Biology subjects

Ursenbacher, S.

Publications and source records attributed to Ursenbacher, S..

2 recordsLinked to original sources

bioRxiv2024

Unveiling the evolutionary history of European vipers and their venoms from a multi-omic approach

Snake genomes attract significant attention from multiple disciplines, including medicine, drug bioprospection, and evolutionary biology, due to the unique features found in snakes, especially, the evolution of venom. However, genomic research within the family Viperidae has mostly focused to date on the subfamily Crotalinae, while overlooking Viperinae, the Old World vipers. Among Viperinae, European vipers (Vipera) have been the subject of extensive research because of their venoms, phylogeographic, and ecological diversification. Nevertheless, venom research in this group has been conducted using mostly proteomes alone, while phylogeography and systematics in the genus have relied on biased information from mitochondrial phylogenies. Here, we generated chromosome-level genome assemblies for three Vipera species and whole-genome sequencing data for 94 samples representing 15 Vipera taxa. This comprehensive dataset has enabled us to disentangle the phylogenomic relationships of this genus, affected by mito-nuclear discordance and pervaded by ancestral introgression. Population-level analyses in the Iberian Peninsula, where the three oldest lineages within Vipera meet, revealed signals of recent adaptive introgression between ecologically dissimilar species, whereas chromosomal rearrangements isolate species occupying similar niches. Finally, using transcriptomic and proteomic data, we characterized the Vipera toxin-encoding genes, in which opposing selective forces were unveiled as common drivers of the evolution of venom as an integrated phenotype.

genomics↗

bioRxiv2022

Hotspots for snake fungal disease across Europe are maintained by host and pathogen identity

1. Infectious diseases are influenced by interactions between host and pathogen, and are rarely homogenous across the landscape. Areas with elevated pathogen prevalence maintain a high force of infection, can facilitate pathogen spread to new regions, and may indicate areas with impacts on host populations. However, isolating the ecological processes that result in increases in infection prevalence and intensity remains a challenge. 2. Here we elucidate the contribution of pathogen clade and host species in disease hotspots of Ophidiomyces ophidiicola, the pathogen that causes snake fungal disease, in 21 species of snakes infected with multiple pathogen strains across 10 countries in Europe. 3. We found isolated areas of disease hotspots in a landscape where infections were otherwise low. O. ophidiicola clade had important effects on transmission, and areas with multiple pathogen clades had higher host infection prevalence. Snake species identity further influenced infection, with most positive detections coming from the Natrix genus. Most species present in the community only experienced increased levels of infection when multiple strains were present. However, one species, N. tessellata, appeared highly susceptible, having increased infection prevalence regardless of pathogen strain, indicating that this species may be important in pathogen maintenance. 4. Our results suggest that both host and pathogen identity are essential components contributing to increased pathogen prevalence. More broadly, our findings indicate that coevolutionary relationships between hosts and pathogens may be key mechanisms explaining variation in landscape patterns of disease.

ecology↗