High Diversity and Low Genetic Differentiation Among Geographic Populations of Myotis yumanensis in Western Canada

TL;DR

This study examines the genetic diversity and population structure of Yuma Myotis bats in Western Canada to better manage their vulnerability to white-nose syndrome.

Contribution

The study provides the first detailed genetic analysis of Myotis yumanensis populations in Western Canada, revealing high diversity and low differentiation.

Findings

High genetic diversity was found within most geographic populations of Myotis yumanensis.

Low genetic differentiation was observed among populations, despite geographic differences.

The Lillooet population showed the highest genetic differentiation, suggesting non-geographic factors influence gene flow.

Abstract

Bats are keystone species and play important roles in natural ecosystems. There are at least 18 bat species in Canada, and the highest species diversity is found in British Columbia in Western Canada. At present, bats in 9 of the 10 Canadian provinces (except British Columbia) and 40 of the 48 continuous continental states in the United States of America have been reported to suffer from white-nose syndrome, a deadly infection caused by the fungus Pseudogymnoascus destructans. Yuma Myotis (Myotis yumanensis) is a common bat species in Western Canada that contributes significantly to insect pest control but is susceptible to white-nose syndrome. However, there is so far very limited genetic knowledge about this bat, including its population structure, especially in Western Canada. By analyzing 336 M. yumanensis from 10 geographic locations in Western Canada using nine nuclear microsatellite loci, this study revealed high genetic diversity within most geographic populations and low genetic differentiation among geographic populations. Specifically, differences in the levels of genetic differentiation between interior and coastal populations were observed. Our results on population structure and potential gene flow among different areas will be helpful for the management of white-nose syndrome.

Myotis yumanensis is a small insectivorous bat distributed in Western North America and is susceptible to white-nose syndrome, a devastating fungal disease. Effective management of the disease in M. yumanensis requires an understanding of its population structure to identify possible routes and barriers of disease transmission. Here we used nine microsatellite loci to investigate genetic variation among 336 M. yumanensis from 10 locations in Western Canada. Our analyses revealed high genetic diversity and low but statistically significant genetic differentiation among several geographic populations. Interestingly, though geographically it was not the most distant, the Lillooet population showed the highest genetic differentiation from others, suggesting factors other than geographic distance also contributed to gene flow in this species. While white-nose syndrome has been reported in M. yumanensis populations in neighbouring Washington State in the United States of America, as of 2023, the causative pathogen was not detected on the wings of our analyzed 336 M. yumanensis bats in Western Canada. However, continuing monitoring is required to provide the most updated information about the white-nose syndrome status in these populations. The knowledge of M. yumanensis population structure in Western Canada will help develop effective management strategies for protecting this bat species from white-nose syndrome.

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