Meeting Abstract
Organisms are not static over their lifetimes. Characteristic change as the genome unfolds across ontogeny. This change can be extreme, especially over the course of complex life cycles that include abrupt changes in physiology, behavior, and morphology. Larvae and adults of insect species that undergo complete metamorphosis are often subject to distinct environmental conditions, presumably applying selection pressures for highly variable environmental responses, or environmental sensitivity, across development. This begs the question: Is performance under a given set of environmental conditions constrained across metamorphosis or is there the potential for adaptive decoupling in distinct life stages? To answer this question, genetic correlations in lower thermal limits across metamorphosis was estimated for approximately 200 isogenic Drosophila melanogaster DGRP lines. Survival curves spanning LD50 and LD90 were estimated for a subset of lines, while survival at -5C for one hour was measured on all lines, proving a reliable proxy for various summaries of survival curves. Next, genetic correlations were determined in larvae vs. adults from each line. Preliminary results show low genetic correlations, suggesting distinct genetic architecture for thermal stress across development. We also discuss the results of genome-wide association analysis (GWAS) to begin to distinguish mechanisms by which thermal tolerance may be ontogenetically decoupled.
