Biology subjects

Foerster, D. W.

Publications and source records attributed to Foerster, D. W..

4 recordsLinked to original sources

bioRxiv2025

Genomics of sable (Martes zibellina) x pine marten (Martes martes) hybridization

The sable (Martes zibellina) and pine marten (Martes martes) are two Palearctic mustelids with long-recognized hybrids (kidases), whose fertility was controversial for years. Early genetic studies confirmed hybrids beyond F1, but details remained unclear due to low-resolution methods. Both species were hunted for centuries, but anthropogenic pressures during the 20th-century caused severe bottlenecks in the sable followed by hunting bans and large-scale reintroduction programs across much of its range, including the sympatric zone, potentially affecting hybridization. We resequenced 30 individuals from most of the sables range and Eastern part of pine martens. Among samples, we found a broad spectrum of hybrid types with mosaic recombinant chromosomes that confirm hybrid fertility and indicate crossover is not suppressed in kidases. This necessitates re-evaluation of previous research, as we detected notable discrepancies between STR-based ancestry and whole-genome analysis. In pine martens, we revealed mitochondrial DNA introgression from sables, indicating displacement of native pine marten mitochondrial sequences. Pine marten heterozygosity is relatively low ([~]0.5-0.6 hetSNPs/kbp) while sable diversity ([~]1.5-1.8 hetSNPs/kbp) is unexpectedly high for a species with its demographic history, likely reflecting successful reintroduction programs. We dated species divergence at 1.52 (CI: 1.05-2.06) Mya and identified candidate genes associated with ecological, morphological, and dietary differences, as well as hybrid fertility issues. This study is the first to elucidate marten hybridization at the whole-genome level, opening new research directions for understanding hybridization among Holarctic martens, the genetic consequences of reintroduction programs, and comparative adaptomics.

genomics↗

bioRxiv2025

Comparative genomics and phylogenomics of the Mustelinae lineage (Mustelidae, Carnivora)

Mustelinae are among the most diverse and taxonomically complex subfamilies within the Mustelidae, yet their evolutionary history and genetic diversity remain largely unexplored at the whole-genome level. Here, we present the first comprehensive comparative and phylogenomic study of this lineage, integrating nuclear and mitochondrial genomes from ten species across the Holarctic and Indomalayan realms. Our dataset includes two novel genome assemblies (Mustela strigidorsa, M. sibirica) and an improved genome for M. nivalis, enabling robust cross-species analyses of genome size, chromosomal evolution, genetic diversity, and demographic history. We uncover striking inter-and intraspecific variation in genome-wide heterozygosity and genome size, with evidence of marked homozygosity in some Asian lineages (M. eversmanii, M. sibirica, M. strigidorsa) and remarkable genetic diversity in widespread species such as M. nivalis and M. erminea. Phylogenomic results support the previously suggested split of M. richardsonii from M. erminea, but we found no evidence for speciation within M. nivalis. Ancestral reconstruction of chromosomal rearrangements revealed key chromosomal fissions that shaped the Mustelinae radiation, including early events predating the divergence of modern Mustela species. The results confirmed the ancestral karyotype of Mustela (2n=44) and the Mustelinae (2n=42). Finally, demographic reconstructions exposed species-specific responses to Quaternary climatic cycles, ranging from long-term resilience in M. nivalis to repeated population bottlenecks in M. putorius and M. sibirica. Collectively, our findings establish a genomic foundation for future evolutionary and conservation genomic research on this emblematic Mustelidae lineage.

evolutionary biology↗

bioRxiv2022

First mitogenome phylogeny of the sun bear Helarctos malayanus reveals a deep split between Indochinese and Sundaic lineages

The sun bear Helarctos malayanus is one of the most endangered ursids, and to date classification of sun bear populations has been based almost exclusively on geographic distribution and morphology. The very few molecular studies focusing on this species were limited in geographic scope. Using archival and non-invasively collected sample material, we have added a substantial number of complete or near-complete mitochondrial genome sequences from sun bears of several range countries of the species distribution. We here report 32 new mitogenome sequences representing sun bears from Cambodia, Thailand, Peninsular Malaysia, Sumatra and Borneo. Reconstruction of phylogenetic relationships revealed two matrilines that diverged [~]290 thousand years ago: one restricted to portions of mainland Indochina (China, Cambodia, Thailand; "Mainland clade"), and one comprising bears from Borneo, Sumatra, Peninsular Malaysia but also Thailand ("Sunda clade"). Generally recent coalescence times in the mitochondrial phylogeny suggest that recent or historical demographic processes have resulted in a loss of mtDNA variation. Additionally, analysis of our data in conjunction with shorter mtDNA sequences revealed that the Bornean sun bear, classified as a distinct subspecies (H. m. euryspilus), does not harbour a distinctive matriline. Further molecular studies of H. malayanus are needed, which should ideally include data from nuclear loci.

genomics↗

bioRxiv2018

Historical biogeography of the leopard (Panthera pardus) and its extinct Eurasian populations

BackgroundResolving the historical biogeography of the leopard (Panthera pardus) is a complex issue, because patterns inferred from fossils and from molecular data lack congruence. Fossil evidence supports an African origin, and suggests that leopards were already present in Eurasia during the Early Pleistocene. Analysis of DNA sequences however, suggests a more recent, Middle Pleistocene shared ancestry of Asian and African leopards. These contrasting patterns led researchers to propose a two-stage hypothesis of leopard dispersal out of Africa: an initial Early Pleistocene colonisation of Asia and a subsequent replacement by a second colonisation wave during the Middle Pleistocene. The status of Late Pleistocene European leopards within this scenario is unclear: were these populations remnants of the first dispersal, or do the last surviving European leopards share more recent ancestry with their African counterparts?\n\nResultsIn this study, we generate and analyse mitogenome sequences from historical samples that span the entire modern leopard distribution, as well as from Late Pleistocene remains. We find a deep bifurcation between African and Eurasian mitochondrial lineages ([~]710 Ka), with the European ancient samples as sister to all Asian lineages ([~]483 Ka). The modern and historical mainland Asian lineages share a relatively recent common ancestor ([~]122 Ka), and we find one Javan sample nested within these.\n\nConclusionsThe phylogenetic placement of the ancient European leopard as sister group to Asian leopards suggests that these populations originate from the same out-of-Africa dispersal which founded the Asian lineages. The coalescence time found for the mitochondrial lineages aligns well with the earliest undisputed fossils in Eurasia, and thus encourages a re-evaluation of the identification of the much older putative leopard fossils from the region. The relatively recent ancestry of all mainland Asian leopard lineages suggests that these populations underwent a severe population bottleneck during the Pleistocene. Finally, although only based on a single sample, the unexpected phylogenetic placement of the Javan leopard could be interpreted as evidence for exchange of mitochondrial lineages between Java and mainland Asia, calling for further investigation into the evolutionary history of this subspecies.

evolutionary biology↗