TY - JOUR A1 - Sammler, Svenja A1 - Bleidorn, Christoph A1 - Tiedemann, Ralph T1 - Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination JF - BMC genomics N2 - Background: Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results: Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i. e., in every generation. Conclusions: The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB is supposed to halt replication, it offers a potential mechanistic explanation for frequent recombination in mitochondrial genomes. Y1 - 2011 U6 - https://doi.org/10.1186/1471-2164-12-35 SN - 1471-2164 VL - 12 IS - 2 PB - BioMed Central CY - London ER - TY - JOUR A1 - Schedina, Ina Maria A1 - Groth, Detlef A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - The gonadal transcriptome of the unisexual Amazon molly Poecilia formosa in comparison to its sexual ancestors, Poecilia mexicana and Poecilia latipinna JF - BMC Genomics N2 - Background The unisexual Amazon molly (Poecilia formosa) originated from a hybridization between two sexual species, the sailfin molly (Poecilia latipinna) and the Atlantic molly (Poecilia mexicana). The Amazon molly reproduces clonally via sperm-dependent parthenogenesis (gynogenesis), in which the sperm of closely related species triggers embryogenesis of the apomictic oocytes, but typically does not contribute genetic material to the next generation. We compare for the first time the gonadal transcriptome of the Amazon molly to those of both ancestral species, P. mexicana and P. latipinna. Results We sequenced the gonadal transcriptomes of the P. formosa and its parental species P. mexicana and P. latipinna using Illumina RNA-sequencing techniques (paired-end, 100 bp). De novo assembly of about 50 million raw read pairs for each species was performed using Trinity, yielding 106,922 transcripts for P. formosa, 115,175 for P. latipinna, and 133,025 for P. mexicana after eliminating contaminations. On the basis of sequence similarity comparisons to other teleost species and the UniProt databases, functional annotation, and differential expression analysis, we demonstrate the similarity of the transcriptomes among the three species. More than 40% of the transcripts for each species were functionally annotated and about 70% were assigned to orthologous genes of a closely related species. Differential expression analysis between the sexual and unisexual species uncovered 2035 up-regulated and 564 down-regulated genes in P. formosa. This was exemplary validated for six genes by qRT-PCR. Conclusions We identified more than 130 genes related to meiosis and reproduction within the apomictically reproducing P. formosa. Overall expression of these genes seems to be down-regulated in the P. formosa transcriptome compared to both ancestral species (i.e., 106 genes down-regulated, 29 up-regulated). A further 35 meiosis and reproduction related genes were not found in the P. formosa transcriptome, but were only expressed in the sexual species. Our data support the hypothesis of general down-regulation of meiosis-related genes in the apomictic Amazon molly. Furthermore, the obtained dataset and identified gene catalog will serve as a resource for future research on the molecular mechanisms behind the reproductive mode of this unisexual species. KW - Differential gene expression KW - Gynogenesis KW - Hybrid speciation KW - Meiosis KW - Poecilia formosa KW - Poecilia latipinna KW - Poecilia mexicana Y1 - 2018 U6 - https://doi.org/10.1186/s12864-017-4382-2 SN - 1471-2164 VL - 19 IS - 12 SP - 1 EP - 18 PB - BioMed Central CY - London ER - TY - JOUR A1 - Makowicz, Amber M. A1 - Tiedemann, Ralph A1 - Steele, Rachel N. A1 - Schlupp, Ingo T1 - Kin Recognition in a Clonal Fish, Poecilia formosa JF - PLoS one N2 - Relatedness strongly influences social behaviors in a wide variety of species. For most species, the highest typical degree of relatedness is between full siblings with 50% shared genes. However, this is poorly understood in species with unusually high relatedness between individuals: clonal organisms. Although there has been some investigation into clonal invertebrates and yeast, nothing is known about kin selection in clonal vertebrates. We show that a clonal fish, the Amazon molly (Poecilia formosa), can distinguish between different clonal lineages, associating with genetically identical, sister clones, and use multiple sensory modalities. Also, they scale their aggressive behaviors according to the relatedness to other females: they are more aggressive to non-related clones. Our results demonstrate that even in species with very small genetic differences between individuals, kin recognition can be adaptive. Their discriminatory abilities and regulation of costly behaviors provides a powerful example of natural selection in species with limited genetic diversity. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0158442 SN - 1932-6203 VL - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Scherer, Ulrike A1 - Tiedemann, Ralph A1 - Schlupp, Ingo T1 - Male size, not female preferences influence female reproductive success in a poeciliid fish (Poecilia latipinna) BT - a combined behavioural/genetic approach JF - BMC Research Notes N2 - Objective We investigated the potential role of indirect benefits for female mate preferences in a highly promiscuous species of live-bearing fishes, the sailfin molly Poecilia latipinna using an integrative approach that combines methods from animal behavior, life-history evolution, and genetics. Males of this species solely contribute sperm for reproduction, and consequently females do not receive any direct benefits. Despite this, females typically show clear mate preferences. It has been suggested that females can increase their reproductive success through indirect benefits from choosing males of higher quality. Results Although preferences for large body size have been recorded as an honest signal for genetic quality, this particular study resulted in female preference being unaffected by male body size. Nonetheless, larger males did sire more offspring, but with no effect on offspring quality. This study presents a methodical innovation by combining preference testing with life history measurements—such as the determination of the dry weight of fish embryos—and paternity analyses on single fish embryos. KW - Fitness KW - Life history KW - Mate choice KW - Microsatellite analysis KW - Offspring weight KW - Paternity analysis KW - Sailfin molly KW - Sexual selection Y1 - 2018 U6 - https://doi.org/10.1186/s13104-018-3487-2 SN - 1756-0500 VL - 11 IS - 364 SP - 1 EP - 5 PB - Biomed Central CY - London ER - TY - JOUR A1 - Dominguez, Marisol A1 - Tiedemann, Ralph A1 - Reboreda, Juan C. A1 - Segura, Luciano A1 - Tittarelli, Fabian A1 - Mahler, Bettina T1 - Genetic structure reveals management units for the yellow cardinal (Gubernatrix cristata), endangered by habitat loss and illegal trapping JF - Conservation genetics KW - Genetic structure KW - Gubernatrix cristata KW - Management units KW - MtDNA KW - Microsatellites KW - Hybrids Y1 - 2017 U6 - https://doi.org/10.1007/s10592-017-0964-4 SN - 1566-0621 SN - 1572-9737 VL - 18 SP - 1131 EP - 1140 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Di Giacomo, Adrian S. A1 - Di Giacomo, Alejandro G. A1 - Kliger, Rafi A1 - Reboreda, Juan C. A1 - Tiedemann, Ralph A1 - Mahler, Bettina T1 - No evidence of genetic variation in microsatellite and mitochondrial DNA markers among remaining populations of the Strange-tailed Tyrant Alectrurus risora, an endangered grassland species JF - Bird conservation international N2 - The Strange-tailed Tyrant Alectrurus risora (Aves: Tyrannidae) is an endemic species of southern South American grasslands that suffered a 90% reduction of its original distribution due to habitat transformation. This has led the species to be classified as globally Vulnerable. By the beginning of the last century, populations were partially migratory and moved south during the breeding season. Currently, the main breeding population inhabits the Ibera wetlands in the province of Corrientes, north-east Argentina, where it is resident all year round. There are two remaining small populations in the province of Formosa, north-east Argentina, and in southern Paraguay, which are separated from the main population by the Parana-Paraguay River and its continuous riverine forest habitat. The populations of Corrientes and Formosa are separated by 300 km and the grasslands between populations are non-continuous due to habitat transformation. We used mtDNA sequences and eight microsatellite loci to test if there were evidences of genetic isolation between Argentinean populations. We found no evidence of genetic structure between populations (Phi(ST) = 0.004, P = 0.32; Fst = 0.01, P = 0.06), which can be explained by either retained ancestral polymorphism or by dispersal between populations. We found no evidence for a recent demographic bottleneck in nuclear loci. Our results indicate that these populations could be managed as a single conservation unit on a regional scale. Conservation actions should be focused on preserving the remaining network of areas with natural grasslands to guarantee reproduction, dispersal and prevent further decline of populations. Y1 - 2015 U6 - https://doi.org/10.1017/S0959270914000203 SN - 0959-2709 SN - 1474-0001 VL - 25 IS - 2 SP - 127 EP - 138 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Dolgener, Nicola A1 - Freudenberger, L. A1 - Schneeweiss, N. A1 - Ibisch, P. L. A1 - Tiedemann, Ralph T1 - Projecting current and potential future distribution of the Fire-bellied toad Bombina bombina under climate change in north-eastern Germany JF - Regional environmental change N2 - Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads. KW - Brandenburg KW - Climate change KW - Distribution modelling KW - Endangered species KW - Fire-bellied toad KW - Maxent Y1 - 2014 U6 - https://doi.org/10.1007/s10113-013-0468-9 SN - 1436-3798 SN - 1436-378X VL - 14 IS - 3 SP - 1063 EP - 1072 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Dolgener, N. A1 - Freudenberger, L. A1 - Schluck, M. A1 - Schneeweiss, N. A1 - Ibisch, P. L. A1 - Tiedemann, Ralph T1 - Environmental niche factor analysis (ENFA) relates environmental parameters to abundance and genetic diversity in an endangered amphibian, the fire-bellied-toad (Bombina bombina) JF - Conservation genetics N2 - Increasing attempts are made to understand the factors responsible for both the demographic and genetic depletion in amphibian populations. Landscape genetics aims at a spatially explicit correlation of genetic population parameters to landscape features. Using data from the endangered fire-bellied toad Bombina bombina in Brandenburg (Northeastern Germany), we performed an environmental niche factor analysis (ENFA), relating demographic (abundance) and genetic (diversity at 17 microsatellite loci and partial sequences of the mitochondrial control region in 434 individuals from 16 populations) parameters to ecological and anthropogenic variables such as temperature, precipitation, soil wetness, water runoff, vegetation density, and road/traffic impact. We found significant correlations between road disturbance and observed heterozygosity and between soil wetness and mitochondrial diversity. As the influences of the environmental variables can differ between different indicators for genetic diversity, population size and abundance data, our ENFA-based landscape genetics approach allows us to put various aspects of long- versus short term effective population size and genetic connectivity into an ecological and spatially explicit context, enabling potentially even forecast assessment under future environmental scenarios. KW - Distribution modelling KW - ENFA KW - Genetic diversity KW - Fire-bellied toad KW - Landscape genetics KW - Road disturbance Y1 - 2014 U6 - https://doi.org/10.1007/s10592-013-0517-4 SN - 1566-0621 SN - 1572-9737 VL - 15 IS - 1 SP - 11 EP - 21 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Paraskevopoulou, Sofia A1 - Dennis, Alice B. A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers JF - Scientific Reports N2 - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming. KW - Ecology KW - Evolution KW - Oyster Crassostrea-gigas KW - cryptic species complex KW - pacific oyster KW - thermal-stress KW - genetic differentiation KW - expression patterns KW - molecular phylogeny KW - shock proteins KW - evolutionary KW - hsp70 Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-70173-0 SN - 2045-2322 VL - 10 PB - Macmillan Publishers Limited, part of Springer Nature CY - London ER - TY - JOUR A1 - Colangeli, Pierluigi A1 - Schlägel, Ulrike E. A1 - Obertegger, Ulrike A1 - Petermann, Jana S. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Negative phototactic response to UVR in three cosmopolitan rotifers: a video analysis approach JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica KW - Risk avoidance behavior KW - Brachionus calyciflorus KW - Keratella cochlearis KW - BEMOVI KW - Movement ecology Y1 - 2018 U6 - https://doi.org/10.1007/s10750-018-3801-y SN - 0018-8158 SN - 1573-5117 VL - 844 IS - 1 SP - 43 EP - 54 PB - Springer CY - Dordrecht ER -