David McClay

After fertilization cells of the embryo establish gene regulatory networks that progressively specify identities of all the cells of the organism. As this process proceeds the cells reach gastrulation where they engage in morphogenetic movements that constructs the primitive body plan. At a systems level the challenge in our lab is to understand specification of sea urchin embryos, a relatively simple model system that allows us to analyze the transcriptional control of morphogenesis. To date the gene regulatory networks we study are dynamic and composed of more than 100 transcription factors and a number of signal transductions that reflect a dynamic series of changes as cells diversify. The goal is to understand an epithelial-mesenchyme transition, homing of the primordial germ cells to their target tissue, invagination of the archenteron, movement of pigment cells, and formation of the skeleton. In each case an upstream gene regulatory network governs the downstream morphogenetic movement.