CAREER: Determining the role of regulatory evolution in developmental divergence using a marine model

Development is a fundamentally conserved and constrained process, but major changes in development mode have evolved, even across closely related species and short evolutionary time scales. This research investigates the genomic differences that shape developmental evolution by using closely related marine annelid species that exhibit different development modes. The project combines comparative genomics, gene expression, and hybridization assays to uncover the relationship between evolutionary divergence and development. This approach will inform our understanding of how speciation and developmental differentiation begin at the molecular level. The research is integrated with an education program designed to expand retention of undergraduate students in STEM fields as well as enhance access to early research and mentoring experiences. The education goals include establishing new faculty/student and peer-mentoring opportunities to increase participation of students in evolution, genetics, and developmental fields and providing new opportunities for research in coastal habitats. Finding the genetic basis of developmental change is a critical component of understanding diversification and evolution. This project identifies the regulatory differences that create phenotypic change during development using a unique set of species, including the emerging developmental model Streblospio benedicti. This marine annelid produces two distinct offspring types that differ in egg size, embryogenesis, and larval life-history within a single species. By identifying genes that are expressed differently based on life-history mode, within and across species, gene expression changes will be linked to developmental consequences. This comparative framework will reveal both the general rules of developmental evolution, and the specific genes involved in life-history switches. The research approach allows for separation of genetic differences that are species-specific from ones that are functionally associated with changes in embryology and life-history. Dissecting gene regulatory evolution at such a fine evolutionary scale will lead to a detailed understanding of how development evolves. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.