Meeting Abstract

99.1  Thursday, Jan. 7  Evolution of Gene Regulatory Networks: Pax/Six in Ephydatia muelleri (Porifera; Demospongiae) RIVERA, Ajna*; CIENIEWICZ , Brandon; DANKA, Elizabeth; WINTERS, Ian; RUED, Anna; WARNER, Lisa; GENTILE, Lisa; HILL, Malcolm; HILL, April; University of Richmond; University of Richmond; University of Richmond; University of Richmond; University of Richmond; University of Richmond; University of Richmond; University of Richmond; University of Richmond arivera2@richmond.edu

The evolution of complexity from simpler forms has lead to much of the organismal diversity that we find astounding in nature. Modern genomics, phylogenetics and developmental biology techniques now allow us to dissect possible evolutionary routes from the simple to the complex. One promising way to do this is to study the evolution of gene-regulatory networks and their developmental functions. For example, many animals use the Pax/Six/Eya/Dac (PSED) network to specify eyes and other sensory organs. Complex interactions between multiple members of these four gene families, integration of other gene-families into the network, and absence of specific PSED interactions from several developmental contexts make the evolutionary history of this network extremely difficult to trace. To begin to understand this evolutionary history, we examine PSED members in simple animal, the sponge Ephydatia muelleri (Demospongiae). While sponges (phylum Porifera) lack sensory organs in the traditional sense, they do have at least two components of the PSED network: Pax and Six. Here, we show developmental expression, gene-knockdown, and chromatin-binding data in an attempt to understand the origins of a ubiquitous metazoan gene-regulatory network.