Meeting Abstract

116.8  Monday, Jan. 7  The freshwater sponge, Ephydatia muelleri, as a model to study the evolution of developmental regulatory programs HILL, A.*; RIVERA, A.; WINTERS, I.; RUED, A.; DING, S.; POSFAI, D.; GENTILE, L.; WEBB, E.; TROK, W.; Univ. of Richmond, Richmond, VA; Univ. of the Pacific, Stockton, CA; Stanford Univ. School of Medicine, Stanford, CA; Univ. of Pittsburgh Medical Center, Pittsburgh, PA; Univ. of Oxford, Oxford, England; Univ. of Richmond, Richmond, VA; Univ. of Richmond, Richmond, VA; Univ. of the Pacific, Stockton, CA; Univ. of the Pacific, Stockton, CA ahill2@richmond.edu

Sponges possess an extensive repertoire of animal specific transcription factor, signal transduction and structural genes that first appeared at the dawn of animal multicellularity and continued to expand and diversify as the animals evolved ever increasing levels of complexity. We are using the emerging freshwater sponge model, Ephydatia muelleri, to study the evolutionary origins and functions of developmentally important gene families and networks. Through the development of methodologies (e.g., RNAi and expression vectors) as well as directed studies on specific genetic pathways, our lab is contributing to the growing body of knowledge and resources for this model organism. For example, expression studies as well as gene knockdown experiments demonstrate a role for Pax and Six genes in the endothelial lining of the canal system and the development of the choanoderm in these freshwater sponges. Current work is exploring the regulatory relationships and downstream targets of a putative Pax-Six (PS) component of the evolutionarily conserved Pax/Six/Eya/Dac (PSED) gene regulatory network.