Violeta Lyubomirova Zhelyazkova‡, Nicola Fischer§|, Sebastien J Puechmaille¶§Corresponding author: Violeta Zhelyazkova ( violet_jl@abv.bg ) Corresponding author: Sebastien Puechmaille ( sebastien.puechmaille@umontpellier.fr ) © Violeta Zhelyazkova, Nicola Fischer, Sebastien Puechmaille. This is an open access preprint distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation:
Zhelyazkova VL, Fischer N, Puechmaille SJ (2023) Genetic diversity and population structure of the fungus Pseudogymnoascus destructans, the causative agent of whitenose disease: From large scale differentiation to locally homogeneous populations and genetically diverse infections in bats. ARPHA Preprints. https://doi.org/10.3897/arphapreprints.e109901 |  |
White-nose disease (WND), caused by the psychrophilic fungus Pseudogymnoascus destructans, represents one of the greatest threats for North-American hibernating bats. Research on molecular data has significantly advanced our knowledge on various aspects of the disease, yet more studies are needed regarding patterns of P. destructans genetic diversity distribution. In the present study, we investigate three sites within the native range of the fungus in detail: two natural hibernacula (karst caves) in Bulgaria, South-Eastern Europe, and one artificial hibernaculum (disused cellar) in Germany, Northern Europe, that we intensively surveyed between 2014 and 2019. Using 18 microsatellite and two mating type markers, we describe how P. destructans genetic diversity is distributed between and within sites, the latter including differentiation across years and seasons of sampling; across sampling locations within the site; and between bats and hibernaculum walls. We found significant genetic differentiation between hibernacula, but we could not detect any significant differentiation within hibernacula based on the variables examined, which indicates that most of the pathogen’s movement happens within sites. Genotypic richness of P. destructans varied between sites within the same order of magnitude, being approximately two times higher in the natural caves (Bulgaria) in comparison to the disused cellar (Germany). Within all sites, the pathogen’s genotypic richness was higher in samples collected from hibernaculum walls than in samples collected from bats, which corresponds with the hypothesis that hibernacula walls represent the environmental reservoir of the fungus. Multiple pathogen genotypes were commonly isolated from a single bat (i.e., from the same swab sample) in all study sites, which might be an important feature to take into consideration when studying disease progression.