Date of Graduation

Summer 2019

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Thomas Tomasi

Keywords

immune system, hibernation, torpor, WNS, white-nose syndrome, inflammation, Eptesicus fuscus, Pseudogymnoascus destructans, Pd

Subject Categories

Biology | Immunology of Infectious Disease | Other Immunology and Infectious Disease | Physiology | Zoology

Abstract

White-nose syndrome (WNS) has had a large negative impact on bat populations across eastern North America since its arrival in 2006. Bats affected by WNS appear to die of starvation, possibly due to the increased arousals during hibernation when there is no food present to replace the energy used to arouse. During hibernation, the bat’s immune system should be suppressed. However, once a bat of a susceptible species is exposed to the fungus that causes WNS, Psuedogymnoascus destructans (Pd), the immune system seems to respond, potentially causing an elevation in metabolic rate, which may cause the bat to arouse more often. I hypothesize that resistant bats do not mount an immune response; however, if they do mount an immune response, I hypothesize that bats inoculated with Pd and treated with an anti-inflammatory treatment will not respond to the infection, ultimately preserving fat reserves and lowering metabolic expenditures during hibernation. I tested these hypotheses by inoculating a species that does not suffer from high WNS mortality (big brown bats: Eptesicus fuscus), with Pd. Meloxicam was given to one of the three treatment groups in order to suppress the immune system. Metabolic rate during torpor, via oxygen consumption, was measured in addition to arousal/torpor bout patterns, the latter utilizing temperature-sensitive dataloggers. To quantify expression of four immune-function genes (NLRP10, CD200, ICAM5, and TNFRSF21), gene activity was measured via RT-qPCR on tissue and blood samples taken from each bat pre- and post- hibernation. These genes were chosen based on a prior study that showed differences in these genes between susceptible and resistant species. There were no significant differences found across treatment groups for gene expression, nor energetic data; however, hibernation did suppress NLRP10 expression, and blood samples consistently had higher gene expression than tissue samples, thus indicating these genes may be expressed at low levels in some tissues.It is imperative that we continue investigating the differences between susceptible and resistant bat species as WNS is advancing westward throughout the country.

Copyright

© Keslie Skye Naffa

Open Access

Share

COinS