TY  - JOUR
A1  - Wendt, Martin
A1  - Senftleben, Nele
A1  - Gros, Patrick
A1  - Schmitt, Thomas
T1  - Coping with environmental extremes
BT  - population ecology and behavioural adaptation of Erebia pronoe, an Alpine butterfly species
JF  - Insects : open access journal
N2  - Simple Summary:& nbsp;High alpine meadows are home to numerous endemic butterfly species. A combination of climate change and changes in agricultural practices has led to a severe decline in many species. A seemingly unaffected representative of this habitat is Erebia pronoe. We studied the behaviour, resource use and population structure of this species to explain its resilience and estimate its future survival potential. This species shows pronounced protandry in combination with serial eclosion. Males were significantly more active and mobile and were also caught significantly more often than females, resulting in a pronounced shift in sex ratio in the predicted population structure. The adults use a wide range of nectar plants and establish homeranges in areas of high habitat quality. Thus, Erebia pronoe adults use a wide array of resources combined with a slight specialisation to avoid niche overlap with closely related species. The resulting ecological flexibility seems to be an adaptation to unpredictable environmental conditions, which should be the result of a long-lasting adaptation process. Moreover, the combination of opportunism and modest specialisation should also be a good basis for coping with future changes caused by climate and land-use change.</p> <br /> <br></p> <br /> A mark-recapture study of the nominotypical Erebia pronoe in the Alps was conducted to survey its ecological demands and characteristics. Population structure analysis revealed a combination of protandry (one-week earlier eclosion of males) and serial eclosion. Significant differences between both sexes were found in population density (males: 580/ha & PLUSMN; 37 SE; females: 241/ha & PLUSMN; 66 SE), sex-ratio (2.4) and behaviour (57.7 vs. 11.9% flying). Both sexes used a wide range of nectar plants (Asteraceae, 77.3%; Dipsacaceae, 12.3%; Gentianaceae, 9.7%). The use of nectar plants shows a non-specific spectrum, which, however, completely avoids overlap with the locally co-occurring species Erebia nivalis. Movement patterns show the establishment of homeranges, which significantly limits the migration potential. Due to its broad ecological niche, E. pronoe will probably be able to react plastically to the consequences of climate change. The formation of high population densities, the unconcerned endangerment status, the unspecific resource spectrum and the sedentary character of the species make E. pronoe a potential indicator of the quality and general resource occurrence of alpine rupicolous grasslands.
KW  - mark-release-recapture
KW  - movement patterns
KW  - opportunistic behaviour
KW  - partial protandry
KW  - population demography
Y1  - 2021
U6  - https://doi.org/10.3390/insects12100896
SN  - 2075-4450
VL  - 12
IS  - 10
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Werchmeister, Rebecka Maria Larsen
A1  - Tang, Jing
A1  - Xiao, Xinxin
A1  - Wollenberger, Ulla
A1  - Hjuler, Hans Aage
A1  - Ulstrup, Jens
A1  - Zhang, Jingdong
T1  - Three-Dimensional Bioelectrodes Utilizing Graphene Based Bioink
JF  - Journal of The Electrochemical Society
N2  - Enzyme immobilization using nanomaterials offers new approaches to enhanced bioelectrochemical performance and is essential for the preparation of bioelectrodes with high reproducibility and low cost. In this report, we describe the development of new three-dimensional (3D) bioelectrodes by immobilizing a "bioink" of glucose oxidase (GOD) in a matrix of reduced graphene oxides (RGOs), polyethylenimine (PEI), and ferrocene carboxylic acid (FcCOOH) on carbon paper (CP). CP with 3D interwoven carbon fibers serves as a solid porous and electronically conducting skeleton, providing large surface areas and space for loading the bioink and diffusion of substrate molecules, respectively. RGO enhances contact between the GOD-matrix and CP, maintaining high conductivity. The composition of the bioink has been systematically optimized. The GOD bioelectrodes show linearly increasing electrocatalytic oxidation current toward glucose concentration up to 48 mM. A hybrid enzymatic biofuel cell equipped with the GOD bioelectrode as a bioanode and a platinum cathode furthermore registers a maximum power density of 5.1 mu W cm(-2) and an open circuit voltage of 0.40 V at 25 degrees C. The new method reported of preparing a bioelectrode by drop-casting the bioink onto the substrate electrode is facile and versatile, with the potential of application also for other enzymatic bioelectrodes.
Y1  - 2019
U6  - https://doi.org/10.1149/2.0261916jes
SN  - 0013-4651
SN  - 1945-7111
VL  - 166
IS  - 16
SP  - G170
EP  - G177
PB  - The Electrochemical Society
CY  - Pennington
ER  - 
TY  - JOUR
A1  - Werger, Luise
A1  - Bergmann, Joana
A1  - Weber, Ewald
A1  - Heinze, Johannes
T1  - Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects
JF  - Annals of Botany Plants
N2  - Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant–soil feedbacks—PSFs). However, information on wind effects on fine root morphology is scarce and the extent to which wind changes plant–soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant–soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant–soil interactions under changing environmental conditions.
KW  - Wind
KW  - root traits
KW  - root morphology
KW  - specific root length
KW  - plant–soil feedback
Y1  - 2020
U6  - https://doi.org/10.1093/aobpla/plaa050
SN  - 2041-2851
VL  - 12
IS  - 5
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Werner, Deljana
A1  - Behrsing, Olaf
A1  - Scharte, Gudrun
A1  - Woller, Jochen
A1  - Steup, Martin
A1  - Micheel, Burkhard
T1  - Monoclonal anti-diuron antibodies prevent inhibition of photosynthesis by diuron
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Wernet, Philippe
A1  - Kunnus, Kristjan
A1  - Schreck, Simon
A1  - Quevedo, Wilson
A1  - Kurian, Reshmi
A1  - Techert, Simone
A1  - de Groot, Frank M. F.
A1  - Odelius, Michael
A1  - Föhlisch, Alexander
T1  - Dissecting local atomic and intermolecular interactions of transition-metal ions in solution with selective X-ray spectroscopy
JF  - The journal of physical chemistry letters
N2  - Determining covalent and charge-transfer contributions to bonding in solution has remained an experimental challenge. Here, the quenching of fluorescence decay channels as expressed in dips in the L-edge X-ray spectra of solvated 3d transition-metal ions and complexes was reported as a probe. With a full set of experimental and theoretical ab initio L-edge X-ray spectra of aqueous Cr3+, including resonant inelastic X-ray scattering, we address covalency and charge transfer for this prototypical transition-metal ion in solution. We dissect local atomic effects from intermolecular interactions and quantify X-ray optical effects. We find no evidence for the asserted ultrafast charge transfer to the solvent and show that the dips are readily explained by X-ray optical effects and local atomic state dependence of the fluorescence yield. Instead, we find, besides ionic interactions, a covalent contribution to the bonding in the aqueous complex of ligand-to-metal charge-transfer character.
Y1  - 2012
U6  - https://doi.org/10.1021/jz301486u
SN  - 1948-7185
VL  - 3
IS  - 23
SP  - 3448
EP  - 3453
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Westbury, Michael V.
A1  - Baleka, Sina Isabelle
A1  - Barlow, Axel
A1  - Hartmann, Stefanie
A1  - Paijmans, Johanna L. A.
A1  - Kramarz, Alejandro
A1  - Forasiepi, Analia M.
A1  - Bond, Mariano
A1  - Gelfo, Javier N.
A1  - Reguero, Marcelo A.
A1  - Lopez-Mendoza, Patricio
A1  - Taglioretti, Matias
A1  - Scaglia, Fernando
A1  - Rinderknecht, Andres
A1  - Jones, Washington
A1  - Mena, Francisco
A1  - Billet, Guillaume
A1  - de Muizon, Christian
A1  - Luis Aguilar, Jose
A1  - MacPhee, Ross D. E.
A1  - Hofreiter, Michael
T1  - A mitogenomic timetree for Darwin’s enigmatic South American mammal  Macrauchenia patachonica
JF  - Nature Communications
N2  - The unusual mix of morphological traits displayed by extinct South American native ungulates (SANUs) confounded both Charles Darwin, who first discovered them, and Richard Owen, who tried to resolve their relationships. Here we report an almost complete mitochondrial genome for the litoptern Macrauchenia. Our dated phylogenetic tree places Macrauchenia as sister to Perissodactyla, but close to the radiation of major lineages within Laurasiatheria. This position is consistent with a divergence estimate of B66Ma (95% credibility interval, 56.64-77.83 Ma) obtained for the split between Macrauchenia and other Panperissodactyla. Combined with their morphological distinctiveness, this evidence supports the positioning of Litopterna (possibly in company with other SANU groups) as a separate order within Laurasiatheria. We also show that, when using strict criteria, extinct taxa marked by deep divergence times and a lack of close living relatives may still be amenable to palaeogenomic analysis through iterative mapping against more distant relatives.
Y1  - 2017
U6  - https://doi.org/10.1038/ncomms15951
SN  - 2041-1723
VL  - 8
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Westbury, Michael V.
A1  - Dalerumb, Fredrik
A1  - Noren, Karin
A1  - Hofreiter, Michael
T1  - Complete mitochondrial genome of a bat-eared fox (Otocyon megalotis), along with phylogenetic considerations
JF  - Mitochondrial DNA. Part B
N2  - The bat-eared fox, Otocyon megalotis, is the only member of its genus and is thought to occupy a basal position within the dog family. These factors can lead to challenges in complete mitochondrial reconstructions and accurate phylogenetic positioning. Here, we present the first complete mitochondrial genome of the bat-eared fox recovered using shotgun sequencing and iterative mapping to three distantly related species. Phylogenetic analyses placed the bat-eared fox basal in the Canidae family within the clade including true foxes (Vulpes) and the raccoon dog (Nyctereutes) with high support values. This position is in good agreement with previously published results based on short fragments of mitochondrial and nuclear genes, therefore adding more support to the basal positioning of the bat-eared fox within Canidae.
KW  - Phylogenetics
KW  - mitochondria
KW  - iterative mapping
KW  - Canidae
Y1  - 2017
U6  - https://doi.org/10.1080/23802359.2017.1331325
SN  - 2380-2359
VL  - 2
IS  - 1
SP  - 298
EP  - 299
PB  - Routledge, Taylor & Francis Group
CY  - London
ER  - 
TY  - JOUR
A1  - Westbury, Michael V.
A1  - Hartmann, Stefanie
A1  - Barlow, Axel
A1  - Wiesel, Ingrid
A1  - Leo, Viyanna
A1  - Welch, Rebecca
A1  - Parker, Daniel M.
A1  - Sicks, Florian
A1  - Ludwig, Arne
A1  - Dalen, Love
A1  - Hofreiter, Michael
T1  - Extended and continuous decline in effective population size results in low genomic diversity in the world's rarest hyena species, the brown hyena
JF  - Molecular biology and evolution
N2  - Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of <10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low-coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa. We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started similar to 1 Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.
KW  - evolution
KW  - hyena
KW  - genomics
KW  - population genomics
KW  - diversity
Y1  - 2018
U6  - https://doi.org/10.1093/molbev/msy037
SN  - 0737-4038
SN  - 1537-1719
VL  - 35
IS  - 5
SP  - 1225
EP  - 1237
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Westbury, Michael V.
A1  - Prost, Stefan
A1  - Seelenfreund, Andrea
A1  - Ramirez, Jose-Miguel
A1  - Matisoo-Smith, Elizabeth A.
A1  - Knapp, Michael
T1  - First complete mitochondrial genome data from ancient South American camelids - The mystery of the chilihueques from Isla Mocha (Chile)
JF  - Scientific reports
Y1  - 2016
U6  - https://doi.org/10.1038/srep38708
SN  - 2045-2322
VL  - 6
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Wettstein, Christoph
A1  - Kano, Kenji
A1  - Schaefer, Daniel
A1  - Wollenberger, Ursula
A1  - Lisdat, Fred
T1  - Interaction of Flavin-Dependent Fructose Dehydrogenase with Cytochrome c as Basis for the Construction of Biomacromolecular Architectures on Electrodes
JF  - Analytical chemistry
N2  - The creation of electron transfer (ET) chains based on the defined arrangement of enzymes and redox proteins on electrode surfaces represents an interesting approach within the field of bioelectrocatalysis. In this study, we investigated the ET reaction of the flavin-dependent enzyme fructose dehydrogenase (FDH) with the redox protein cytochrome c (cyt c). Two different pH optima were found for the reaction in acidic and neutral solutions. When cyt c was adsorbed on an electrode surface while the enzyme remained in solution, ET proceeded efficiently in media of neutral pH. Interprotein ET was also observed in acidic media; however, it appeared to be less efficient. These findings suggest that two different ET pathways between the enzyme and cyt c may occur. Moreover, cyt c and FDH were immobilized in multiple layers on an electrode surface by means of another biomacromolecule: DNA (double stranded) using the layer -by -layer technique. The biprotein multilayer architecture showed a catalytic response in dependence on the fructose concentration, indicating that the ET reaction between both proteins is feasible even in the immobilized state. The electrode showed a defined response to fructose and a good storage stability. Our results contribute to the better understanding of the ET reaction between FDH and cyt c and provide the basis for the creation of all-biomolecule based fructose sensors the sensitivity of which can be controlled by the layer preparation.
Y1  - 2016
U6  - https://doi.org/10.1021/acs.analchem.6b00815
SN  - 0003-2700
SN  - 1520-6882
VL  - 88
SP  - 6382
EP  - 6389
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wetzel, Alexandra Nicole
A1  - Scholtka, Bettina
A1  - Gerecke, Christian
A1  - Kleuser, Burkhard
T1  - Epigenetic histone modulation contributes to improvements in inflammatory bowel disease via EBI3
JF  - Cellular and molecular life sciences
N2  - Ulcerative colitis (UC) is characterized by relapsing-remitting inflammatory episodes paralleled by varying cytokine levels, suggesting that switching epigenetic processes might be involved. However, the epigenetic impact on cytokine levels in colitis is mostly unexplored. The heterodimeric interleukin (IL)-12 cytokine family have various functions in both pro- and anti-inflammatory processes. The family member IL-35 (EBI3/IL-12p35) was recently reported to play an anti-inflammatory role in UC. Therefore, we aimed to investigate a possible epigenetic regulation of the IL-35 subunits in vitro and in vivo, and to examine the epigenetic targeting of EBI3 expression as a therapeutic option for UC. Exposure to either the pro-inflammatory TNF alpha or to histone deacetylase inhibitors (HDACi) significantly increased EBI3 expression in Human Colon Epithelial Cells (HCEC) generated from healthy tissue. When applied in combination, a drastic upregulation of EBI3 expression occurred, suggesting a synergistic mechanism. Consequently, IL-35 was increased as well. In vivo, the intestines of HDACi-treated wild-type mice exhibited reduced pathological signs of colitis compared to non-treated colitic mice. However, the improvement by HDACi treatment was completely lost in Ebi3-deficient mice (Ebi3(-/-)). In fact, HDACi appeared to exacerbate the disease phenotype in Ebi3(-/-). In conclusion, our results reveal that under inflammatory conditions, EBI3 is upregulated by the epigenetic mechanism of histone acetylation. The in vivo data show that the deficiency of EBI3 plays a key role in colitis manifestation. Concordantly, our data suggest that conditions promoting histone acetylation, such as upon HDACi application, improve colitis by a mechanism involving the local formation of the anti-inflammatory cytokine IL-35.
KW  - Histone deacetylase inhibitor
KW  - Inhibitory cytokines
KW  - Interleukin-35
KW  - SAHA
KW  - Ulcerative colitis
Y1  - 2020
U6  - https://doi.org/10.1007/s00018-020-03451-9
SN  - 1420-682X
SN  - 1420-9071
VL  - 77
IS  - 23
SP  - 5017
EP  - 5030
PB  - Springer International Publishing AG
CY  - Cham (ZG)
ER  - 
TY  - JOUR
A1  - Weyhenmeyer, G. A.
A1  - Adrian, Rita
A1  - Gaedke, Ursula
A1  - Livingstone, D. M.
A1  - Maberly, Stephen C.
T1  - Response of phytoplankton in European lakes to a change in the North Atlantic Oscillation
Y1  - 2002
SN  - 0368-0770
ER  - 
TY  - JOUR
A1  - Weyhenmeyer, Gesa A.
A1  - Mackay, Murray
A1  - Stockwell, Jason D.
A1  - Thiery, Wim
A1  - Grossart, Hans-Peter
A1  - Augusto-Silva, Petala B.
A1  - Baulch, Helen M.
A1  - de Eyto, Elvira
A1  - Hejzlar, Josef
A1  - Kangur, Kuelli
A1  - Kirillin, Georgiy
A1  - Pierson, Don C.
A1  - Rusak, James A.
A1  - Sadro, Steven
A1  - Woolway, R. Iestyn
T1  - Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming
JF  - Scientific reports
N2  - Citizen science projects have a long history in ecological studies. The research usefulness of such projects is dependent on applying simple and standardized methods. Here, we conducted a citizen science project that involved more than 3500 Swedish high school students to examine the temperature difference between surface water and the overlying air (T-w-T-a) as a proxy for sensible heat flux (Q(H)). If Q(H) is directed upward, corresponding to positive T-w-T-a, it can enhance CO2 and CH4 emissions from inland waters, thereby contributing to increased greenhouse gas concentrations in the atmosphere. The students found mostly negative T-w-T-a across small ponds, lakes, streams/rivers and the sea shore (i.e. downward Q(H)), with T-w-T-a becoming increasingly negative with increasing T-a. Further examination of T-w-T-a using high-frequency temperature data from inland waters across the globe confirmed that T-w-T-a is linearly related to T-a. Using the longest available high-frequency temperature time series from Lake Erken, Sweden, we found a rapid increase in the occasions of negative T-w-T-a with increasing annual mean T-a since 1989. From these results, we can expect that ongoing and projected global warming will result in increasingly negative T-w-T-a, thereby reducing CO2 and CH4 transfer velocities from inland waters into the atmosphere.
Y1  - 2017
U6  - https://doi.org/10.1038/srep43890
SN  - 2045-2322
VL  - 7
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Benz, Stephanie
A1  - Karl, Stephan
A1  - Jeschek, Marie
A1  - Jewgenow, Katarina
A1  - Fickel, Jörns
T1  - Paternal heat exposure causes DNA methylation and gene expression changes of Stat3 in Wild guinea pig sons
JF  - Ecology and evolution
N2  - Epigenetic mechanisms convey environmental information through generations and can regulate gene expression. Epigenetic studies in wild mammals are rare, but enable understanding adaptation processes as they may occur in nature. In most wild mammal species, males are the dispersing sex and thus often have to cope with differing habitats and thermal changes more rapidly than the often philopatric females. As temperature is a major environmental selection factor, we investigated whether genetically heterogeneous Wild guinea pig (Cavia aperea) males adapt epigenetically to an increase in temperature, whether that response will be transmitted to the next generation(s), and whether it regulates mRNA expression. Five (F0) adult male guinea pigs were exposed to an increased ambient temperature for 2 months, corresponding to the duration of the species' spermatogenesis. To study the effect of heat, we focused on the main thermoregulatory organ, the liver. We analyzed CpG-methylation changes of male offspring (F1) sired before and after the fathers' heat treatment (as has recently been described in Weyrich et al. [Mol. Ecol., 2015]). Transcription analysis was performed for the three genes with the highest number of differentially methylated changes detected: the thermoregulation gene Signal Transducer and Activator of Transcription 3 (Stat3), the proteolytic peptidase gene Cathepsin Z (Ctsz), and Sirtuin 6 (Sirt6) with function in epigenetic regulation. Stat3 gene expression was significantly reduced (P < 0.05), which indicated a close link between CpG-methylation and expression levels for this gene. The two other genes did not show gene expression changes. Our results indicate the presence of a paternal transgenerational epigenetic effect. Quick adaptation to climatic changes may become increasingly relevant for the survival of wildlife species as global temperatures are rising.
KW  - Adaptation
KW  - DNA methylation
KW  - nonmodel species
KW  - Paternal effects
KW  - thermoregulation
KW  - transgenerational epigenetic inheritance
Y1  - 2016
U6  - https://doi.org/10.1002/ece3.1993
SN  - 2045-7758
VL  - 6
SP  - 2657
EP  - 2666
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Guerrero-Altamirano, Tania P.
A1  - Yasar, Selma
A1  - Czirjak, Gábor-Árpád
A1  - Wachter, Bettina
A1  - Fickel, Jörns
T1  - First Steps towards the development of epigenetic biomarkers in female cheetahs (Acinonyx jubatus)
JF  - Life : open access journal
N2  - Free-ranging cheetahs (Acinonyx jubatus) are generally healthy, whereas cheetahs under human care, such as those in zoological gardens, suffer from ill-defined infectious and degenerative pathologies. These differences are only partially explained by husbandry management programs because both groups share low genetic diversity. However, mounting evidence suggests that physiological differences between populations in different environments can be tracked down to differences in epigenetic signatures. Here, we identified differentially methylated regions (DMRs) between free-ranging cheetahs and conspecifics in zoological gardens and prospect putative links to pathways relevant to immunity, energy balance and homeostasis. Comparing epigenomic DNA methylation profiles obtained from peripheral blood mononuclear cells (PBMCs) from eight free-ranging female cheetahs from Namibia and seven female cheetahs living in zoological gardens within Europe, we identified DMRs of which 22 were hypermethylated and 23 hypomethylated. Hypermethylated regions in cheetahs under human care were located in the promoter region of a gene involved in host-pathogen interactions (KLC1) and in an intron of a transcription factor relevant for the development of pancreatic beta-cells, liver, and kidney (GLIS3). The most canonical mechanism of DNA methylation in promoter regions is assumed to repress gene transcription. Taken together, this could indicate that hypermethylation at the promoter region of KLC1 is involved in the reduced immunity in cheetahs under human care. This approach can be generalized to characterize DNA methylation profiles in larger cheetah populations under human care with a more granular longitudinal data collection, which, in the future, could be used to monitor the early onset of pathologies, and ultimately translate into the development of biomarkers with prophylactic and/or therapeutic potential.
KW  - animals under human care
KW  - captivity
KW  - carnivore
KW  - DNA methylation;
KW  - felidae
KW  - free-ranging
KW  - wildlife
Y1  - 2022
U6  - https://doi.org/10.3390/life12060920
SN  - 2075-1729
VL  - 12
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Jeschek, Marie
A1  - Schrapers, Katharina T.
A1  - Lenz, Dorina
A1  - Chung, Tzu Hung
A1  - Ruebensam, Kathrin
A1  - Yasar, Sermin
A1  - Schneemann, Markus
A1  - Ortmann, Sylvia
A1  - Jewgenow, Katarina
A1  - Fickel, Jörns
T1  - Diet changes alter paternally inherited epigenetic pattern in male Wild guinea pigs
JF  - Environmental Epigenetics
N2  - Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impact on the offspring’s adaptability to changes in diet composition, we investigated if low protein diet (LPD) in F0 males caused epigenetic alterations in their subsequently sired sons. We therefore fed F0 male Wild guinea pigs with a diet lowered in protein content (LPD) and investigated DNA methylation in sons sired before and after their father’s LPD treatment in both, liver and testis tissues. Our results point to a ‘heritable epigenetic response’ of the sons to the fathers’ dietary change. Because we detected methylation changes also in the testis tissue, they are likely to be transmitted to the F2 generation. Gene-network analyses of differentially methylated genes in liver identified main metabolic pathways indicating a metabolic reprogramming (‘metabolic shift’). Epigenetic mechanisms, allowing an immediate and inherited adaptation may thus be important for the survival of species in the context of a persistently changing environment, such as climate change.
KW  - DNA methylation
KW  - exposure
KW  - wild mammal species
KW  - inheritance
KW  - plasticity
KW  - adaptation
Y1  - 2018
U6  - https://doi.org/10.1093/eep/dvy011
SN  - 2058-5888
VL  - 4
IS  - 2
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Lenz, Dorina
A1  - Fickel, Jörns
T1  - Environmental Change-Dependent Inherited Epigenetic Response
JF  - GENES
N2  - Epigenetic modifications are a mechanism conveying environmental information to subsequent generations via parental germ lines. Research on epigenetic responses to environmental changes in wild mammals has been widely neglected, as well as studies that compare responses to changes in different environmental factors. Here, we focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to either diet (~40% less protein) or temperature increase (10 °C increased temperature). Because both experiments focused on the liver as the main metabolic and thermoregulation organ, we were able to decipher if epigenetic changes differed in response to different environmental changes. Reduced representation bisulfite sequencing (RRBS) revealed differentially methylated regions (DMRs) in annotated genomic regions in sons sired before (control) and after the fathers’ treatments. We detected both a highly specific epigenetic response dependent on the environmental factor that had changed that was reflected in genes involved in specific metabolic pathways, and a more general response to changes in outer stimuli reflected by epigenetic modifications in a small subset of genes shared between both responses. Our results indicated that fathers prepared their offspring for specific environmental changes by paternally inherited epigenetic modifications, suggesting a strong paternal contribution to adaptive processes.
KW  - DNA methylation
KW  - exposure
KW  - wild mammal species
KW  - inheritance
KW  - plasticity
KW  - adaptation
KW  - RRBS
Y1  - 2018
U6  - https://doi.org/10.3390/genes10010004
SN  - 2073-4425
VL  - 10
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Lenz, Dorina
A1  - Jeschek, Marie
A1  - Tzu Hung Chung, 
A1  - Ruebensam, Kathrin
A1  - Goeritz, Frank
A1  - Jewgenow, Katarina
A1  - Fickel, Jörns
T1  - Paternal intergenerational epigenetic response to heat exposure in male Wild guinea pigs
JF  - Molecular ecology
N2  - Epigenetic modifications, of which DNA methylation is the best studied one, can convey environmental information through generations via parental germ lines. Past studies have focused on the maternal transmission of epigenetic information to the offspring of isogenic mice and rats in response to external changes, whereas heterogeneous wild mammals as well as paternal epigenetic effects have been widely neglected. In most wild mammal species, males are the dispersing sex and have to cope with differing habitats and thermal changes. As temperature is a major environmental factor we investigated if genetically heterogeneous Wild guinea pig (Cavia aperea) males can adapt epigenetically to an increase in temperature and if that response will be transmitted to the next generation(s). Five adult male guinea pigs (F0) were exposed to an increased ambient temperature for 2 months, i.e. the duration of spermatogenesis. We studied the liver (as the main thermoregulatory organ) of F0 fathers and F1 sons, and testes of F1 sons for paternal transmission of epigenetic modifications across generation(s). Reduced representation bisulphite sequencing revealed shared differentially methylated regions in annotated areas between F0 livers before and after heat treatment, and their sons’ livers and testes, which indicated a general response with ecological relevance. Thus, paternal exposure to a temporally limited increased ambient temperature led to an ‘immediate’ and ‘heritable’ epigenetic response that may even be transmitted to the F2 generation. In the context of globally rising temperatures epigenetic mechanisms may become increasingly relevant for the survival of species.
KW  - adaptation
KW  - Cavia aperea
KW  - DNA methylation
KW  - environmental factor
KW  - global change
KW  - plasticity
KW  - temperature increase
Y1  - 2016
U6  - https://doi.org/10.1111/mec.13494
SN  - 0962-1083
SN  - 1365-294X
VL  - 25
SP  - 1729
EP  - 1740
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Weyrich, Alexandra
A1  - Yasar, Selma
A1  - Lenz, Dorina
A1  - Fickel, Jörns
T1  - Tissue-specific epigenetic inheritance after paternal heat exposure in male wild guinea pigs
JF  - Mammalian genome
N2  - External temperature change has been shown to modify epigenetic patterns, such as DNA methylation, which regulates gene expression. DNA methylation is heritable, and as such provides a mechanism to convey environmental information to subsequent generations. Studies on epigenetic response to temperature increase are still scarce in wild mammals, even more so studies that compare tissue-specific epigenetic responses. Here, we aim to address differential epigenetic responses on a gene and gene pathway level in two organs, liver and testis. We chose these organs, because the liver is the main metabolic and thermoregulation organ, and epigenetic modifications in testis are potentially transmitted to the F2 generation. We focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to an ambient temperature increase of 10 degrees C, and investigated differential methylated regions of sons sired before and after the paternal exposure using Reduced Representation Bisulfite Sequencing. We detected both a highly tissue-specific epigenetic response, reflected in genes involved in organ-specific metabolic pathways, and a more general regulation of single genes epigenetically modified in both organs. We conclude that genomes are context-specifically differentially epigenetically regulated in response to temperature increase. These findings emphasize the epigenetic relevance in cell differentiation, which is essential for the specific function(s) of complex organs, and is represented in a diverse molecular regulation of genes and gene pathways. The results also emphasize the paternal contribution to adaptive processes.
KW  - DNA methylation
KW  - gene-expression
KW  - CPG Islands
KW  - stress
KW  - hyperthermia
KW  - testis
Y1  - 2020
U6  - https://doi.org/10.1007/s00335-020-09832-6
SN  - 0938-8990
SN  - 1432-1777
VL  - 31
IS  - 5-6
SP  - 157
EP  - 169
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Whitcomb, Sarah J.
A1  - Nguyen, Huu Cuong
A1  - Brückner, Franziska
A1  - Hesse, Holger
A1  - Hoefgen, Rainer
T1  - CYSTATHIONINE GAMMA-SYNTHASE activity in rice is developmentally regulated and strongly correlated with sulfate
JF  - Plant science : an international journal of experimental plant biology
N2  - An important goal of rice cultivar development is improvement of protein quality, especially with respect to essential amino acids such as methionine. With the goal of increasing seed methionine content, we generated Oryza sativa ssp. japonica cv. Taipei 309 transgenic lines expressing a feedback-desensitized CYSTATHIONINE GAMMA-SYNTHASE from Arabidopsis thaliana (AtD-CGS) under the control of the maize ubiquitin promoter. Despite persistently elevated cystathionine gamma-synthase (CGS) activity in the AtD-CGS transgenic lines relative to untransformed Taipei, sulfate was the only sulfur-containing compound found to be elevated throughout vegetative development. Accumulation of methionine and other sulfur-containing metabolites was limited to the leaves of young plants. Sulfate concentration was found to strongly and positively correlate with CGS activity across vegetative development, irrespective of whether the activity was provided by the endogenous rice CGS or by a combination of endogenous and AtD-CGS. Conversely, the concentrations of glutathione, valine, and leucine were clearly negatively correlated with CGS activity in the same tissues. We also observed a strong decrease in CGS activity in both untransformed Taipei and the AtD-CGS transgenic lines as the plants approached heading stage. The mechanism for this downregulation is currently unknown and of potential importance for efforts to increase methionine content in rice.
KW  - Aromatic amino acids
KW  - AtD-CGS
KW  - Branched chain amino acids
KW  - CYSTATHIONINE GAMMA-SYNTHASE
KW  - Glutathione
KW  - Oryza sativa ssp japonica cv. taipei 309
KW  - Sulfate
Y1  - 2018
U6  - https://doi.org/10.1016/j.plantsci.2018.02.016
SN  - 0168-9452
VL  - 270
SP  - 234
EP  - 244
PB  - Elsevier
CY  - Clare
ER  - 
TY  - JOUR
A1  - Whiteley, Liam
A1  - Haug, Maria
A1  - Klein, Kristina
A1  - Willmann, Matthias
A1  - Bohn, Erwin
A1  - Chiantia, Salvatore
A1  - Schwarz, Sandra
T1  - Cholesterol and host cell surface proteins contribute to cell-cell fusion induced by the Burkholderia type VI secretion system 5
JF  - PLoS one
N2  - Following escape into the cytoplasm of host cells, Burkholderia pseudomallei and the related species Burkholderia thailandensis employ the type VI secretion system 5 ( T6SS-5) to induce plasma membrane fusion with an adjacent host cell. This process leads to the formation of multinucleated giant cells and facilitates bacterial access to an uninfected host cell in a direct manner. Despite its importance in virulence, the mechanism of the T6SS-5 and the role of host cell factors in cell-cell fusion remain elusive. To date, the T6SS-5 is the only system of bacterial origin known to induce host-cell fusion. To gain insight into the nature of T6SS-5-stimulated membrane fusion, we investigated the contribution of cholesterol and proteins exposed on the host cell surface, which were shown to be critically involved in virus-mediated giant cell formation. In particular, we analyzed the effect of host cell surface protein and cholesterol depletion on the formation of multinucleated giant cells induced by B. thailandensis. Acute protease treatment of RAW264.7 macrophages during infection with B. thailandensis followed by agarose overlay assays revealed a strong reduction in the number of cell-cell fusions compared with EDTA treated cells. Similarly, proteolytic treatment of specifically infected donor cells or uninfected recipient cells significantly decreased multinucleated giant cell formation. Furthermore, modulating host cell cholesterol content by acute cholesterol depletion from cellular membranes by methyl-beta-cyclodextrin treatment or exogenous addition of cholesterol impaired the ability of B. thailandensis to induce cell-cell fusions. The requirement of physiological cholesterol levels suggests that the membrane organization or mechanical properties of the lipid bilayer influence the fusion process. Altogether, our data suggest that membrane fusion induced by B. pseudomallei and B. thailandensis involves a complex interplay between the T6SS-5 and the host cell.
Y1  - 2017
U6  - https://doi.org/10.1371/journal.pone.0185715
SN  - 1932-6203
VL  - 12
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Wicaksono, Wisnu Adi
A1  - Braun, Maria
A1  - Bernhardt, Jörg
A1  - Riedel, Katharina
A1  - Cernava, Tomislav
A1  - Berg, Gabriele
T1  - Trade-off for survival
BT  - microbiome response to chemical exposure combines activation of intrinsic resistances and adapted metabolic activity
JF  - Environment international : a journal of science, technology, health, monitoring and policy
N2  - The environmental micmbiota is increasingly exposed to chemical pollution. While the emergence of multi-resistant pathogens is recognized as a global challenge, our understanding of antimicrobial resistance (AMR) development from native microbiomes and the risks associated with chemical exposure is limited. By implementing a lichen as a bioindicator organism and model for a native microbiome, we systematically examined responses towards antimicrobials (colistin, tetracycline, glyphosate, and alkylpyrazine). Despite an unexpectedly high resilience, we identified potential evolutionary consequences of chemical exposure in terms of composition and functioning of native bacterial communities. Major shifts in bacterial composition were observed due to replacement of naturally abundant taxa; e.g. Chthoniobacterales by Pseudomonadales. A general response, which comprised activation of intrinsic resistance and parallel reduction of metabolic activity at RNA and protein levels was deciphered by a multi-omics approach. Targeted analyses of key taxa based on metagenome-assembled genomes reflected these responses but also revealed diversified strategies of their players. Chemical-specific responses were also observed, e.g., glyphosate enriched bacterial r-strategists and activated distinct ARGs. Our work demonstrates that the high resilience of the native micmbiota toward antimicrobial exposure is not only explained by the presence of antibiotic resistance genes but also adapted metabolic activity as a trade-off for survival. Moreover, our results highlight the importance of native microbiomes as important but so far neglected AMR reservoirs. We expect that this phenomenon is representative for a wide range of environmental microbiota exposed to chemicals that potentially contribute to the emergence of antibiotic-resistant bacteria from natural environments.
Y1  - 2022
U6  - https://doi.org/10.1016/j.envint.2022.107474
SN  - 1873-6750
VL  - 168
PB  - Elsevier Science
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
T1  - Survival in changing environments : modeling the impact of climate change and land use on raptors in arid savanna
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Dean, W. R. J.
A1  - Jeltsch, Florian
T1  - Predicting the breeding success of large raptors in arid southern Africa : a first assessment
N2  - Raptors are often priorities for conservation efforts and breeding success is a target measure for assessing their conservation status. The breeding success of large raptors in and southern Africa is thought to be higher in years of high rainfall. While this correlation has been found in several studies, it has not yet been shown for data from a wider geographical area. In conservation research, it is important to explore the differences between spatially- separated populations to estimate and to compare their conservation status, and to deduce specific management strategies. Using a theoretical approach, we develop a simplistic model to explain the breeding success-rainfall relationship in large African raptors at larger spatial scales. Secondly, we validate this model and we show that the inclusion of field data leads to consistent predictions. In particular, we recommend that the average size of the 'effective territory' should be included in the relationship between annual rainfall and breeding success of raptors in and southern Africa. Accordingly, we suggest that breeding success is a function of precipitation and inter- nest distance. We present a new measure of territory quality depending on rainfall and territory size. We suggest that our model provides a useful first approach to assess breeding success in large raptors of and southern Africa. However, we strongly emphasise the need to gather more data to further verify our model. A general problem in conservation research is to compare the status of populations assessed in different study areas under changing environmental conditions. Our simplistic approach indicates that this problem can be overcome by using a weighted evaluation of a target measure (i.e. breeding success), taking regional differences into account
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Groeneveld, Jürgen
A1  - Jeltsch, Florian
A1  - Grimm, Volker
T1  - Mitigation of climate change impacts on raptors by behavioural adaptation : ecological buffering mechanisms
N2  - The predicted climate change causes deep concerns on the effects of increasing temperatures and changing precipitation patterns on species viability and, in turn, on biodiversity. Models of Population Viability Analysis (PVA) provide a powerful tool to assess the risk of species extinction. However, most PVA models do not take into account the potential effects of behavioural adaptations. Organisms might adapt to new environmental situations and thereby mitigate negative effects of climate change. To demonstrate such mitigation effects, we use an existing PVA model describing a population of the tawny eagle (Aquila rapax) in the southern Kalahari. This model does not include behavioural adaptations. We develop a new model by assuming that the birds enlarge their average territory size to compensate for lower amounts of precipitation. Here, we found the predicted increase in risk of extinction due to climate change to be much lower than in the original model. However, this "buffering" of climate change by behavioural adaptation is not very effective in coping with increasing interannual variances. We refer to further examples of ecological "buffering mechanisms" from the literature and argue that possible buffering mechanisms should be given due consideration when the effects of climate change on biodiversity are to be predicted. (c) 2004 Elsevier B.V. All rights reserved
Y1  - 2005
SN  - 0921-8181
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Groeneveld, Jürgen
A1  - Jeltsch, Florian
A1  - Grimm, Volker
T1  - Mitigation of climate change impacts on raptors by behavioural adaption : ecological buffering mechanism
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Jeltsch, Florian
A1  - Dean, Richard
A1  - Moloney, Kirk A.
A1  - Wissel, Christian
T1  - Does climate change in arid savanna affect the population persistence of raptors?
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Jeltsch, Florian
A1  - Dean, Richard
A1  - Moloney, Kirk A.
A1  - Wissel, Christian
T1  - Weather does matter : simulating population dynamics of tawny eagle (Aquila rapax) under various rainfall scenarios
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Wieczorek, Mareike
A1  - Kruse, Stefan
A1  - Epp, Laura Saskia
A1  - Kolmogorov, Alexei
A1  - Nikolaev, Anatoly N.
A1  - Heinrich, Ingo
A1  - Jeltsch, Florian
A1  - Pestryakova, Luidmila Agafyevna
A1  - Zibulski, Romy
A1  - Herzschuh, Ulrike
T1  - Dissimilar responses of larch stands in northern Siberia to increasing temperatures-a field and simulation based study
JF  - Ecology : a publication of the Ecological Society of America
N2  - Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. In our study, which was conducted in the Taimyr Depression in the North Siberian Lowlands, w present a combined field-and model-based approach helping us to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that tree density is highest in the forest-tundra, and average tree size decreases from closed forest to single-tree tundra. Age-structure analyses indicate that the trees in the closed forest and forest-tundra have been present for at least similar to 240 yr. At all sites except the most southerly ones, past establishment is positively correlated with regional temperature increase. In the single-tree tundra, however, a change in growth form from krummholz to erect trees, beginning similar to 130 yr ago, rather than establishment date has been recorded. Seed mass decreases from south to north, while seed quantity increases. Simulations with LAVESI (Larix Vegetation Simulator) further suggest that relative density changes strongly in response to a warming signal in the forest-tundra while intra-specific competition limits densification in the closed forest and seed limitation hinders densification in the single-tree tundra. We find striking differences in strength and timing of responses to recent climate warming. While forest-tundra stands recently densified, recruitment is almost non-existent at the southern and northern end of the ecotone due to autecological processes. Palaeo-treelines may therefore be inappropriate to infer past temperature changes at a fine scale. Moreover, a lagged treeline response to past warming will, via feedback mechanisms, influence climate change in the future.
KW  - climate change
KW  - closed forest
KW  - dendroecology
KW  - forest change
KW  - latitude
KW  - recruitment
KW  - tundra
KW  - vegetation model
Y1  - 2017
U6  - https://doi.org/10.1002/ecy.1887
SN  - 0012-9658
SN  - 1939-9170
VL  - 98
SP  - 2343
EP  - 2355
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Jeltsch, Florian
A1  - Ward, D.
T1  - Minimum recruitment frequency in plants with episodic recruitment
N2  - There is concern about the lack of recruitment of Acacia trees in the Negev desert of Israel. We have developed three models to estimate the frequency of recruitment necessary for long-term population survival (i.e. positive average population growth for 1,000 years and <10% probability of extinction). Two models assume purely episodic recruitment based on the general notion that recruitment in and environments is highly episodic. They differ in that the deterministic model investigates average dynamics while the stochastic model does not. Studies indicating that recruitment episodes in and environments have been overemphasized motivated the development of the third model. This semi-stochastic model simulates a mixture of continuous and episodic recruitment. Model analysis was done analytically for the deterministic model and via running model simulations for the stochastic and semi-stochastic models. The deterministic and stochastic models predict that, on average, 2.2 and 3.7 recruitment events per century, respectively, are necessary to sustain the population. According to the semi-stochastic model, 1.6 large recruitment events per century and an annual probability of 50% that a small recruitment event occurs are needed. A consequence of purely episodic recruitment is that all recruitment episodes produce extremely large numbers of recruits (i.e. at odds with field observations), an evaluation that holds even when considering that rare events must be large. Thus, the semi- stochastic model appears to be the most realistic model. Comparing the prediction of the semi-stochastic model to field observations in the Negev desert shows that the absence of observations of extremely large recruitment events is no reason for concern. However, the almost complete absence of small recruitment events is a serious reason for concern. The lack of recruitment may be due to decreased densities of large mammalian herbivores and might be further exacerbated by possible changes in climate, both in terms of average precipitation and the temporal distribution of rain
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Jeltsch, Florian
A1  - Ward, D.
T1  - Do spatial effects play a role in the spatial distribution of desert dwelling Acacias?
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Schmidt, H.
A1  - Jeltsch, Florian
A1  - Ward, D.
T1  - Linking a spatially-explicit model of acacias to GIS and remotely-sensed data
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Ward, D.
A1  - Thulke, Hans-Hermann
A1  - Jeltsch, Florian
T1  - From snap-shot information to long-term population dynamics of Acacias by a simulation model
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, T.
A1  - Jeltsch, Florian
T1  - Long-term dynamics in arid and semi-arid ecosystems : synthesis of a workshop
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegmann, Alex
A1  - Rutschmann, Ronja
A1  - Willemsen, Pascale
T1  - Empirically investigating the concept of lying
JF  - Journal of Indian Council of Philosophical Research
N2  - Lying is an everyday moral phenomenon about which philosophers have written a lot. Not only the moral status of lying has been intensively discussed but also what it means to lie in the first place. Perhaps the most important criterion for an adequate definition of lying is that it fits with people’s understanding and use of this concept. In this light, it comes as a surprise that researchers only recently started to empirically investigate the folk concept of lying. In this paper, we describe three experimental studies which address the following questions: Does a statement need to be objectively false in order to constitute lying? Does lying necessarily include the intention to deceive? Can one lie by omitting relevant facts?
KW  - Concept of lying
KW  - Lying
KW  - Definition of lying
KW  - Experimental philosophy
Y1  - 2017
U6  - https://doi.org/10.1007/s40961-017-0112-z
SN  - 0970-7794
SN  - 2363-9962
VL  - 34
SP  - 591
EP  - 609
PB  - Springer
CY  - New Dehli
ER  - 
TY  - JOUR
A1  - Wiemann, Annika
A1  - Andersen, Liselotte W.
A1  - Berggren, Per
A1  - Siebert, Ursula
A1  - Benke, Harald
A1  - Teilmann, Jonay
A1  - Lockyer, Christina
A1  - Pawliczka, Iwona
A1  - Skora, Krysztof
A1  - Roos, Aanna
A1  - Lyrholm, Thomas
A1  - Paulus, Kirsten B.
A1  - Ketmaier, Valerio
T1  - Mitochondrial Control Region and microsatellite analyses on harbour porpoise (Phocoena phocoena) unravel population differentiation in the Baltic Sea and adjacent waters
N2  - The population status of the harbour porpoise (Phocoena phocoena) in the Baltic area has been a continuous matter of debate. Here we present the by far most comprehensive genetic population structure assessment to date for this region, both with regard to geographic coverage and sample size: 497 porpoise samples from North Sea, Skagerrak, Kattegat, Belt Sea, and Inner Baltic Sea were sequenced at the mitochondrial Control Region and 305 of these specimens were typed at 15 polymorphic microsatellite loci. Samples were stratified according to sample type (stranding vs. by- caught), sex, and season (breeding vs. non-breeding season). Our data provide ample evidence for a population split between the Skagerrak and the Belt Sea, with a transition zone in the Kattegat area. Among other measures, this was particularly visible in significant frequency shifts of the most abundant mitochondrial haplotypes. A particular haplotype almost absent in the North Sea was the most abundant in Belt Sea and Inner Baltic Sea. Microsatellites yielded a similar pattern (i.e., turnover in occurrence of clusters identified by STRUCTURE). Moreover, a highly significant association between microsatellite assignment and unlinked mitochondrial haplotypes further indicates a split between North Sea and Baltic porpoises. For the Inner Baltic Sea, we consistently recovered a small, but significant separation from the Belt Sea population. Despite recent arguments that separation should exceed a predefined threshold before populations shall be managed separately, we argue in favour of precautionary acknowledging the Inner Baltic porpoises as a separate management unit, which should receive particular attention, as it is threatened by various factors, in particular local fishery measures.
Y1  - 2010
UR  - http://www.springerlink.com/content/105709
U6  - https://doi.org/10.1007/s10592-009-0023-x
SN  - 1566-0621
ER  - 
TY  - JOUR
A1  - Wienhold, Sandra-Maria
A1  - Macri, Mario
A1  - Nouailles, Geraldine
A1  - Dietert, Kristina
A1  - Gurtner, Corinne
A1  - Gruber, Achim D.
A1  - Heimesaat, Markus M.
A1  - Lienau, Jasmin
A1  - Schumacher, Fabian
A1  - Kleuser, Burkhard
A1  - Opitz, Bastian
A1  - Suttorp, Norbert
A1  - Witzenrath, Martin
A1  - Müller-Redetzky, Holger C.
T1  - Ventilator-induced lung injury is aggravated by antibiotic mediated microbiota depletion in mice
JF  - Critical Care
N2  - BackgroundAntibiotic exposure alters the microbiota, which can impact the inflammatory immune responses. Critically ill patients frequently receive antibiotic treatment and are often subjected to mechanical ventilation, which may induce local and systemic inflammatory responses and development of ventilator-induced lung injury (VILI). The aim of this study was to investigate whether disruption of the microbiota by antibiotic therapy prior to mechanical ventilation affects pulmonary inflammatory responses and thereby the development of VILI.MethodsMice underwent 6-8weeks of enteral antibiotic combination treatment until absence of cultivable bacteria in fecal samples was confirmed. Control mice were housed equally throughout this period. VILI was induced 3 days after completing the antibiotic treatment protocol, by high tidal volume (HTV) ventilation (34ml/kg; positive end-expiratory pressure=2 cmH(2)O) for 4h. Differences in lung function, oxygenation index, pulmonary vascular leakage, macroscopic assessment of lung injury, and leukocyte and lymphocyte differentiation were assessed. Control groups of mice ventilated with low tidal volume and non-ventilated mice were analyzed accordingly.ResultsAntibiotic-induced microbiota depletion prior to HTV ventilation led to aggravation of VILI, as shown by increased pulmonary permeability, increased oxygenation index, decreased pulmonary compliance, enhanced macroscopic lung injury, and increased cytokine/chemokine levels in lung homogenates.ConclusionsDepletion of the microbiota by broad-spectrum antibiotics prior to HTV ventilation renders mice more susceptible to developing VILI, which could be clinically relevant for critically ill patients frequently receiving broad-spectrum antibiotics.
KW  - Broad-spectrum antibiotic therapy
KW  - Ventilator-induced lung injury
KW  - Microbiota
Y1  - 2018
U6  - https://doi.org/10.1186/s13054-018-2213-8
SN  - 1466-609X
SN  - 1364-8535
VL  - 22
IS  - 282
PB  - BMC
CY  - London
ER  - 
TY  - JOUR
A1  - Wiesner, Kerstin R.
A1  - Loxdale, Hugh D.
A1  - Köhler, Günter
A1  - Schneider, Anja R. R.
A1  - Tiedemann, Ralph
A1  - Weisser, Wolfgang W.
T1  - Patterns of local and regional genetic structuring in the meadow grasshopper, Chorthippus parallelus (Orthoptera: Acrididae), in Central Germany revealed using microsatellite markers
JF  - Biological journal of the Linnean Society : a journal of evolution
N2  - The meadow grasshopper, Chorthippus parallelus (Zetterstedt), is common and widespread in Central Europe, with a low dispersal range per generation. A population study in Central Germany (Frankenwald and Thuringer Schiefergebirge) showed strong interpopulation differences in abundance and individual fitness. We examined genetic variability using microsatellite markers within and between 22 populations in a short-to long-distance sampling (19 populations, Frankenwald, Schiefergebirge, as well as a southern transect), and in the Erzgebirge region (three populations), with the latter aiming to check for effects as a result of historical forest cover. Of the 671 C. parallelus captured, none was macropterous (functionally winged). All populations showed a high level of expected and observed heterozygosity (mean 0.80-0.90 and 0.60-0.75, respectively), whereas there was evidence of inbreeding (F(IS) values all positive). Allelic richness for all locus-population combinations was high (mean 9.3-11.2), whereas alleles per locus ranged from 15-62. At a local level, genic and genotypic differences were significant. Pairwise F(ST) values were in the range 0.00-0.04, indicating little interpopulation genetic differentiation. Similarly, the calculated gene flow was very high, based on the respective F(ST) (19.5) and using private alleles (7.7). A Neighbour-joining tree using Nei's D(A) and principal coordinate analysis separated two populations that were collected in the Erzgebirge region. Populations from this region may have escaped the effects of the historical forest cover. The visualization of the spatial arrangement of genotypes revealed one geographical barrier to gene flow in the short-distance sampling.
KW  - adaptation
KW  - gene flow
KW  - diversity
KW  - landscape structure
KW  - wing polyphenism
Y1  - 2011
U6  - https://doi.org/10.1111/j.1095-8312.2011.01698.x
SN  - 0024-4066
VL  - 103
IS  - 4
SP  - 875
EP  - 890
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Wiesner, Sebastian
A1  - Salmikangas, Paula
A1  - Auerbach, Daniel
A1  - Himmel, Mirko
A1  - Kempa, Stefan
A1  - Hayes, Kathrin
A1  - Pacholsky, Dirk
A1  - Taivainen, Anu
A1  - Schröder, Rolf
A1  - Carpen, Olli
A1  - Fürst, Dieter Oswald
T1  - Indications for a novel muscular dystrophy pathway : gamma-filamin, the muscle-specific filamin isoform, intgeracts with myotilin
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiethaus, Jessica
A1  - Mueller, Alexandra
A1  - Neumann, Meina
A1  - Neumann, Sandra
A1  - Leimkühler, Silke
A1  - Narberhaus, Franz
A1  - Masepohl, Bernd
T1  - Specific interactions between four Molybdenum-binding proteins contribute to Mo-dependent gene regulation in Rhodobacter capsulatus
N2  - The phototrophic purple bacterium Rhodobacter capsulatus encodes two transcriptional regulators, MopA and MopB, with partially overlapping and specific functions in molybdate-dependent gene regulation. Both MopA and MopB consist of an N-terminal DNA-binding helix-turn-helix domain and a C-terminal molybdate-binding di-MOP domain. They formed homodimers as apo-proteins and in the molybdate-bound state as shown by yeast two-hybrid (Y2H) studies, glutaraldehyde cross-linking, gel filtration chromatography, and copurification experiments. Y2H studies suggested that both the DNA- binding and the molybdate-binding domains contribute to dimer formation. Analysis of molybdate binding to MopA and MopB revealed a binding stoichiometry of four molybdate oxyanions per homodimer. Specific interaction partners of MopA and MopB were the molybdate transporter ATPase ModC and the molbindin-like Mop protein, respectively. Like other molbindins, the R. capsulatus Mop protein formed hexamers, which were stabilized by binding of six molybdate oxyanions per hexamer. Heteromer formation of MopA and MopB was shown by Y2H studies and copurification experiments. Reporter gene activity of a strictly MopA-dependent mop-lacZ fusion in mutant strains defective for either mopA, mopB, or both suggested that MopB negatively modulates expression of the mop promoter. We propose that depletion of the active MopA homodimer pool by formation of MopA-MopB heteromers might represent a fine-tuning mechanism controlling mop gene expression.
Y1  - 2009
UR  - http://jb.asm.org/
U6  - https://doi.org/10.1128/Jb.00526-09
SN  - 0021-9193
ER  - 
TY  - JOUR
A1  - Wildish, J.
A1  - Pavesi, Laura
A1  - Ketmaier, Valerio
T1  - Talitrid amphipods (Crustacea: Amphipoda: Talitridae) and the driftwood ecological niche  a morphological and molecular study
JF  - Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor & Francis   1.1967 -
N2  - Coastal regions of the North East Atlantic and Mediterranean Seas have four known species of driftwood talitrids. Records are extremely scanty, often limited to the type locality and dating to 1950. We were able to study three of them, all belonging to the genus Macarorchestia, using fresh and archived samples including type material. Allometric and molecular analyses support: (1) a close relationship among all the three classically defined Macarorchestia species, (2) Macarorchestia was well separated from non-driftwood taxa, and (3) a putative new driftwood talitrid discovered during this study was not closely related to Macarorchestia. Genetic divergence between the new species and Macarorchestia remyi is as high as the average distance among a number of talitrid species included in the study for comparison. A key is provided to identify all three of the presently known species of Macarorchestia, using morphological characters employed in the allometric study.
KW  - Macarorchestia remyi
KW  - Macarorchestia roffensis
KW  - Macarorchestia martini
KW  - Driftwood habitat
KW  - COI-DNA barcoding
KW  - allometry
Y1  - 2012
U6  - https://doi.org/10.1080/00222933.2012.717971
SN  - 0022-2933
VL  - 46
IS  - 43-44
SP  - 2677
EP  - 2700
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Wilke, Liza
A1  - Boeker, Sonja
A1  - Mumm, Rebecca
A1  - Groth, Detlef
T1  - The Social status influences human growth
BT  - A summary and analysis of historical data from German school girls in 1914 with comparison to modern references
JF  - Human biology and public health
N2  - Background: In the animal kingdom body size is often linked to dominance and subsequently the standing in social hierarchy. Similarly, human growth has been associated and linked to socioeconomic factors, including one’s social status. This has already been proposed in the early 1900s where data on young German school girls from different social strata have been compared.

Objectives: This paper aims to summarize and analyze these results and make them accessible for non-German speakers. The full English translation of the historic work of Dikanski (Dikanski, 1914) is available as a supplement. Further, this work aims to compare the historical data with modern references, to test three hypotheses: (1) higher social class is positively associated with body height and weight, (2) affluent people from the used historical data match modern references in weight and height and (3) weight distributions are skewed in both modern and historical populations.

Methods: Comparison of historical data from 1914 with WHO and 1980s German data. The data sets, for both body weight and height for 6.0- and 7.0-year-old girls, were fitted onto centile curves and quantile correlation coefficients were calculated.

Results: In historical data social status is positively associated with body height and weight while both are also normally distributed, which marks a significant difference to modern references.

Conclusion: Social status is positively associated with height, signaling social dominance, making children of affluent classes taller. Children from the historical data do not reach the average height of modern children, even under the best environmental conditions. The children of the upper social class were not skewed in weight distribution, although they had the means to become as obese as modern children.
KW  - Just so stories
KW  - Summer Schools
KW  - questioning solutions
KW  - repetition
Y1  - 2022
U6  - https://doi.org/10.52905/hbph2021.3.22
SN  - 2748-9957
VL  - 2021
IS  - 3, Summer School Supplement
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Willi, Yvonne
A1  - Fischer, Markus
T1  - Genetic rescue effect in interconnected populations of small and large size of the self-incompatible Ranunculus reptans
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Willi, Yvonne
A1  - van Buskirk, J.
A1  - Fischer, Markus
T1  - A threefold genetic allee effect : Population size affects cross-compatibility, inbreeding depression and drift load in the self-incompatible Ranunculus reptans
Y1  - 2005
SN  - 0016-6731
ER  - 
TY  - JOUR
A1  - Wilting, A.
A1  - Patel, R.
A1  - Pfestorf, Hans
A1  - Kern, C.
A1  - Sultan, K.
A1  - Ario, A.
A1  - Penaloza, F.
A1  - Kramer-Schadt, S.
A1  - Radchuk, Viktoriia
A1  - Foerster, D. W.
A1  - Fickel, Jörns
T1  - Evolutionary history and conservation significance of the Javan leopard Panthera pardus melas
JF  - Journal of zoology : proceedings of the Zoological Society of London
N2  - The leopard Panthera pardus is widely distributed across Africa and Asia; however, there is a gap in its natural distribution in Southeast Asia, where it occurs on the mainland and on Java but not on the interjacent island of Sumatra. Several scenarios have been proposed to explain this distribution gap. Here, we complemented an existing dataset of 68 leopard mtDNA sequences from Africa and Asia with mtDNA sequences (NADH5+ ctrl, 724bp) from 19 Javan leopards, and hindcasted leopard distribution to the Pleistocene to gain further insights into the evolutionary history of the Javan leopard. Our data confirmed that Javan leopards are evolutionarily distinct from other Asian leopards, and that they have been present on Java since the Middle Pleistocene. Species distribution projections suggest that Java was likely colonized via a Malaya-Java land bridge that by-passed Sumatra, as suitable conditions for leopards during Pleistocene glacial periods were restricted to northern and western Sumatra. As fossil evidence supports the presence of leopards on Sumatra at the beginning of the Late Pleistocene, our projections are consistent with a scenario involving the extinction of leopards on Sumatra as a consequence of the Toba super volcanic eruption (similar to 74kya). The impact of this eruption was minor on Java, suggesting that leopards managed to survive here. Currently, only a few hundred leopards still live in the wild and only about 50 are managed in captivity. Therefore, this unique and distinctive subspecies requires urgent, concerted conservation efforts, integrating insitu and ex situ conservation management activities in a One Plan Approach to species conservation management.
KW  - biogeography
KW  - evolutionary history
KW  - Felidae
KW  - Southeast Asia
KW  - Toba eruption
KW  - One Plan Approach
KW  - Pleistocene
KW  - Javan leopard
Y1  - 2016
U6  - https://doi.org/10.1111/jzo.12348
SN  - 0952-8369
SN  - 1469-7998
VL  - 299
SP  - 239
EP  - 250
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wimmelbacher, Matthias
A1  - Börnke, Frederik
T1  - Redox activity of thioredoxin z and fructokinase-like protein 1 is dispensable for autotrophic growth of Arabidopsis thaliana
JF  - Journal of experimental botany
N2  - Redox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C(105/106)A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, our data support a model in which TRX z and FLN1 are essential structural components of the PEP complex and their redox activity might only play a role in the fine tuning of PEP function.
KW  - Chloroplast transcription
KW  - FLN1
KW  - plastid-encoded RNA polymerase
KW  - redox regulation
KW  - thioredoxins
KW  - TRX z
Y1  - 2014
U6  - https://doi.org/10.1093/jxb/eru122
SN  - 0022-0957
SN  - 1460-2431
VL  - 65
IS  - 9
SP  - 2405
EP  - 2413
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Winck, Flavia V.
A1  - Riano-Pachon, Diego M.
A1  - Sommer, Frederik
A1  - Rupprecht, Jens
A1  - Müller-Röber, Bernd
T1  - The nuclear proteome of the green alga Chlamydomonas reinhardtii
JF  - Proteomics
N2  - Nuclear proteins play a central role in regulating gene expression. Their identification is important for understanding how the nuclear repertoire changes over time under different conditions. Nuclear proteins are often underrepresented in proteomic studies due to the frequently low abundance of proteins involved in regulatory processes. So far, only few studies describing the nuclear proteome of plant species have been published. Recently, the genome sequence of the unicellular green alga Chlamydomonas reinhardtii has been obtained and annotated, allowing the development of further detailed studies for this organism. However, a detailed description of its nuclear proteome has not been reported so far. Here, we present an analysis of the nuclear proteome of the sequenced Chlamydomonas strain cc503. Using LC-MS/MS, we identified 672 proteins from nuclei isolates with a maximum 1% peptide spectrum false discovery rate. Besides well-known proteins (e.g. histones), transcription factors and other transcriptional regulators (e.g. tubby and HMG) were identified. The presence of protein motifs in nuclear proteins was investigated by computational tools, and specific over-represented protein motifs were identified. This study provides new insights into the complexity of the nuclear environment and reveals novel putative protein targets for further studies of nuclear mechanisms.
KW  - Nuclear proteomics
KW  - Plant proteomics
KW  - Systems biology
KW  - Transcription factor
Y1  - 2012
U6  - https://doi.org/10.1002/pmic.201000782
SN  - 1615-9853
VL  - 12
IS  - 1
SP  - 95
EP  - 100
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Winck, Flavia Vischi
A1  - Arvidsson, Samuel Janne
A1  - Mauricio Riano-Pachon, Diego
A1  - Hempel, Sabrina
A1  - Koseska, Aneta
A1  - Nikoloski, Zoran
A1  - Urbina Gomez, David Alejandro
A1  - Rupprecht, Jens
A1  - Müller-Röber, Bernd
T1  - Genome-wide identification of regulatory elements and reconstruction of gene regulatory networks of the green alga chlamydomonas reinhardtii under carbon deprivation
JF  - PLoS one
N2  - The unicellular green alga Chlamydomonas reinhardtii is a long-established model organism for studies on photosynthesis and carbon metabolism-related physiology. Under conditions of air-level carbon dioxide concentration [CO2], a carbon concentrating mechanism (CCM) is induced to facilitate cellular carbon uptake. CCM increases the availability of carbon dioxide at the site of cellular carbon fixation. To improve our understanding of the transcriptional control of the CCM, we employed FAIRE-seq (formaldehyde-assisted Isolation of Regulatory Elements, followed by deep sequencing) to determine nucleosome-depleted chromatin regions of algal cells subjected to carbon deprivation. Our FAIRE data recapitulated the positions of known regulatory elements in the promoter of the periplasmic carbonic anhydrase (Cah1) gene, which is upregulated during CCM induction, and revealed new candidate regulatory elements at a genome-wide scale. In addition, time series expression patterns of 130 transcription factor (TF) and transcription regulator (TR) genes were obtained for cells cultured under photoautotrophic condition and subjected to a shift from high to low [CO2]. Groups of co-expressed genes were identified and a putative directed gene-regulatory network underlying the CCM was reconstructed from the gene expression data using the recently developed IOTA (inner composition alignment) method. Among the candidate regulatory genes, two members of the MYB-related TF family, Lcr1 (Low-CO2 response regulator 1) and Lcr2 (Low-CO2 response regulator 2), may play an important role in down-regulating the expression of a particular set of TF and TR genes in response to low [CO2]. The results obtained provide new insights into the transcriptional control of the CCM and revealed more than 60 new candidate regulatory genes. Deep sequencing of nucleosome-depleted genomic regions indicated the presence of new, previously unknown regulatory elements in the C. reinhardtii genome. Our work can serve as a basis for future functional studies of transcriptional regulator genes and genomic regulatory elements in Chlamydomonas.
Y1  - 2013
U6  - https://doi.org/10.1371/journal.pone.0079909
SN  - 1932-6203
VL  - 8
IS  - 11
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Winck, Flavia Vischi
A1  - Kwasniewski, Miroslaw
A1  - Wienkoop, Stefanie
A1  - Müller-Röber, Bernd
T1  - An optimized method for the isolation of nuclei from chlamydomas Reinhardtii (Chlorophyceae)
JF  - Journal of phycology
N2  - The cell nucleus harbors a large number of proteins involved in transcription, RNA processing, chromatin remodeling, nuclear signaling, and ribosome assembly. The nuclear genome of the model alga Chlamydomonas reinhardtii P. A. Dang. was recently sequenced, and many genes encoding nuclear proteins, including transcription factors and transcription regulators, have been identified through computational discovery tools. However, elucidating the specific biological roles of nuclear proteins will require support from biochemical and proteomics data. Cellular preparations with enriched nuclei are important to assist in such analyses. Here, we describe a simple protocol for the isolation of nuclei from Chlamydomonas, based on a commercially available kit. The modifications done in the original protocol mainly include alterations of the differential centrifugation parameters and detergent-based cell lysis. The nuclei-enriched fractions obtained with the optimized protocol show low contamination with mitochondrial and plastid proteins. The protocol can be concluded within only 3 h, and the proteins extracted can be used for gel-based and non-gel-based proteomic approaches.
KW  - 2D gel electrophoresis
KW  - algae
KW  - Chlamydomonas
KW  - nuclear proteins
KW  - nucleus
KW  - proteomics
Y1  - 2011
U6  - https://doi.org/10.1111/j.1529-8817.2011.00967.x
SN  - 0022-3646
VL  - 47
IS  - 2
SP  - 333
EP  - 340
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
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 is 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 1m2. 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 population-pattern 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 sum of squares. These sums of squares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25cm×25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sum of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1-2m was indispensable for explaining the observed population spread that led to distances of at most 8mfrom population origin within 3 years. Projections of population development over four 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.
Y1  - 2007
UR  - http://www.sciencedirect.com/science/journal/03043800
SN  - 0304-3800
ER  -