LE3 .A278 2020

2020

Easy, Russell
Smith, Todd

Acadia University

Bachelor of Science

Honours

Biology

Biology

Small proteins called antimicrobial peptides (AMPs), secreted onto the skin of frogs, allow them to resist infection by many pathogens. The objective of this research was to determine how stress, specifically temperature, alters AMP production in green frogs (Rana clamitans), the most abundant frog species in Nova Scotia, Canada. A total of 18 frogs were divided equally into three cohorts and subjected to different temperature conditions: 4 C, which is typical of hibernation, 22C, which is typical of summer temperatures and served as a control, and 26 C, which is at the higher end of the thermal range of green frogs. Epidermal mucus swabs were taken directly after the course of each experimental trial. SDS-PAGE and mass spectrometry were then performed to separate and identify AMPs and other proteins of interest that were present in the epidermal mucus. Molecular analysis was also performed, which included designing and optimizing primer sets for genes encoding antimicrobial peptides, as well as barcoding genes, which can be used in future studies. Our results showed that frogs in the control and warming cohorts had similar epidermal proteomic profiles, with the greatest number of protein bands appearing in the protein profiles of frogs in the warming cohort. Frogs in the cooling cohort had a highly depressed epidermal mucus proteome and did not display any strong visible bands. Mass spectrometry confirmed the presence of a number of proteins of interest in the control cohort samples; however, AMPs were not identified. The results of this research may contribute to understanding how temperature affects the expression of genes encoding AMPs and other immunological proteins, which is of particular interest given recent global climate change and mass declines of amphibian populations.

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https://scholar.acadiau.ca/islandora/object/theses:3360