frequently and consensus sequences of these being more complete compared to mitochondrial markers. Samples from dry material had a higher rate of success than wet-collection specimens, although target sequence information could be captured from 50% of formalin-fixed samples. Our study illustrates how efforts to obtain barcode sequence information from natural history collection specimens may be combined and are a way of implementing barcoding inventories of scientific collection material.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1293
KW - target capture
KW - type specimens
KW - molecular species identification
KW - museum specimens
KW - cross-species capture
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-574600
SN - 1866-8372
IS - 1293
ER -
TY - GEN
A1 - Wurzbacher, Christian
A1 - Fuchs, Andrea
A1 - Attermeyer, Katrin
A1 - Frindte, Katharina
A1 - Grossart, Hans-Peter
A1 - Hupfer, Michael
A1 - Casper, Peter
A1 - Monaghan, Michael T.
T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments.
Methods
We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to 137Cs dating and was sectioned into layers 1–4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota.
Results
Community β-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5–14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions.
Conclusions
By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper “replacement horizon” is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower “depauperate horizon” is characterized by low taxonomic richness, more stable “low-energy” conditions, and a dominance of enigmatic Archaea.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1111
KW - Archaea
KW - Eukaryota
KW - Bacteria
KW - community
KW - freshwater
KW - lake
KW - DNA metabarcoding
KW - beta-diversity
KW - sediment
KW - turnover
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431965
SN - 1866-8372
IS - 1111
ER -
TY - GEN
A1 - Leimkühler, Silke
A1 - Bühning, Martin
A1 - Beilschmidt, Lena
T1 - Shared sulfur mobilization routes for tRNA thiolation and molybdenum cofactor biosynthesis in prokaryotes and eukaryotes
T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2 - Modifications of transfer RNA (tRNA) have been shown to play critical roles in the biogenesis, metabolism, structural stability and function of RNA molecules, and the specific modifications of nucleobases with sulfur atoms in tRNA are present in pro- and eukaryotes. Here, especially the thiomodifications xm(5)s(2)U at the wobble position 34 in tRNAs for Lys, Gln and Glu, were suggested to have an important role during the translation process by ensuring accurate deciphering of the genetic code and by stabilization of the tRNA structure. The trafficking and delivery of sulfur nucleosides is a complex process carried out by sulfur relay systems involving numerous proteins, which not only deliver sulfur to the specific tRNAs but also to other sulfur-containing molecules including iron-sulfur clusters, thiamin, biotin, lipoic acid and molybdopterin (MPT). Among the biosynthesis of these sulfur-containing molecules, the biosynthesis of the molybdenum cofactor (Moco) and the synthesis of thio-modified tRNAs in particular show a surprising link by sharing protein components for sulfur mobilization in pro- and eukaryotes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1015
KW - tRNA
KW - molybdenum cofactor
KW - persulfide
KW - thiocarboxylate
KW - thionucleosides
KW - sulfurtransferase
KW - l-cysteine desulfurase
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-475011
SN - 1866-8372
IS - 1015
ER -
TY - GEN
A1 - Martin-Creuzburg, Dominik
A1 - Massier, Tamara
A1 - Wacker, Alexander
T1 - Sex-specific differences in essential lipid requirements of Daphnia magna
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Sex-specific differences in nutritional requirements may crucially influence the performances of the sexes, which may have implications for sexual reproduction and thus is of great ecological and evolutionary interest. In the freshwater model species Daphnia magna, essential lipid requirements have been extensively studied. Dietary deficiencies in sterols and polyunsaturated fatty acids (PUFA) have been shown to constrain somatic growth and parthenogenetic reproduction of female Daphnia. In contrast, nutrient requirements of male Daphnia have not been studied yet. Supplementation experiments were conducted to investigate differences in sterol (cholesterol) and PUFA (eicosapentaenoic acid, EPA) requirements between female and male D. magna. Thresholds for sterol-limited juvenile growth were higher in females than in males, suggesting that females are more susceptible to dietary sterol deficiencies than males. Sex-specific differences in maximum somatic growth rates were evident primarily in the presence of dietary EPA; females could not exploit their generally higher growth potential in the absence of dietary PUFA. However, the thresholds for EPA-limited growth did not differ between sexes, suggesting that both sexes have similar dietary EPA requirements during juvenile growth. During a life history experiment, the gain in body dry mass was higher in females than in males, irrespective of food treatment. In both sexes, the gain in body dry mass increased significantly upon EPA supplementation, indicating that both sexes benefited from dietary EPA supply also later in life. However, the positive effects of EPA supplementation were most pronounced for female reproduction-related traits (i.e., clutch sizes, egg dry masses, and total dry mass investment in reproduction). The high maternal investment in reproduction resulted in a depletion of nutrients in female somata. In contrast, the comparatively low paternal investment in reproduction allowed for the accumulation of nutrients in male somata. We conclude that males are generally less susceptible to dietary nutrient deficiencies than females, because they can rely more on internal body stores. Our data suggest that the performances of the sexes are differentially influenced by lipid-mediated food quality, which may have consequences for sexual reproduction and thus the production of resting eggs and the maintenance of Daphnia populations.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1050
KW - allocation
KW - cholesterol
KW - eicosapentaenoic acid
KW - food quality
KW - male Daphnia
KW - polyunsaturated fatty acids
KW - sterols
KW - lipid limitation thresholds
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-469099
SN - 1866-8372
IS - 1050
ER -
TY - GEN
A1 - Zhu, Fangjun
A1 - Schlupp, Ingo
A1 - Tiedemann, Ralph
T1 - Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors
N2 - The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs’ embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess–as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of erα in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 265
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-97119
ER -
TY - GEN
A1 - Köchy, Martin
A1 - Bråkenhielm, Sven
T1 - Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs
N2 - The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7–13 kg ha−1 year−1) and lower bulk N deposition (4–6 kg ha−1 year−1) in southern Sweden during 1982–1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cover and richness varied among growth forms, vegetation types, and deposition regions. Cover in spruce forests decreased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs cover decreased faster with low deposition. Cover of bryophytes in spruce forests increased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs and deciduous forests there was a strong non-linear increase with moderate deposition. The trend of number of vascular plants was constant with moderate and decreased with low deposition. We found no trend in the number of bryophyte species. We propose that the decrease of cover and number with low deposition was related to normal ecosystem development (increased shading), suggesting that N deposition maintained or increased the competitiveness of some species in the moderate-deposition region. Deposition had no consistent negative effect on vegetation suggesting that it is less important than normal successional processes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 034
KW - Nitrogen deposition
KW - Vascular plants
KW - Bryophytes
KW - Species richness
KW - Succession
KW - Understorey
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16621
ER -
TY - GEN
A1 - Münch, Juliane
A1 - Abdelilah-Seyfried, Salim
T1 - Sensing and Responding of Cardiomyocytes to Changes of Tissue Stiffness in the Diseased Heart
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Cardiomyocytes are permanently exposed to mechanical stimulation due to cardiac contractility. Passive myocardial stiffness is a crucial factor, which defines the physiological ventricular compliance and volume of diastolic filling with blood. Heart diseases often present with increased myocardial stiffness, for instance when fibrotic changes modify the composition of the cardiac extracellular matrix (ECM). Consequently, the ventricle loses its compliance, and the diastolic blood volume is reduced. Recent advances in the field of cardiac mechanobiology revealed that disease-related environmental stiffness changes cause severe alterations in cardiomyocyte cellular behavior and function. Here, we review the molecular mechanotransduction pathways that enable cardiomyocytes to sense stiffness changes and translate those into an altered gene expression. We will also summarize current knowledge about when myocardial stiffness increases in the diseased heart. Sophisticated in vitro studies revealed functional changes, when cardiomyocytes faced a stiffer matrix. Finally, we will highlight recent studies that described modulations of cardiac stiffness and thus myocardial performance in vivo. Mechanobiology research is just at the cusp of systematic investigations related to mechanical changes in the diseased heart but what is known already makes way for new therapeutic approaches in regenerative biology.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1234
KW - mechanobiology
KW - tissue stiffness
KW - cardiomyocyte
KW - heart regeneration
KW - titin
KW - collagen
KW - agrin
KW - extracellular matrix
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-545805
SN - 1866-8372
ER -
TY - GEN
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
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
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.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1343
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 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-538186
SN - 1866-8372
IS - 1343
SP - 2184
EP - 2199
ER -
TY - GEN
A1 - Stiegler, Jonas
A1 - Kiemel, Katrin
A1 - Eccard, Jana
A1 - Fischer, Christina
A1 - Hering, Robert
A1 - Ortmann, Sylvia
A1 - Strigl, Lea
A1 - Tiedemann, Ralph
T1 - Seed traits matter
BT - Endozoochoric dispersal through a pervasive mobile linker
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali- or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi-natural structures, large fields; complex: high amount of natural and semi-natural structures, small fields) using GPS-based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1229
KW - agricultural landscapes
KW - endozoochory
KW - Lepus europaeus
KW - mobile links
KW - seed dispersal
KW - seed dispersal syndrome
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544265
SN - 1866-8372
SP - 18477
EP - 18491
ER -
TY - GEN
A1 - Eccard, Jana
A1 - Herde, Antje
T1 - Seasonal variation in the behaviour of a short-lived rodent
N2 - Background: Short lived, iteroparous animals in seasonal environments experience variable social and environmental conditions over their lifetime. Animals can be divided into those with a "young-of-the-year" life history (YY, reproducing and dying in the summer of birth) and an "overwinter" life history (OW, overwintering in a subadult state before reproducing next spring).
We investigated how behavioural patterns across the population were affected by season and sex, and whether variation in behaviour reflects the variation in life history patterns of each season. Applications of pace-of-life (POL) theory would suggest that long-lived OW animals are shyer in order to increase survival, and YY are bolder in order to increase reproduction. Therefore, we expected that in winter and spring samples, when only OW can be sampled, the animals should be shyer than in summer and autumn, when both OW and YY animals can be sampled. We studied common vole (Microtus arvalis) populations, which express typical, intra-annual density fluctuation. We captured a total of 492 voles at different months over 3 years and examined boldness and activity level with two standardised behavioural experiments.
Results: Behavioural variables of the two tests were correlated with each other. Boldness, measured as short latencies in both tests, was extremely high in spring compared to other seasons. Activity level was highest in spring and summer, and higher in males than in females.
Conclusion: Being bold in laboratory tests may translate into higher risk-taking in nature by being more mobile while seeking out partners or valuable territories. Possible explanations include asset-protection, with OW animals being rather old with low residual reproductive value in spring. Therefore, OW may take higher risks during this season. Offspring born in spring encounter a lower population density and may have higher reproductive value than offspring of later cohorts. A constant connection between life history and animal personality, as suggested by the POL theory, however, was not found. Nevertheless, correlations of traits suggest the existence of animal personalities. In conclusion, complex patterns of population dynamics, seasonal variation in life histories, and variability of behaviour due to asset-protection may cause complex seasonal behavioural dynamics in a population.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 403
KW - animal personalities
KW - boldness
KW - life history
KW - pace-of-life
KW - POL
KW - phenotypic plasticity
KW - common vole
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-401370
ER -
TY - GEN
A1 - Heinken, Thilo
A1 - von Oheimb, Goddert
A1 - Schmidt, Marcus
A1 - Kriebitzsch, Wolf-Ulrich
A1 - Ellenberg, Hermann
T1 - Schalenwild breitet Gefäßpflanzen in der mitteleuropäischen Kulturlandschaft aus : ein erster Überblick
T1 - The dispersal by hoofed game of vascularplants in the Central European cultural landscape : a first overview
N2 - Im Norddeutschen Tiefland wurde die Ausbreitung von Gefäßpflanzen durch Rehe, Dam- und Rothirsche sowie Wildschweine untersucht. Diese Tiere transportieren zahlreiche Pflanzenarten in teilweise erheblichen Mengen über größere Distanzen, sowohl durch den Kot nach Darmpassage (Endozoochorie) als auch durch Anheftung an Fell und Schalen (Epizoochorie). Besondere Bedeutung kommt dabei Wildschweinen zu, die potenziell fast alle Pflanzenarten ausbreiten können. Bevorzugt werden im Wald wie im Offenland vorkommende Pflanzen und Arten des Offenlands ausgebreitet, während Arten mit enger Waldbindung nur in geringem Maße transportiert werden. Zoochorie durch Schalenwild bietet Erklärungsansätze sowohl für Ausbreitungsphänomene wie auch für das weitgehend fehlende Ausbreitungspotenzial vieler Pflanzenarten. Der Einfluss des Schalenwilds auf die Artenzusammensetzung und Gefäßpflanzen-Diversität in der mitteleuropäischen Kulturlandschaft sollte in seine naturschutzfachliche Neubewertung miteinbezogen werden. Die Einschränkung von Aktionsradien der Tiere durch die Zerschneidung von Lebensräumen sowie die Wildfütterung können für Ausbreitungsprozesse bisher kaum beachtete Konsequenzen haben.
N2 - The dispersal of vascular plants by roe deer, fallow deer, reed deer and wild boar was studied in the lowlands of northern Germany. Hoofed game species transport numerous plant species - partially in large amounts - over relatively long distances, both by faeces after gut passage (endozoochory) and by adhesion to coats and hooves (epizoochory). Wild boar are of particular importance as they potentially disperse almost all plant species. Species occurring both in forests and the open landscape as well as species of the open landscape are preferentially dispersed, while species restricted to forests are only transported to a minor degree. Patterns of zoochory by hoofed game provide explanations for dispersal phenomena and for the low dispersal potential of many plant species. Hoofed game's influence on species composition and phytodiversity in the Central European cultural landscape needs to be re-assessed in terms of its nature conservation relevance. The reduction of home ranges by habitat dissection and the feeding of game animals may have consequences for dispersal processes that have been underestimated until now.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 155
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46522
ER -
TY - GEN
A1 - Schlör, Anja
A1 - Hirschberg, Stefan
A1 - Ben Amor, Ghada
A1 - Meister, Toni Luise
A1 - Arora, Prerna
A1 - Pöhlmann, Stefan
A1 - Hoffmann, Markus
A1 - Pfänder, Stephanie
A1 - Eddin, Omar Kamal
A1 - Kamhieh-Milz, Julian
A1 - Hanack, Katja
T1 - SARS-CoV-2 neutralizing camelid heavy-chain-only antibodies as powerful tools for diagnostic and therapeutic applications
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Introduction: The ongoing COVID-19 pandemic situation caused by SARS-CoV-2 and variants of concern such as B.1.617.2 (Delta) and recently, B.1.1.529 (Omicron) is posing multiple challenges to humanity. The rapid evolution of the virus requires adaptation of diagnostic and therapeutic applications.
Objectives: In this study, we describe camelid heavy-chain-only antibodies (hcAb) as useful tools for novel in vitro diagnostic assays and for therapeutic applications due to their neutralizing capacity.
Methods: Five antibody candidates were selected out of a naïve camelid library by phage display and expressed as full length IgG2 antibodies. The antibodies were characterized by Western blot, enzyme-linked immunosorbent assays, surface plasmon resonance with regard to their specificity to the recombinant SARS-CoV-2 Spike protein and to SARS-CoV-2 virus-like particles. Neutralization assays were performed with authentic SARS-CoV-2 and pseudotyped viruses (wildtype and Omicron).
Results: All antibodies efficiently detect recombinant SARS-CoV-2 Spike protein and SARS-CoV-2 virus-like particles in different ELISA setups. The best combination was shown with hcAb B10 as catcher antibody and HRP-conjugated hcAb A7.2 as the detection antibody. Further, four out of five antibodies potently neutralized authentic wildtype SARS-CoV-2 and particles pseudotyped with the SARS-CoV-2 Spike proteins of the wildtype and Omicron variant, sublineage BA.1 at concentrations between 0.1 and 0.35 ng/mL (ND50).
Conclusion: Collectively, we report novel camelid hcAbs suitable for diagnostics and potential therapy.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1280
KW - camelid heavy-chain-only antibodies
KW - single domain antibodies
KW - nanobodies
KW - SARS-CoV-2
KW - neutralization
KW - Omicron
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-570124
SN - 1866-8372
IS - 1280
ER -
TY - GEN
A1 - Heinken, Thilo
T1 - Sand- und Silikat-Kiefernwälder (Dicrano-Pinion) in Deutschland : Gliederungskonzept und Ökologie
T1 - Pine forests on sandy and silicate soils (Dicrano-Pinion) in Germany : classification concept and ecology
N2 - In preparation for the „Synopsis of plant communities of Germany“ a comprehensive classification concept for the Scots pine forests on sandy and silicate soils is presented. On the basis of 2699 relevés from all natural provinces with important occurrences this classification for the first time integrates both northern and southern German forest stands. Pine forests are stable (“climax”) communities on three distinct habitat types at the drought and wetness limits of forest growth. In the phytosociological system these are reflected by the clearly separated syntaxa Erico-Pinetea (dry-calcareous), Dicrano-Pinion (dry-acidic) and Vaccinio uliginosi- Pinetea (wet-acidic). However, Pulsatillo-Pinetea (dry-moderate basicity) described in earlier publications cannot be separated floristically. In addition to the stable communities on extreme habitats pine forests of the mentioned syntaxa are widespread on potential mixed deciduous forest stands, especially after anthropogenic devastation and even beyond their original range. Six communites of the Dicrano-Pinion which also includes such secondary pine forest stands are occurring in Germany. They are presented in detail and classified according to their dynamic and edaphic differentiation. Lichen-rich pine forests (Cladonio- Pinetum) which grow on extremely dry and nutrient-poor sites are ecologically and floristically well-defined, though closely connected with other Dicrano-Pinion communities by forest succession. After separation of the Cladonio-Pinetum the Leucobryo-Pinetum is a speciespoor “central association” within the alliance. The Deschampsia flexuosa-Pinus-sylvestriscommunity is the most widespread forest type and dynamically and floristically passes into the mixed oak forests on acidic soils (Quercion roboris). On base-rich habitats the Empetro- Pinetum as endemic community of the southern Baltic Sea coasts, and the Peucedano-Pinetum in the northeastern and southern German inland are distinguished. The latter is found both on calcareous sands and primarily acidic sands which are secondary limed by calciferous pollutions. Finally, differences and similarities between the geographically separated northern and southern German Dicrano-Pinion forests are discussed in a biogeographic context, emphasising the advantages of the presented nation-wide classification concept.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 154
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46518
ER -
TY - GEN
A1 - Kugler, Annette
A1 - Köhler, Barbara
A1 - Palme, Klaus
A1 - Wolff, Patricia
A1 - Dietrich, Petra
T1 - Salt-dependent regulation of a CNG channel subfamily in Arabidopsis
N2 - Background: In Arabidopsis thaliana, the family of cyclic nucleotide-gated channels (CNGCs) is composed of 20 members. Previous studies indicate that plant CNGCs are involved in the control of growth processes and responses to abiotic and biotic stresses. According to their proposed function as cation entry pathways these channels contribute to cellular cation homeostasis, including calcium and sodium, as well as to stress-related signal transduction. Here, we studied the expression patterns and regulation of CNGC19 and CNGC20, which constitute one of the five CNGC subfamilies. Results: GUS, GFP and luciferase reporter assays were used to study the expression of CNGC19 and CNGC20 genes from Arabidopsis thaliana in response to developmental cues and salt stress. CNGC19 and CNGC20 were differentially expressed in roots and shoots. The CNGC19 gene was predominantly active in roots already at early growth stages. Major expression was observed in the phloem. CNGC20 showed highest promoter activity in mesophyll cells surrounding the veins. Its expression increased during development and was maximal in mature and senescent leaves. Both genes were upregulated in the shoot in response to elevated NaCl but not mannitol concentrations. While in the root, CNGC19 did not respond to changes in the salt concentration, in the shoot it was strongly upregulated in the observed time frame (6-72 hours). Salt-induction of CNGC20 was also observed in the shoot, starting already one hour after stress treatment. It occurred with similar kinetics, irrespective of whether NaCl was applied to roots of intact plants or to the petiole of detached leaves. No differences in K and Na contents of the shoots were measured in homozygous T-DNA insertion lines for CNGC19 and CNGC20, respectively, which developed a growth phenotype in the presence of up to 75 mM NaCl similar to that of the wild type. Conclusion: Together, the results strongly suggest that both channels are involved in the salinity response of different cell types in the shoot. Upon salinity both genes are upregulated within hours. CNGC19 and CNGC20 could assist the plant to cope with toxic effects caused by salt stress, probably by contributing to a re-allocation of sodium within the plant.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 133
KW - Nucleotide-gated channel
KW - Na+/H+ antiporter SOS1
KW - Ricinus-communis l
KW - Plasma membrane
KW - Functional analysis
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45019
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 - 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 - Breedveld, Merel Cathelijne
A1 - Folkertsma, Remco
A1 - Eccard, Jana
T1 - Rodent mothers increase vigilance behaviour when facing infanticide risk
T2 - Postprints der Universität Potsdam Mathematisch- Naturwissenschaftliche Reihe
N2 - Infanticide, the killing of unrelated young, is widespread and frequently driven by sexual conflict. especially in mammals with exclusive maternal care, infanticide by males is common and females suffer fitness costs. Recognizing infanticide risk and adjusting offspring protection accordingly should therefore be adaptive in female mammals. Using a small mammal (Myodes glareolus) in outdoor enclosures, we investigated whether lactating mothers adjust offspring protection, and potential mate search behaviour, in response to different infanticide risk levels. We presented the scent of the litter’s sire or of a stranger male near the female’s nest, and observed female nest presence and movement by radiotracking. While both scents simulated a mating opportunity, they represented lower (sire) and higher (stranger) infanticide risk. compared to the sire treatment, females in the stranger treatment left their nest more often, showed increased activity and stayed closer to the nest, suggesting offspring protection from outside the nest through elevated alertness and vigilance. females with larger litters spent more time investigating scents and used more space in the sire but not in the stranger treatment. Thus, current investment size affected odour inspection and resource acquisition under higher risk. Adjusting nest protection and resource acquisition to infanticide risk could allow mothers to elicit appropriate (fitness-saving) counterstrategies, and thus, may be widespread.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 766
KW - vole clethrionomys-glareolus
KW - male bank voles
KW - maternal aggression
KW - reproductive strategies
KW - offspring-defense
KW - myodes-glareolus
KW - predation risk
KW - prairie vole
KW - recognition
KW - costs
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-438074
SN - 1866-8372
IS - 766
ER -
TY - GEN
A1 - de Castro, Francisco
A1 - Gaedke, Ursula
A1 - Boenigk, Jens
T1 - Reverse evolution : driving forces behind the loss of acquired photosynthetic traits
N2 - Background: The loss of photosynthesis has occurred often in eukaryotic evolution, even more than its acquisition, which occurred at least nine times independently and which generated the evolution of the supergroups Archaeplastida, Rhizaria, Chromalveolata and Excavata. This secondary loss of autotrophic capability is essential to explain the evolution of eukaryotes and the high diversity of protists, which has been severely underestimated until recently. However, the ecological and evolutionary scenarios behind this evolutionary ‘‘step back’’ are still largely unknown. Methodology/Principal Findings: Using a dynamic model of heterotrophic and mixotrophic flagellates and two types of prey, large bacteria and ultramicrobacteria, we examine the influence of DOC concentration, mixotroph’s photosynthetic growth rate, and external limitations of photosynthesis on the coexistence of both types of flagellates. Our key premises are: large bacteria grow faster than small ones at high DOC concentrations, and vice versa; and heterotrophic flagellates are more efficient than the mixotrophs grazing small bacteria (both empirically supported). We show that differential efficiency in bacteria grazing, which strongly depends on cell size, is a key factor to explain the loss of photosynthesis in mixotrophs (which combine photosynthesis and bacterivory) leading to purely heterotrophic lineages. Further, we show in what conditions an heterotroph mutant can coexist, or even out-compete, its mixotrophic ancestor, suggesting that bacterivory and cell size reduction may have been major triggers for the diversification of eukaryotes. Conclusions/Significance: Our results suggest that, provided the mixotroph’s photosynthetic advantage is not too large, the (small) heterotroph will also dominate in nutrient-poor environments and will readily invade a community of mixotrophs and bacteria, due to its higher efficiency exploiting the ultramicrobacteria. As carbon-limited conditions were presumably widespread throughout Earth history, such a scenario may explain the numerous transitions from phototrophy to mixotrophy and further to heterotrophy within virtually all major algal lineages. We challenge prevailing concepts that affiliated the evolution of phagotrophy with eutrophic or strongly light-limited environments only.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 128
KW - Fresh-water habitats
KW - Operon copy number
KW - Growth-rate
KW - Bacteria
KW - Plankton
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44968
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 - GEN
A1 - Köchy, Martin
A1 - Mathaj, Martin
A1 - Jeltsch, Florian
A1 - Malkinson, Dan
T1 - Resilience of stocking capacity to changing climate in arid to Mediterranean landscapes
N2 - Small livestock is an important resource for rural human populations in dry climates. How strongly will climate change affect the capacity of the rangeland? We used hierarchical modelling to scale quantitatively the growth of shrubs and annual plants, the main food of sheep and goats, to the landscape extent in the eastern Mediterranean region. Without grazing, productivity increased in a sigmoid way with mean annual precipitation. Grazing reduced productivity more strongly the drier the landscape. At a point just under the stocking capacity of the vegetation, productivity declined precipitously with more intense grazing due to a lack of seed production of annuals. We repeated simulations with precipitation patterns projected by two contrasting IPCC scenarios. Compared to results based on historic patterns, productivity and stocking capacity did not differ in most cases. Thus, grazing intensity remains the stronger impact on landscape productivity in this dry region even in the future.
N2 - Kleinvieh ist eine wichtige Lebensgrundlage für die Landbevölkerung in trockenen Regionen. Wie stark wird sich der Klimawandel auf die Tragfähigkeit der Weideflächen auswirken? Wir benutzten hierarchische Modellierung, um das Wachstum von Sträuchern und einjährigen Kräutern, das wichtigste Futter für Ziegen und Schafe, quantitativ auf die Fläche von Landschaften in der östlichen Mittelmeerregion zu dimensionieren. Die Produktivität ohne Beweidung stieg sigmoidal mit dem mittleren Jahresniederschlag. Je trockener die Landschaft, desto stärker verminderte Beweidung die Produktion. An einem Punkt knapp unter der Tragfähigkeit der Vegetation, sank die Produktion stark mit zunehmender Beweidung, weil die Samenproduktion der Kräuter zu gering war. Wir wiederholten die Simulationen mit Niederschlagsverteilungsmustern gemäß zweier gegensätzlicher IPCC-Szenarien. Zukünftige Produktivität und Tragfähigkeit unterschieden sich in den meisten Fällen nicht von Ergebnissen auf Grund von historischer Niederschlagsverteilung. Allerdings war die zukünftige Produktivität in trockenen Habitaten der semiariden und trocken-mediterranen Regionen niedriger. Somit hat auch in Zukunft die Besatzdichte die größere Auswirkung auf die Produktivität dieser trockenen Landschaft als das Klima. "This abstract is provided by the authors, and is for convenience of the users only. The author certifies that the translation faithfully represents the official version in the language of the journal, which is the published Abstract of record and is the only Abstract to be used for reference and citation."
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 066
KW - topography
KW - spatially explicit model
KW - climate change
KW - Middle East
KW - stocking capacity
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18720
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 - GEN
A1 - Huynen, Leon
A1 - Suzuki, Takayuki
A1 - Ogura, Toshihiko
A1 - Watanabe, Yusuke
A1 - Millar, Craig D.
A1 - Hofreiter, Michael
A1 - Smith, Craig
A1 - Mirmoeini, Sara
A1 - Lambert, David M.
T1 - Reconstruction and in vivo analysis of the extinct tbx5 gene from ancient wingless moa (Aves: Dinornithiformes)
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
The forelimb-specific gene tbx5 is highly conserved and essential for the development of forelimbs in zebrafish, mice, and humans. Amongst birds, a single order, Dinornithiformes, comprising the extinct wingless moa of New Zealand, are unique in having no skeletal evidence of forelimb-like structures.
Results
To determine the sequence of tbx5 in moa, we used a range of PCR-based techniques on ancient DNA to retrieve all nine tbx5 exons and splice sites from the giant moa, Dinornis. Moa Tbx5 is identical to chicken Tbx5 in being able to activate the downstream promotors of fgf10 and ANF. In addition we show that missexpression of moa tbx5 in the hindlimb of chicken embryos results in the formation of forelimb features, suggesting that Tbx5 was fully functional in wingless moa. An alternatively spliced exon 1 for tbx5 that is expressed specifically in the forelimb region was shown to be almost identical between moa and ostrich, suggesting that, as well as being fully functional, tbx5 is likely to have been expressed normally in moa since divergence from their flighted ancestors, approximately 60 mya.
Conclusions
The results suggests that, as in mice, moa tbx5 is necessary for the induction of forelimbs, but is not sufficient for their outgrowth. Moa Tbx5 may have played an important role in the development of moa’s remnant forelimb girdle, and may be required for the formation of this structure. Our results further show that genetic changes affecting genes other than tbx5 must be responsible for the complete loss of forelimbs in moa.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1117
KW - tbx5
KW - Moa
KW - gene expression
KW - ancient DNA
KW - development
KW - forelimb
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431599
SN - 1866-8372
IS - 1117
ER -
TY - GEN
A1 - Malchow, Anne-Kathleen
A1 - Bocedi, Greta
A1 - Palmer, Stephen C. F.
A1 - Travis, Justin M. J.
A1 - Zurell, Damaris
T1 - RangeShiftR: an R package for individual-based simulation of spatial eco-evolutionary dynamics and speciesu0027 responses to environmental changes
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Reliably modelling the demographic and distributional responses of a species to environmental changes can be crucial for successful conservation and management planning. Process-based models have the potential to achieve this goal, but so far they remain underused for predictions of species' distributions. Individual-based models offer the additional capability to model inter-individual variation and evolutionary dynamics and thus capture adaptive responses to environmental change. We present RangeShiftR, an R implementation of a flexible individual-based modelling platform which simulates eco-evolutionary dynamics in a spatially explicit way. The package provides flexible and fast simulations by making the software RangeShifter available for the widely used statistical programming platform R. The package features additional auxiliary functions to support model specification and analysis of results. We provide an outline of the package's functionality, describe the underlying model structure with its main components and present a short example. RangeShiftR offers substantial model complexity, especially for the demographic and dispersal processes. It comes with elaborate tutorials and comprehensive documentation to facilitate learning the software and provide help at all levels. As the core code is implemented in C++, the computations are fast. The complete source code is published under a public licence, making adaptations and contributions feasible. The RangeShiftR package facilitates the application of individual-based and mechanistic modelling to eco-evolutionary questions by operating a flexible and powerful simulation model from R. It allows effortless interoperation with existing packages to create streamlined workflows that can include data preparation, integrated model specification and results analysis. Moreover, the implementation in R strengthens the potential for coupling RangeShiftR with other models.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1178
KW - connectivity
KW - conservation
KW - dispersal
KW - evolution
KW - population dynamics
KW - range dynamics
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-523979
SN - 1866-8372
IS - 10
ER -
TY - GEN
A1 - Meyer, Rhonda Christiane
A1 - Kusterer, Barbara
A1 - Lisec, Jan
A1 - Steinfath, Matthias
A1 - Becher, Martina
A1 - Scharr, Hanno
A1 - Melchinger, Albrecht E.
A1 - Selbig, Joachim
A1 - Schurr, Ulrich
A1 - Willmitzer, Lothar
A1 - Altmann, Thomas
T1 - QTL analysis of early stage heterosis for biomass in Arabidopsis
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - The main objective of this study was to identify genomic regions involved in biomass heterosis using QTL, generation means, and mode-of-inheritance classification analyses. In a modified North Carolina Design III we backcrossed 429 recombinant inbred line and 140 introgression line populations to the two parental accessions, C24 and Col-0, whose F 1 hybrid exhibited 44% heterosis for biomass. Mid-parent heterosis in the RILs ranged from −31 to 99% for dry weight and from −58 to 143% for leaf area. We detected ten genomic positions involved in biomass heterosis at an early developmental stage, individually explaining between 2.4 and 15.7% of the phenotypic variation. While overdominant gene action was prevalent in heterotic QTL, our results suggest that a combination of dominance, overdominance and epistasis is involved in biomass heterosis in this Arabidopsis cross.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1330
KW - Quantitative Trait Locus
KW - recombinant inbred line
KW - Quantitative Trait Locus analysis
KW - dominance effect
KW - recombinant inbred line population
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431272
SN - 1866-8372
IS - 1330
ER -
TY - GEN
A1 - Reil, Daniela
A1 - Rosenfeld, Ulrike
A1 - Imholt, Christian
A1 - Schmidt, Sabrina
A1 - Ulrich, Rainer G.
A1 - Eccard, Jana
A1 - Jacob, Jens
T1 - Puumala hantavirus infections in bank vole populations
BT - host and virus dynamics in Central Europe
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
In Europe, bank voles (Myodes glareolus) are widely distributed and can transmit Puumala virus (PUUV) to humans, which causes a mild to moderate form of haemorrhagic fever with renal syndrome, called nephropathia epidemica. Uncovering the link between host and virus dynamics can help to prevent human PUUV infections in the future. Bank voles were live trapped three times a year in 2010–2013 in three woodland plots in each of four regions in Germany. Bank vole population density was estimated and blood samples collected to detect PUUV specific antibodies.
Results
We demonstrated that fluctuation of PUUV seroprevalence is dependent not only on multi-annual but also on seasonal dynamics of rodent host abundance. Moreover, PUUV infection might affect host fitness, because seropositive individuals survived better from spring to summer than uninfected bank voles. Individual space use was independent of PUUV infections.
Conclusions
Our study provides robust estimations of relevant patterns and processes of the dynamics of PUUV and its rodent host in Central Europe, which are highly important for the future development of predictive models for human hantavirus infection risk.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 957
KW - Myodes glareolus
KW - population dynamics
KW - Puumala virus seroprevalence
KW - space use
KW - survival
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431232
SN - 1866-8372
IS - 957
ER -
TY - GEN
A1 - Steinfath, Matthias
A1 - Gärtner, Tanja
A1 - Lisec, Jan
A1 - Meyer, Rhonda C.
A1 - Altmann, Thomas
A1 - Willmitzer, Lothar
A1 - Selbig, Joachim
T1 - Prediction of hybrid biomass in Arabidopsis thaliana by selected parental SNP and metabolic markers
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - A recombinant inbred line (RIL) population, derived from two Arabidopsis thaliana accessions, and the corresponding testcrosses with these two original accessions were used for the development and validation of machine learning models to predict the biomass of hybrids. Genetic and metabolic information of the RILs served as predictors. Feature selection reduced the number of variables (genetic and metabolic markers) in the models by more than 80% without impairing the predictive power. Thus, potential biomarkers have been revealed. Metabolites were shown to bear information on inherited macroscopic phenotypes. This proof of concept could be interesting for breeders. The example population exhibits substantial mid-parent biomass heterosis. The results of feature selection could therefore be used to shed light on the origin of heterosis. In this respect, mainly dominance effects were detected.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1324
KW - Quantitative Trait Locus
KW - feature selection
KW - Partial Little Square
KW - recombinant inbred line
KW - Quantitative Trait Locus analysis
Y1 - 2009
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431115
SN - 1866-8372
IS - 1324
ER -
TY - GEN
A1 - Bierbach, David
A1 - Schulte, Matthias
A1 - Herrmann, Nina
A1 - Tobler, Michael
A1 - Stadler, Stefan
A1 - Jung, Christian T.
A1 - Kunkel, Benjamin
A1 - Riesch, Rüdiger
A1 - Klaus, Sebastian
A1 - Ziege, Madlen
A1 - Indy, Jeane Rimber
A1 - Arias-Rodriguez, Lenin
A1 - Plath, Martin
T1 - Predator-induced changes of female mating preferences
BT - innate and experiential effects
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators.
Results
In dichotomous choice tests predator-naïve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey.
Conclusions
Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 984
KW - sexual selection
KW - female choice
KW - non-independent mate choice
KW - predator recognition
KW - Poecilia mexicana
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431099
SN - 1866-8372
IS - 984
ER -
TY - GEN
A1 - Wacker, Alexander
A1 - von Elert, Eric
T1 - Polyunsaturated fatty acids : evidence for non-substitutable biochemical resources in Daphnia galeata
N2 - The factors that determine the efficiency of energy transfer in aquatic food webs have been investigated for many decades. The plant-animal interface is the most variable and least predictable of all levels in the food web. In order to study determinants of food quality in a large lake and to test the recently proposed central importance of the long-chained eicosapentaenoic acid (EPA) at the pelagic producer-grazer interface, we tested the importance of polyunsaturated fatty acids (PUFAs) at the pelagic producerconsumer interface by correlating sestonic food parameters with somatic growth rates of a clone of Daphnia galeata. Daphnia growth rates were obtained from standardized laboratory experiments spanning one season with Daphnia feeding on natural seston from Lake Constance, a large pre-alpine lake. Somatic growth rates were fitted to sestonic parameters by using a saturation function. A moderate amount of variation was explained when the model included the elemental parameters carbon (r2 = 0.6) and nitrogen (r2 = 0.71). A tighter fit was obtained when sestonic phosphorus was incorporated (r2 = 0.86). The nonlinear regression with EPA was relatively weak (r2 = 0.77), whereas the highest degree of variance was explained by three C18-PUFAs. The best (r2 = 0.95), and only significant, correlation of Daphnia's growth was found with the C18-PUFA α-linolenic acid (α-LA; C18:3n-3). This correlation was weakest in late August when C:P values increased to 300, suggesting that mineral and PUFA-limitation of Daphnia's growth changed seasonally. Sestonic phosphorus and some PUFAs showed not only tight correlations with growth, but also with sestonic α-LA content. We computed Monte Carlo simulations to test whether the observed effects of α-LA on growth could be accounted for by EPA, phosphorus, or one of the two C18-PUFAs, stearidonic acid (C18:4n-3) and linoleic acid (C18:2n-6). With >99 % probability, the correlation of growth with α-LA could not be explained by any of these parameters. In order to test for EPA limitation of Daphnia's growth, in parallel with experiments on pure seston, growth was determined on seston supplemented with chemostat-grown, P-limited Stephanodiscus hantzschii, which is rich in EPA. Although supplementation increased the EPA content 80-800x, no significant changes in the nonlinear regression of the growth rates with α-LA were found, indicating that growth of Daphnia on pure seston was not EPA limited. This indicates that the two fatty acids, EPA and α-LA, were not mutually substitutable biochemical resources and points to different physiological functions of these two PUFAs. These results support the PUFA-limitation hypothesis for sestonic C:P < 300 but are contrary to the hypothesis of a general importance of EPA, since no evidence for EPA limitation was found. It is suggested that the resource ratios of EPA and α-LA rather than the absolute concentrations determine which of the two resources is limiting growth.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 063
KW - alga
KW - consumer
KW - Daphnia
KW - fatty acid
KW - food quality
KW - grazer
KW - herbivore
KW - Lake Constance
KW - European Alps
KW - PUFA
KW - seston
Y1 - 2001
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17587
ER -
TY - GEN
A1 - Bergholz, Kolja
A1 - Sittel, Lara-Pauline
A1 - Ristow, Michael
A1 - Jeltsch, Florian
A1 - Weiß, Lina
T1 - Pollinator guilds respond contrastingly at different scales to landscape parameters of land-use intensity
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Land-use intensification is the main factor for the catastrophic decline of insect pollinators. However, land-use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land-use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60–3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140–400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500–3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land-use intensification seem to be highly landscape-specific.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1298
KW - hoverflies
KW - landscape homogenization
KW - plant functional trait
KW - syrphids
KW - wild bees
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-577307
SN - 1866-8372
IS - 1298
ER -
TY - GEN
A1 - Lukan, Tjaša
A1 - Machens, Fabian
A1 - Coll, Anna
A1 - Baebler, Špela
A1 - Messerschmidt, Katrin
A1 - Gruden, Kristina
T1 - Plant X-tender
BT - an extension of the AssemblX system for the assembly and expression of multigene constructs in plants
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Cloning multiple DNA fragments for delivery of several genes of interest into the plant genome is one of the main technological challenges in plant synthetic biology. Despite several modular assembly methods developed in recent years, the plant biotechnology community has not widely adopted them yet, probably due to the lack of appropriate vectors and software tools. Here we present Plant X-tender, an extension of the highly efficient, scarfree and sequence-independent multigene assembly strategy AssemblX,based on overlapdepended cloning methods and rare-cutting restriction enzymes. Plant X-tender consists of a set of plant expression vectors and the protocols for most efficient cloning into the novel vector set needed for plant expression and thus introduces advantages of AssemblX into plant synthetic biology. The novel vector set covers different backbones and selection markers to allow full design flexibility. We have included ccdB counterselection, thereby allowing the transfer of multigene constructs into the novel vector set in a straightforward and highly efficient way. Vectors are available as empty backbones and are fully flexible regarding the orientation of expression cassettes and addition of linkers between them, if required. We optimised the assembly and subcloning protocol by testing different scar-less assembly approaches: the noncommercial SLiCE and TAR methods and the commercial Gibson assembly and NEBuilder HiFi DNA assembly kits. Plant X-tender was applicable even in combination with low efficient homemade chemically competent or electrocompetent Escherichia coli. We have further validated the developed procedure for plant protein expression by cloning two cassettes into the newly developed vectors and subsequently transferred them to Nicotiana benthamiana in a transient expression setup. Thereby we show that multigene constructs can be delivered into plant cells in a streamlined and highly efficient way. Our results will support faster introduction of synthetic biology into plant science.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 990
KW - ligation cloning extract
KW - DNA cloning
KW - synthetic biology
KW - multiple genes
KW - vector system
KW - transformation
KW - recombination
KW - protein
KW - RNA
KW - Methylation
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446281
SN - 1866-8372
IS - 990
ER -
TY - GEN
A1 - Möser, Christin
A1 - Lorenz, Jessica S.
A1 - Sajfutdinow, Martin
A1 - Smith, David M.
T1 - Pinpointed stimulation of EphA2 receptors via DNA-templated oligovalence
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - DNA nanostructures enable the attachment of functional molecules to nearly any unique location on their underlying structure. Due to their single-base-pair structural resolution, several ligands can be spatially arranged and closely controlled according to the geometry of their desired target, resulting in optimized binding and/or signaling interactions. Here, the efficacy of SWL, an ephrin-mimicking peptide that binds specifically to EphrinA2 (EphA2) receptors, increased by presenting up to three of these peptides on small DNA nanostructures in an oligovalent manner. Ephrin signaling pathways play crucial roles in tumor development and progression. Moreover, Eph receptors are potential targets in cancer diagnosis and treatment. Here, the quantitative impact of SWL valency on binding, phosphorylation (key player for activation) and phenotype regulation in EphA2-expressing prostate cancer cells was demonstrated. EphA2 phosphorylation was significantly increased by DNA trimers carrying three SWL peptides compared to monovalent SWL. In comparison to one of EphA2’s natural ligands ephrin-A1, which is known to bind promiscuously to multiple receptors, pinpointed targeting of EphA2 by oligovalent DNA-SWL constructs showed enhanced cell retraction. Overall, we show that DNA scaffolds can increase the potency of weak signaling peptides through oligovalent presentation and serve as potential tools for examination of complex signaling pathways.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1041
KW - DNA nanostructure
KW - ephrin
KW - EphA2
KW - SWL
KW - PC-3 cells
KW - multivalence
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468828
SN - 1866-8372
IS - 1041
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 - GEN
A1 - Kahl, Sandra
A1 - Kappel, Christian
A1 - Joshi, Jasmin Radha
A1 - Lenhard, Michael
T1 - Phylogeography of a widely distributed plant species reveals cryptic genetic lineages with parallel phenotypic responses to warming and drought conditions
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - To predict how widely distributed species will perform under future climate change, it is crucial to understand and reveal their underlying phylogenetics. However, detailed information about plant adaptation and its genetic basis and history remains scarce and especially widely distributed species receive little attention despite their putatively high adaptability.
To examine the adaptation potential of a widely distributed species, we sampled the model plant Silene vulgaris across Europe. In a greenhouse experiment, we exposed the offspring of these populations to a climate change scenario for central Europe and revealed the population structure through whole-genome sequencing. Plants were grown under two temperatures (18°C and 21°C) and three precipitation regimes (65, 75, and 90 mm) to measure their response in biomass and fecundity-related traits. To reveal the population genetic structure, ddRAD sequencing was employed for a whole-genome approach. We found three major genetic clusters in S. vulgaris from Europe: one cluster comprising Southern European populations, one cluster of Western European populations, and another cluster containing central European populations. Population genetic diversity decreased with increasing latitude, and a Mantel test revealed significant correlations between FST and geographic distances as well as between genetic and environmental distances. Our trait analysis showed that the genetic clusters significantly differed in biomass-related traits and in the days to flowering. However, half of the traits showed parallel response patterns to the experimental climate change scenario. Due to the differentiated but parallel response patterns, we assume that phenotypic plasticity plays an important role for the adaptation of the widely distributed species S. vulgaris and its intraspecific genetic lineages.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1218
KW - climate adaptation
KW - ddRAD
KW - Silene vulgaris
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-530035
SN - 1866-8372
SP - 13986
EP - 14002
ER -
TY - GEN
A1 - Rainford, James L.
A1 - Hofreiter, Michael
A1 - Mayhew, Peter J.
T1 - Phylogenetic analyses suggest that diversification and body size evolution are independent in insects
T2 - BMC evolutionary biology
N2 - Background:
Skewed body size distributions and the high relative richness of small-bodied taxa are a fundamental
property of a wide range of animal clades. The evolutionary processes responsible for generating these distributions
are well described in vertebrate model systems but have yet to be explored in detail for other major terrestrial
clades. In this study, we explore the macro-evolutionary patterns of body size variation across families of Hexapoda
(insects and their close relatives), using recent advances in phylogenetic understanding, with an aim to investigate
the link between size and diversity within this ancient and highly diverse lineage.
Results:
The maximum, minimum and mean-log body lengths of hexapod families are all approximately log-normally
distributed, consistent with previous studies at lower taxonomic levels, and contrasting with skewed distributions
typical of vertebrate groups. After taking phylogeny and within-tip variation into account, we find no evidence for a
negative relationship between diversification rate and body size, suggesting decoupling of the forces controlling these
two traits. Likelihood-based modeling of the log-mean body size identifies distinct processes operating within
Holometabola and Diptera compared with other hexapod groups, consistent with accelerating rates of size evolution
within these clades, while as a whole, hexapod body size evolution is found to be dominated by neutral processes
including significant phylogenetic conservatism.
Conclusions:
Based on our findings we suggest that the use of models derived from well-studied but atypical clades,
such as vertebrates may lead to misleading conclusions when applied to other major terrestrial lineages. Our results
indicate that within hexapods, and within the limits of current systematic and phylogenetic knowledge, insect
diversification is generally unfettered by size-biased macro-evolutionary processes, and that these processes over large
timescales tend to converge on apparently neutral evolutionary processes. We also identify limitations on available
data within the clade and modeling approaches for the resolution of trees of higher taxa, the resolution of which may
collectively enhance our understanding of this key component of terrestrial ecosystems.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 441
KW - body size
KW - diversification
KW - hexapoda
KW - insects
KW - phylogeny
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407328
ER -
TY - GEN
A1 - Clegg, Mark R.
A1 - Wacker, Alexander
A1 - Spijkerman, Elly
T1 - Phenotypic Diversity and Plasticity of Photoresponse Across an Environmentally Contrasting Family of Phytoflagellates
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Organisms often employ ecophysiological strategies to exploit environmental conditions and ensure bio-energetic success. However, the many complexities involved in the differential expression and flexibility of these strategies are rarely fully understood. Therefore, for the first time, using a three-part cross-disciplinary laboratory experimental analysis, we investigated the diversity and plasticity of photoresponsive traits employed by one family of environmentally contrasting, ecologically important phytoflagellates. The results demonstrated an extensive inter-species phenotypic diversity of behavioural, physiological, and compositional photoresponse across the Chlamydomonadaceae, and a multifaceted intra-species phenotypic plasticity, involving a broad range of beneficial photoacclimation strategies, often attributable to environmental predisposition and phylogenetic differentiation. Deceptively diverse and sophisticated strong (population and individual cell) behavioural photoresponses were observed, with divergence from a general preference for low light (and flexibility) dictated by intra-familial differences in typical habitat (salinity and trophy) and phylogeny. Notably, contrasting lower, narrow, and flexible compared with higher, broad, and stable preferences were observed in freshwater vs. brackish and marine species. Complex diversity and plasticity in physiological and compositional photoresponses were also discovered. Metabolic characteristics (such as growth rates, respiratory costs and photosynthetic capacity, efficiency, compensation and saturation points) varied elaborately with species, typical habitat (often varying more in eutrophic species, such as Chlamydomonas reinhardtii), and culture irradiance (adjusting to optimise energy acquisition and suggesting some propensity for low light). Considerable variations in intracellular pigment and biochemical composition were also recorded. Photosynthetic and accessory pigments (such as chlorophyll a, xanthophyll-cycle components, chlorophyll a:b and chlorophyll a:carotenoid ratios, fatty acid content and saturation ratios) varied with phylogeny and typical habitat (to attune photosystem ratios in different trophic conditions and to optimise shade adaptation, photoprotection, and thylakoid architecture, particularly in freshwater environments), and changed with irradiance (as reaction and harvesting centres adjusted to modulate absorption and quantum yield). The complex, concomitant nature of the results also advocated an integrative approach in future investigations. Overall, these nuanced, diverse, and flexible photoresponsive traits will greatly contribute to the functional ecology of these organisms, addressing environmental heterogeneity and potentially shaping individual fitness, spatial and temporal distribution, prevalence, and ecosystem dynamics.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1219
KW - photoresponse
KW - behaviour
KW - physiology
KW - composition
KW - photosynthesis
KW - acclimation
KW - Chlamydomonas
KW - ecophysiology
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-536174
SN - 1866-8372
IS - 1219
ER -
TY - GEN
A1 - Blenau, Wolfgang
A1 - Troppmann, Britta
A1 - Walz, Bernd
T1 - Pharmacology of serotonin-induced salivary secretion in Periplaneta americana
N2 - The acinar salivary gland of the cockroach, Periplaneta americana, is innervated by dopaminergic and serotonergic nerve fibers. Stimulation of the glands by serotonin (5-hydroxytryptamine, 5-HT) results in the production of a protein-rich saliva, whereas stimulation by dopamine results in saliva that is protein-free. Thus, dopamine acts selectively on ion-transporting peripheral cells within the acini, and 5-HT acts on protein-producing central cells. We have investigated the pharmacology of the 5-HT-induced secretory activity of isolated salivary glands of P. americana by testing several 5-HT receptor agonists and antagonists. The effects of 5-HT can be mimicked by the non-selective 5-HT receptor agonist 5-methoxytryptamine. All tested agonists that display at least some receptor subtype specificity in mammals, i.e., 5-carboxamidotryptamine, (+/-)-8-OH-DPAT, (+/-)-DOI, and AS 19, were ineffective in stimulating salivary secretion. 5-HT-induced secretion can be blocked by the vertebrate 5-HT receptor antagonists methiothepin, cyproheptadine, and mianserin. Our pharmacological data indicate that the pharmacology of arthropod 5-HT receptors is remarkably different from that of their vertebrate counterparts. (C) 2007 Elsevier Ltd. All rights reserved.
KW - Biogenic amine
KW - G protein-coupled receptor
KW - insect
KW - salivary gland
KW - secretion
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44319
ER -
TY - GEN
A1 - Stiegler, Jonas
A1 - Lins, Alisa
A1 - Dammhahn, Melanie
A1 - Kramer-Schadt, Stephanie
A1 - Ortmann, Sylvia
A1 - Blaum, Niels
T1 - Personality drives activity and space use in a mammalian herbivore
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum.
Methods
We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals’ degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population.
Results
We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant).
Conclusions
Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1299
KW - Animal personality
KW - Movement ecology
KW - Inter-individual differences
KW - ODBA
KW - Energy expenditure
KW - European hare
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-577327
SN - 1866-8372
SP - 1
EP - 12
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - GEN
A1 - Sullivan, Mitchell A.
A1 - Nitschke, Silvia
A1 - Steup, Martin
A1 - Minassian, Berge A.
A1 - Nitschke, Felix
T1 - Pathogenesis of Lafora disease
BT - transition of soluble glycogen to insoluble polyglucosan
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Lafora disease (LD, OMIM #254780) is a rare, recessively inherited neurodegenerative disease with adolescent onset, resulting in progressive myoclonus epilepsy which is fatal usually within ten years of symptom onset. The disease is caused by loss-of-function mutations in either of the two genes EPM2A (laforin) or EPM2B (malin). It characteristically involves the accumulation of insoluble glycogen-derived particles, named Lafora bodies (LBs), which are considered neurotoxic and causative of the disease. The pathogenesis of LD is therefore centred on the question of how insoluble LBs emerge from soluble glycogen. Recent data clearly show that an abnormal glycogen chain length distribution, but neither hyperphosphorylation nor impairment of general autophagy, strictly correlates with glycogen accumulation and the presence of LBs. This review summarizes results obtained with patients, mouse models, and cell lines and consolidates apparent paradoxes in the LD literature. Based on the growing body of evidence, it proposes that LD is predominantly caused by an impairment in chain-length regulation affecting only a small proportion of the cellular glycogen. A better grasp of LD pathogenesis will further develop our understanding of glycogen metabolism and structure. It will also facilitate the development of clinical interventions that appropriately target the underlying cause of LD.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1080
KW - lafora disease
KW - laforin
KW - malin
KW - polyglucosan body
KW - chain length distribution
KW - glycogen phosphorylation
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474622
SN - 1866-8372
IS - 1080
ER -
TY - GEN
A1 - Geißler, Katja
A1 - Heblack, Jessica
A1 - Uugulu, Shoopala
A1 - Wanke, Heike
A1 - Blaum, Niels
T1 - Partitioning of Water Between Differently Sized Shrubs and Potential Groundwater Recharge in a Semiarid Savanna in Namibia
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - Introduction: Many semiarid regions around the world are presently experiencing significant changes in both climatic conditions and vegetation. This includes a disturbed coexistence between grasses and bushes also known as bush encroachment, and altered precipitation patterns with larger rain events. Fewer, more intense precipitation events might promote groundwater recharge, but depending on the structure of the vegetation also encourage further woody encroachment.
Materials and Methods: In this study, we investigated how patterns and sources of water uptake of Acacia mellifera (blackthorn), an important encroaching woody plant in southern African savannas, are associated with the intensity of rain events and the size of individual shrubs. The study was conducted at a commercial cattle farm in the semiarid Kalahari in Namibia (MAP 250 mm/a). We used soil moisture dynamics in different depths and natural stable isotopes as markers of water sources. Xylem water of fifteen differently sized individuals during eight rain events was extracted using a Scholander pressure bomb.
Results and Discussion: Results suggest the main rooting activity zone of A. mellifera in 50 and 75 cm soil depth but a reasonable water uptake from 10 and 25 cm. Any apparent uptake pattern seems to be driven by water availability, not time in the season. Bushes prefer the deeper soil layers after heavier rain events, indicating some evidence for the classical Walter’s two-layer hypothesis. However, rain events up to a threshold of 6 mm/day cause shallower depths of use and suggest several phases of intense competition with perennial grasses. The temporal uptake pattern does not depend on shrub size, suggesting a fast upwards water flow inside. d2H and d18O values in xylem water indicate that larger shrubs rely less on upper and very deep soil water than smaller shrubs. It supports the hypothesis that in environments where soil moisture is highly variable in the upper soil layers, the early investment in a deep tap-root to exploit deeper, more reliable water sources could reduce the probability of mortality during the establishment phase. Nevertheless, independent of size and time in the season, bushes do not compete with potential groundwater recharge. In a savanna encroached by A. mellifera, groundwater will most likely be affected indirectly.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 798
KW - bush encroachment
KW - groundwater recharge
KW - rooting depth
KW - Savannas
KW - stable isotopes
KW - shrub size
KW - Acacia mellifera
KW - rain event depth
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441110
SN - 1866-8372
IS - 798
ER -
TY - GEN
A1 - Mitic, Kristina
A1 - Grafe, Marianne
A1 - Batsios, Petros
A1 - Meyer, Irene
T1 - Partial Disassembly of the Nuclear Pore Complex Proteins during Semi-Closed Mitosis in Dictyostelium discoideum
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Dictyostelium cells undergo a semi-closed mitosis, during which the nuclear envelope (NE) persists; however, free diffusion between the cytoplasm and the nucleus takes place. To permit the formation of the mitotic spindle, the nuclear envelope must be permeabilized in order to allow diffusion of tubulin dimers and spindle assembly factors into the nucleus. In Aspergillus, free diffusion of proteins between the cytoplasm and the nucleus is achieved by a partial disassembly of the nuclear pore complexes (NPCs) prior to spindle assembly. In order to determine whether this is also the case in Dictyostelium, we analysed components of the NPC by immunofluorescence microscopy and live cell imaging and studied their behaviour during interphase and mitosis. We observed that the NPCs are absent from the contact area of the nucleoli and that some nucleoporins also localize to the centrosome and the spindle poles. In addition, we could show that, during mitosis, the central FG protein NUP62, two inner ring components and Gle1 depart from the NPCs, while all other tested NUPs remained at the NE. This leads to the conclusion that indeed a partial disassembly of the NPCs takes place, which contributes to permeabilisation of the NE during semi-closed mitosis.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1233
KW - nuclear pore complex
KW - nucleoporins
KW - semi-closed mitosis
KW - centrosome
KW - Dictyostelium
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-545341
SN - 1866-8372
IS - 3
ER -