Meeting Abstract
P1.121 Friday, Jan. 4 Rho GTPase function during early development in the cnidarian, Nematostella vectensis KHALILI, S.; WHALEN, W.; MAGIE, C.R.*; California State University, Fresno; California State University, Fresno; Quinnipiac University craig.magie@quinnipiac.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. Gastrulation strategies involve many different cellular behaviors that require the precise control of cell dynamics, making gastrulation an excellent context in which to study the molecular mechanisms underlying morphogenesis. In addition, understanding how morphogenesis is controlled in early-branching metazoans will help clarify the evolution of these processes. To this end we have examined the expression and function of the Rho family of small GTPases (including Rho, Rac, and Cdc42) during gastrulation in the cnidarian, Nematostella vectensis. Rho GTPases have been shown to be important regulators of cellular behavior through their effects on a variety of processes, including actin cytoskeletal rearrangement, transcriptional activation, and regulation of cell adhesion. One of the pathways through which Rho is thought to act is downstream of the Wnt/planar cell polarity (PCP) pathway. In Nematostella, morpholino oligonucleotides that block function of the PCP cell surface molecule Strabismus also block invagination. Because of this, we hypothesize that Rho GTPases may be involved in the regulation of invagination during gastrulation in Nematostella. We are currently utilizing a morpholino-based approach to perturb function of Rho, as well as a pharmacological approach to inhibit the function of downstream Rho effectors. We have observed that Rho, Rac and Cdc42 are ubiquitously expressed at the gastrula stage in Nematostella, with a higher level of expression in the endoderm at the planula stage. Preliminary functional data suggest that the molecular mechanisms underlying Rho function in Nematostella may be distinct from those in bilaterian taxa.
