Date of Completion
2025
Document Type
Honors College Thesis
Department
Biology
Thesis Type
Honors College
First Advisor
Dr. Joaquin Nunez
Second Advisor
Dr. Brent Lockwood
Third Advisor
Dr. Eric Von Wettberg
Keywords
Genetic Variation, Drosophila melanogaster, Embryonic, Heat Shock Tolerance, Wolbachia, Inversions
Abstract
Temperature adaptations are determinants of the physiological limits of most species and are key to understanding how natural populations will adapt to climate change. Drosophila melanogaster is a classic model organism used to uncover the genetic basis of thermal responses. Yet, while much research has been conducted on the thermal physiology of adult flies, many gaps in knowledge remain regarding thermal adaptations at the embryonic stage, a fundamental phase in development. This research aims to uncover the factors underlying an embryo's capacity for thermal adaptation. To achieve this, the heat shock tolerance of twenty-four lines from the Drosophila Genomics Reference Panel (DGRP) was assessed at 35°C. At this temperature, the hatch rate for D. melanogaster embryos is expected to be around 50%. Our results show large amounts of phenotypic variation in thermal response at 35°C with survival ranging from 1.2% to 59% among lines. The data suggest that standing genetic variation plays a key role in thermal tolerance. We also observe a statistical association between this trait and genetic variation at the SP70 gene—previously implicated in thermal tolerance through work in the Nunez and Lockwood labs—and its interaction with Wolbachia, a gram-negative bacterial symbiont, as well as the inversion In(2L)t. Specifically, flies without Wolbachia and carrying the A/A allele exhibit improved heat shock survival compared to those with the C/C allele. However, DGRP lines infected with Wolbachia show a reversed phenotypic pattern.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
Recommended Citation
Bufferd, Eliza M., "Genetic Variation in Heat Tolerance within the Drosophila melanogaster Genetics Reference Panel (DGRP)" (2025). UVM Patrick Leahy Honors College Senior Theses. 690.
https://scholarworks.uvm.edu/hcoltheses/690