Origin and Diversification of Gene-by-Environment Interactions

An organism’s phenotype is determined through a combination of genetic and environmental factors. These factors can operate independently, although environmental factors often modulate the expression of genetic factors in a predictable way. The interplay between environmental cues and gene expression can be described as a gene-by-environment (GxE) interaction. Significant effort has been spent working to characterize GxE interactions in human, lab, and agricultural systems because these interactions determine the spectrum of variation in responses to disease, ecological conditions, and other phenomena of broad interest. We therefore have a good understanding of the kinds of physiological processes and gene networks involved in detecting, transducing, and responding to environmental cues in a handful of systems. What we know less about, however, is how GxE mechanisms originate and diversify across species. How does a trait first become genetically responsive to an environmental cue? And, then, how do GxE interactions change over time in different populations or species to adapt to different types of predictable external cues? The goal of our research program is to characterize the molecular basis of variation in GxE interactions within and between species. We use an insect model clade, butterflies, which shows substantial geographic variation in GxE seasonal color pattern phenotypes. Our current focus is on characterizing tissue- and stage-specific gene regulatory networks activated by the steroid hormone 20-hydroxyecdysone, which transduces seasonal environmental cues to target tissues. To complement this work, we use genetic mapping and manipulations to characterize specific genes and regulatory elements involved in regional variation of seasonal phenotypes within and between closely related species. Ultimately, this research will identify developmental genetic mechanisms that allow hormone-mediated GxE interactions to diversify and adapt in nature. Project Number: 1R35GM161748-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: Robert Reed | Institution: CORNELL UNIVERSITY, ITHACA, NY | Award Amount: $423,195 | Activity Code: R35 | Study Section: Special Emphasis Panel[ZRG1 MGG-D (55)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11260764