Meeting Abstract

16.2  Monday, Jan. 4  Cell Adhesion and the Cell Biology of Gastrulation in the cnidarian, Nematostella vectensis MAGIE, Craig R.*; DALY, Marymegan; MARTINDALE, Mark Q.; California State University, Fresno; Ohio State University; University of Hawai’i cmagie@csufresno.edu

Gastrulation is a central event in metazoan development and the first morphogenetic process in the embryo, resulting in the formation of a multilayered embryo from a monolayered blastula. Adhesive mechanisms, both cell-cell and cell-extracellular matrix, are intimately involved in this process. Modulation of adhesive complexes could therefore be seen as a central component in the molecular control of morphogenesis, the translation of information encoded within the genome into organismal form. Understanding how morphogenesisis controlled in early-branching metazoans will help clarify the evolution of morphogenetic mechanisms. To this end we have examined the cell biology underlying gastrulation in the cnidarian, Nematostella vectensis, a valuable context in which to study morphogenesis in an early-branching taxon. Gastrulation in Nematostella occurs through invagination. The cells adjacent to the blastopore adopt extreme bottle-like morphologies as they constrict their apical surfaces, but retain projections that extend to the archenteron as they zip up against the basal surface of the ectodermal cells. In silico screening of the Nematostella genome has revealed a number of cell junction components that may be involved in this process, as well as other genes potentially involved in cellular behaviors required for gastrulation. Discovery of the molecular nature of morphogenesis in early-branching groups such as cnidarians, coupled with comparisons across the metazoa, promises to reveal the ways evolution has generated the myriad forms seen in the animal kingdom.