Meeting Abstract

11.1  Thursday, Jan. 3  Insight from Lamprey Genomics: Brain and Pituitary Reproductive Hormones in Lampreys SOWER, STACIA A.*; KAVANAUGH, SCOTT I.; FREAMAT, MIHAEL; University of New Hampshire, Durham; University of New Hampshire Durham; University of New Hampshire, Durham sasower@cisunix.unh.edu

The sea lamprey has become a model system for analysis of the evolution of many genes and systems including the evolution of the neuroendocrine regulation of reproduction (Sower 2003). Lampreys as basal vertebrates were identified in a key pivotal position such that the mapping of the lamprey genome started in Jan 2005. Lampreys are the earliest evolved vertebrates for which there are demonstrated functional roles for two GnRHs that act via the hypothalamic-pituitary-gonadal axis controlling reproductive processes. From our many structural and functional studies, we have determined the primary amino acid and cDNA sequences of two forms of GnRH, lamprey GnRH-I and -III, the cDNAs of one GnRH receptor, GTH-like beta, and one glycoprotein (GTH-like) receptor. With availability of the lamprey genome, we have identified a novel GnRH form, a putative second GnRH receptor and a thyroid stimulating hormone receptor. The high conservation of these hormones and their receptor throughout vertebrate species makes the lamprey model highly appropriate for examining the neuroendocrine system. The lamprey genome offers a model system in which novel receptors can be identified using gene prediction models from their sequence and their percent identity. Supported by NSF Grant # 0421923 to SAS.