Meeting Abstract
The phenomenon of phenotypic plasticity, common in insects, occurs when one genotype can generate different phenotypes in response to environmental changes. Genetic accommodation occurs when these environmentally induced phenotypes are selected on over multiple generations and lose their dependence on or become hypersensitive to the initial environmental cues. While the process of genetic accommodation has been demonstrated through artificial selection experiments, the genetic basis underlying this process remains unclear. Previous studies have shown that polyphenisms might evolve through genetic accommodation. In this project, a normally black mutant M. sexta strain was subjected to heatshock and the resulting epidermal color change was observed. A polyphenic strain and a monophenic strain were evolved through selection for either green or black epidermal color under heat-shock conditions.The expression of hormonal biosynthesis and response genes, specifically in the ecdysteroid and juvenile hormone (JH) signaling pathways, were analyzed in heat shocked and non-heat shocked selected animals and compared to the effects of heat shock on unselected control animals. Our initial findings suggest that JH signaling played a critical role from the onset of selection and mediated the heat-shock response. These studies will begin to help us better understand the process of genetic accommodation at the molecular level and ultimately allow us to determine whether genetic accommodation occurs in nature.
