Meeting Abstract

66.3  Wednesday, Jan. 6  Identification and expression of genes for sex determination in the starlet sea anemone, Nematostella vectensis TRAYLOR-KNOWLES, N.*; REITZEL, A.M.; FINNERTY, J. R. ; Boston University; Woods Hole Oceanographic Institute; Boston University ntk17@Bu.edu

Sex determination in some animals is patterned by differential expression of transcription factors from the two gene families, DM-domain family and the Sox family. Throughout bilaterians the DM-domain genes, including doublesex in Drosophila melanogaster, Mab-3 from Caenorhabditis elegans and DMRT in vertebrates, are primarily involved in differentiation of male-specific characters. Sry, a member of the Sox family, is a critical gene for male specification in mammals. Genetic mechanisms for sex determination in early diverging animals (e.g., cnidarians, sponges) are unknown. Elucidating these molecular pathways will provide the necessary information for ascertaining conserved aspects of sex determination throughout animals and when these mechanisms likely evolved. Previously, a single DM domain containing gene was found in Acropora millepora, but the role of these transcripts in sex determination could not be elucidated due to the hermaphroditic nature of this coral.We have utilized the emerging model cnidarian Nematostella vectensis to identify and study expression of candidate genes involved in sex determination. Through a combination of similarity searches of the Nematostella genome and phylogenetic methods, we identified 6 distinct DM domain containing genes and one Sry-like gene. We characterized differential expression patterns of Nematostella DM-containing and the Sry-like genes using quantitative PCR and in situ hybridization. Our results show that due to the separate sex nature of Nematostella and the presence of these genes, this cnidarian will serve as a valuable model in understanding the evolution of sex determination.