Date of Graduation

Spring 2018

Document Type

Honors Research Project

Degree Name

Bachelor of Science

Major

Biology

Research Sponsor

Dr. Hazel Barton

First Reader

Dr. Leah Shriver

Second Reader

Dr. John Senko

Abstract

White-nose Syndrome (WNS) is an emergent epidemic disease of bats in North America. Caused by the novel fungal pathogen Pseudogymnoascus destructans, with a mortality rate of >75%, in the last decade WNS has led to the local extinction of numerous bat species. Despite this high mortality, one species, the Virginia big-eared bat (Corynorhinus townsendii virginianus) remains unaffected. Virginia big-eared bats (VBEs) are commonly found covered in a yellow, oily substance, with a pelage commensal population dominated by the yeast, Debaryomyces udenii. As D. udenii is an oleaginous yeast that produces yellow colonies, the fungus may be responsible for the production of this oily substance on bats. In order to test this, 54 swab samples from the pelage of various bat species, including VBEs, were collected, along with cultures of D. udenii and the control yeast Saccharomyces cerevisiae. These samples were extracted using the Bligh and Dyer lipid extraction method and reversed-phase lipid chromatography to identify shared lipid metabolites. The data demonstrated that only a handful of lipids were unique to D. udenii (compared to S. cerevisae), and only seven of these lipid candidates were found on VBE pelage extracts. Instead of indicating that D. udenii was responsible for the production of the yellow material, our data suggests that the yellow material on bats is selecting for the presence of this yeast, possibly over filamentous fungi. VBEs have large pararhinal glands, our hypothesis is that the material produced by these glands might be anti-fungal, selecting against the growth of filamentous fungi.

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