Biology subjects

Kowalczyk, R.

Publications and source records attributed to Kowalczyk, R..

3 recordsLinked to original sources

bioRxiv2025

Immune Signatures of Gastrointestinal Helminth Infection in Transcriptomes of European Bison

Understanding the genes and molecular pathways that shape host responses to infection is essential for advancing our knowledge of host-parasite interactions and their ecological and evolutionary implications. Such insights are especially valuable for conserving endangered species that may be vulnerable to emerging or novel pathogens. Here, we investigated the impact of the recently introduced gastrointestinal nematode Ashworthius sidemi on gene expression in its novel host, the European bison (Bison bonasus). We analyzed abomasal transcriptomes (n = 45) from individuals characterized by a wide range of infection intensities (0-8,620 parasites per host). Despite substantial variation in parasite burden, differential expression analyses detected no individual genes significantly associated with infection intensity. However, gene set enrichment analyses based on p-value distributions revealed multiple immune-related gene ontology categories, including B and T cell activation, neutrophil chemotaxis, inflammatory responses, and regulation of IL-6 production. These findings indicate that European bison mount a clear yet subtle transcriptional response to A. sidemi infection and highlight molecular pathways potentially involved in mediating host defense against this emerging parasite.

immunology↗

bioRxiv2020

Next-generation phylogeography resolves post-glacial colonization patterns in a widespread carnivore, the red fox (Vulpes vulpes), in Europe.

Carnivores tend to exhibit a lack of (or less pronounced) genetic structure at continental scales in both a geographic and temporal sense and this can confound the identification of post-glacial colonization patterns in this group. In this study we used genome-wide data (using Genotyping-by-Sequencing (GBS)) to reconstruct the phylogeographic history of a widespread carnivore, the red fox (Vulpes vulpes), by investigating broad-scale patterns of genomic variation, differentiation and admixture amongst contemporary populations in Europe. Using 15,003 single nucleotide polymorphisms (SNPs) from 524 individuals allowed us to identify the importance of refugial regions for the red fox in terms of endemism (e.g. Iberia). In addition, we tested multiple post-glacial re-colonization scenarios of previously glaciated regions during the Last Glacial Maximum using an Approximate Bayesian Computation (ABC) approach that were unresolved from previous studies. This allowed us to identify the role of admixture from multiple source population post-Younger Dryas in the case of Scandinavia and ancient land-bridges in the colonization of the British Isles. A natural colonization of Ireland was deemed more likely than an ancient human-mediated introduction as has previously been proposed and potentially points to an increased mammalian fauna on the island in the early post-glacial period. Using genome-wide data has allowed us to tease apart broad-scale patterns of structure and diversity in a widespread carnivore in Europe that was not evident from using more limited marker sets and provides a foundation for next-generation phylogeographic studies in other non-model species.

evolutionary biology↗

bioRxiv2018

Untangling the Evolutionary History of European Bison (Bison bonasus)

European bison (Bison bonasus) are the largest endemic vertebrates in Europe, and one of the few megafaunal species to have survived the mass megafaunal extinction during the Pleistocene/Holocene transition (12-9 thousand years ago). Untangling their evolutionary history would provide valuable information about the response of European megafauna to periods of rapid environmental change. However, a severe and recent population bottleneck obscures much of the population history that could be inferred from the genomes of modern individuals. While several studies have attempted to analyse ancient European bison populations directly using ancient DNA, their datasets were limited in temporal and geographic range. In this study we present the most comprehensive dataset of ancient European bison mitochondrial genomes to date, with 131 ancient bison samples from across the Eurasian continent covering over 50 thousand years. We reveal patterns of bison distribution and concurrent environmental changes across a broad geographical and temporal range. In particular, population expansions following periods of extensive forest reduction combined with a decrease in anthropogenic pressures suggest that European bison remain preferentially adapted to an open steppe environment through to the present day.

evolutionary biology↗