Meeting Abstract

33-2  Monday, Jan. 4 13:45  Role of the Rho/Rock pathway in sponge morphogenesis HILL, A*; SCHENKELAARS, Q; HALL, C; QUINTERO, O; FIERRO-CONSTAIN, L; RENARD, E; BORCHIELLINI, C; University of Richmond, Virginia; Aix-Marseille University, Marseille, France; University of Richmond, Virginia; University of Richmond, Virginia; Aix-Marseille University, Marseille, France; Aix-Marseille University, Marseille, France; Aix-Marseille University, Marseille, France ahill2@richmond.edu http://biology.richmond.edu/research/research-labs/april-hill-lab.html

The Rho associated protein kinase (ROCK) plays crucial roles in development across bilaterians including initiation of epithelial morphogenesis and regulation of cell shape and movement through action on the cytoskeleton. The Rho/Rock pathway is regulated, in part, by noncanonical Wnt signaling in complex animals. We studied the Rho/Rock pathway in the early branching freshwater sponge, Ephydatia muelleri. We demonstrated that Ephydatia ROCK protein exhibits Rho-kinase specific activity and is inhibited by two different commercially available inhibitors. We found that inhibition of ROCK activity prevented establishment of a functional aquiferous system (i.e., oscula and canals did not develop) and resulted in sponges forming unique outgrowths in the basal pinacoderm layer. We also found that cyclin D and DNA methyltransferase I were over-expressed during outgrowth formation while key genes in the Wnt pathway were moderately down-regulated. These data imply that Rho/Rock signaling may have conserved roles in morphogenesis across animal evolution.