Pires, Samantha2023-01-112023-01-112023-01-11https://hdl.handle.net/1813/112724The buckeye butterfly, Junonia coenia, shows seasonal variation in wing coloration. The duplicate genes treh-1a and treh-1b encoding a soluble form of trehalase are implicated in this environmentally induced phenotypic variation. treh-1a has been shown to be involved in the mechanism of ommochrome pigmentation plasticity in J. coenia but the role of treh-1b is unknown. In this study, I first aimed to characterize the role of treh-1b, a presumptive metabolic pathway enzyme, in both ommochrome pigmentation, and, second, to assess the potential adaptive role of trehalase upregulation in cold tolerance. CRISPR mutagenesis of the treh-1b promoter, as well as the coding region, revealed various developmental phenotypes, but had no obvious effect on ommochrome pigmentation. I next used chill coma recovery time bioassays to ask how treh-1a -associated phenotypes affect cold tolerance. My bioassays revealed that Red line butterflies (red phenotype treh-1a allele) recover from cold-shock faster than Nijh line butterflies (tan phenotype treh-1a allele) when both groups come from a warm environment, but not when both groups come from a dark, cooler environment. Interestingly, both Nijh and Red butterflies show a large reduction in recovery times when coming from a dark, cooler environment. This suggests that Red butterflies may have increased thermal retention compared to Nijh butterflies, thus allowing them to recover from cold-shock faster than Nijh butterflies. This also suggests acclimation to cooler, darker conditions impacts J. coenia recovery after cold-shock.en-USdissertation or thesis