Meeting Abstract
The insulin and insulin-like signaling network (IIS) is a key molecular network (consisting of 70+ genes, circulating hormones, membrane-bound receptors, cellular signaling proteins) that integrates environmental signals with growth, reproduction, physiological stress, and aging. Previously we have demonstrated that the IIS network is rapidly evolving in amniotes (reptiles and mammals), particularly the interactions between the hormones (IGF1 and IGF2) and their receptors. Here we focus on the evolution of the IIS network within a species. We utilize a metapopulation of garter snakes (Thamnophis elegans ) that has diverged along life-history, physiological, and genetic axes into two ecotypes that correspond to two habitat types. At the level of life history strategies, individuals of these two ecotypes differ in their growth rates, reproductive rates, and lifespan. Thus we hypothesize they have also diverged in various aspects of their IIS network. We compile results from hormone assays of circulating IIS hormones, gene expression from quantitative PCR data across tissues and high throughput RNA sequencing, and gene sequence variation from sequence capture data, to evaluate variation in the IIS network within and among the life-history ecotypes. Because the IIS network is the main stress-response network, we further explore plasticity within this network in response to environmental variation. We discuss the results in an integrative format extending from the genetic networks, to the physiology, and the life-history traits of each ecotype within the context of their respective habitats and selection pressures.
