Mild Heat Stress Reduces Developmental Viability in Temperature-Insensitive TrpA1-Knockout Drosophila melanogaster

Anh Ly, Nfn Aysha, Nicole Rodriguez
Department of Biology, Rutgers University, Camden NJ 08102

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Abstract

Climate change has substantially increased the frequency and intensity of heat waves, leading to heightened temperatures worldwide. This escalation poses a significant threat to insects because they rely on external factors such as sunlight or shade to regulate their internal body temperatures. Insects play a crucial role in our ecosystem such as decomposing organic matter, pollinating crops, maintaining healthy soil, and controlling pests. Maximizing conservation efforts might not be possible without understanding how these organisms respond to heat stress. In this study, Drosophila melanogaster was used as a model for insects, an ectothermic species. We conducted thermal and developmental assays to examine the impact of heat stress on the reproductive and developmental success of D. melanogaster. After 24 hours of mating at a 2:1 female-to-male ratio under control (20°C) and mild heat stress (30°C) conditions, D. melanogaster eggs were collected. Subsequent development of these eggs into pupae and adults was recorded as percentages to measure developmental success. Our results showed a severe reduction in developmental viability in both Wild-type and TrpA1-Knockout genotypes under heat stress. Interestingly, we found that pupae were more susceptible to heat stress than larvae. Due to the low power, we did not see any significant effects of temperature on D. melanogaster’s oviposition rates, or the average number of eggs produced. However, there is a trend that increasing temperatures affect the oviposition rates in wild-type (temperature-sensitive) D. melanogaster but not TrpA1 mutants (temperature-insensitive). Nevertheless, this study provides a framework for understanding the reproductive and developmental responses of Drosophila melanogaster to heat stress.