Population Genomics and Mutational History of the Invasive, Epidemic Clone of Pseudogymnoascus Destructans, Causal Agent of White-nose Syndrome in Bats

Abstract

Since the 2006 detection of White-nose Syndrome (WNS) in New York,~6.7 million bats have died in North America. WNS is caused by the ascomycete fungus, Pseudogymnoascus destructans. Evidence points to a single introduction in North America from Europe. In Europe, pathogen populations are genetically diverse and sexually reproducing. Here, bats survive even when infected. While in North America mortality is high. Based on multi-locus sequence studies, the North American fungal population is clonal without evidence of recombination. I compared SNPs with whole-genome Illumina sequencing of 37 isolates from 2008 to 2015 which represented current range of epidemic in Canada and US. I asked two questions: First, does the pathogen population represent one clonal expansion? Second, in the course of this expansion, is recombination occurring? Genomic diversity consistent with mitotic recombination was detected among isolates from New Brunswick, Nova Scotia and Prince Edward Island. Our observation shows that the pathogen is evolving.