TY - JOUR A1 - Kiemel, Katrin A1 - De Cahsan, Binia A1 - Paraskevopoulou, Sofia A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Mitochondrial genomes of the freshwater monogonont rotifer Brachionus fernandoi and of two additional B. calyciflorus sensu stricto lineages from Germany and the USA (Rotifera, Brachionidae) JF - Mitochondrial DNA. Part B-Resources N2 - The Brachionus calyciflorus species complex was recently subdivided into four species, but genetic resources to resolve phylogenetic relationships within this complex are still lacking. We provide two complete mitochondrial (mt) genomes from B. calyciflorus sensu stricto (Germany, USA) and the mt coding sequences (cds) from a German B. fernandoi. Phylogenetic analysis placed our B. calyciflorus sensu stricto strains close to the published genomes of B. calyciflorus, forming the putative sister species to B. fernandoi. Global representatives of B. calyciflorus sensu stricto (i.e. Europe, USA, and China) are genetically closer related to each other than to B. fernandoi (average pairwise nucleotide diversity 0.079 intraspecific vs. 0.254 interspecific). KW - Mitogenome KW - cryptic species KW - Brachionus calyciflorus s KW - Brachionus KW - fernandoi KW - monogonont rotifer Y1 - 2022 U6 - https://doi.org/10.1080/23802359.2022.2060765 SN - 2380-2359 VL - 7 IS - 4 SP - 646 EP - 648 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR 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 JF - Scientific reports 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. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-27137-3 SN - 2045-2322 VL - 12 IS - 1 PB - Macmillan Publishers Limited CY - London ER - TY - JOUR A1 - Kiemel, Katrin A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - DNA metabarcoding reveals impact of local recruitment, dispersal, and hydroperiod on assembly of a zooplankton metacommunity JF - Molecular ecology N2 - Understanding the environmental impact on the assembly of local communities in relation to their spatial and temporal connectivity is still a challenge in metacommunity ecology. This study aims to unravel underlying metacommunity processes and environmental factors that result in observed zooplankton communities. Unlike most metacommunity studies, we jointly examine active and dormant zooplankton communities using a DNA metabarcoding approach to overcome limitations of morphological species identification. We applied two-fragment (COI and 18S) metabarcoding to monitor communities of 24 kettle holes over a two-year period to unravel (i) spatial and temporal connectivity of the communities, (ii) environmental factors influencing local communities, and (iii) dominant underlying metacommunity processes in this system. We found a strong separation of zooplankton communities from kettle holes of different hydroperiods (degree of permanency) throughout the season, while the community composition within single kettle holes did not differ between years. Species richness was primarily dependent on pH and permanency, while species diversity (Shannon Index) was influenced by kettle hole location. Community composition was impacted by kettle hole size and surrounding field crops. Environmental processes dominated temporal and spatial processes. Sediment communities showed a different composition compared to water samples but did not differ between ephemeral and permanent kettle holes. Our results suggest that communities are mainly structured by environmental filtering based on pH, kettle hole size, surrounding field crops, and permanency. Environmental filtering based on specific conditions in individual kettle holes seems to be the dominant process in community assembly in the studied zooplankton metacommunity. KW - bulk DNA KW - dispersal KW - DNA-metabarcoding KW - environmental filtering; KW - metacommunity KW - zooplankton Y1 - 2022 U6 - https://doi.org/10.1111/mec.16627 SN - 0962-1083 SN - 1365-294X VL - 32 IS - 23 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Stiegler, Jonas A1 - Kiemel, Katrin A1 - Eccard, Jana A1 - Fischer, Christina A1 - Hering, Robert A1 - Ortmann, Sylvia A1 - Strigl, Lea A1 - Tiedemann, Ralph A1 - Ullmann, Wiebke A1 - Blaum, Niels T1 - Seed traits matter BT - endozoochoric dispersal through a pervasive mobile linker JF - Ecology and evolution 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. KW - agricultural landscapes KW - endozoochory KW - Lepus europaeus KW - mobile links KW - seed dispersal KW - seed dispersal syndrome Y1 - 2021 U6 - https://doi.org/10.1002/ece3.8440 SN - 2045-7758 VL - 11 IS - 24 SP - 18477 EP - 18491 PB - Wiley CY - Hoboken ER - TY - JOUR 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 JF - Scientific Reports 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. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-27137-3 SN - 2045-2322 VL - 12 PB - Springer Nature CY - London ER - TY - JOUR 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 JF - Ecology and Evolution 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. KW - agricultural landscapes KW - endozoochory KW - Lepus europaeus KW - mobile links KW - seed dispersal KW - seed dispersal syndrome Y1 - 2021 U6 - https://doi.org/10.1002/ece3.8440 SN - 2045-7758 VL - 11 IS - 24 SP - 18477 EP - 18491 PB - John Wiley & Sons, Inc. ER - TY - JOUR 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 JF - Ecology and Evolution 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. KW - Bombina bombina KW - heat shock protein KW - introgression KW - major histocompatibility complex KW - scaled mass index Y1 - 2021 SN - 2045-7758 VL - 11 IS - 14 PB - John Wiley & Sons, Inc. CY - New Jersey ER -