Meeting Abstract
We use the sea urchin as a model system to explore the evolution of developmental mechanisms, particularly with regard to the larval skeleton. Skeletogenic cells ingress into the blastocoel and form two ventrolateral clusters in response to cues from the overlying ectoderm. These cells then secrete a variety of proteins, which leads to the formation of a pair of triradiate spicules on either side of the archenteron. Recently, we have been focused on the molecular basis of differences in skeletogenesis between derived species and the “primitive” pencil urchin, Eucidaris tribuloides. We have been working to characterize the expression of genes that regulate the epithelial-mesenchymal transition associated with ingression as a first step in gaining insight into a heterochronic shift that has occurred during sea urchin evolution. We also have preliminary data for the effects of changes in factors such as pH, salinity, and temperature on embryogenesis as we begin to compare the pencil urchin with progressively more derived species for insight into differences in the plasticity of their response to changes in the environment. All of our work at the critical intersection of ecology, evolution, and development is conducted by undergraduate students in the context of a small liberal arts institution.
