Conserved expression of a novel gene during gonadal development

We isolated the novel gene Gonad Expressed Transcript (GET) from a chicken embryonic gonad library enriched for differentially expressed male transcripts. Chicken GET encodes a predicted protein containing a Pfam-B 30624 domain with homology to a putative orthologue in mammals. Chicken GET expression was confined to the developing urogenital system. It was first detected in the glomerulus of the mesonephros of both sexes from embryonic day (E) 2.5. At E4.5, expression switches to the gonad of both sexes and then localizes to the gonadal cortex. We isolated the putative mouse orthologue and examined expression in the mouse embryo. Gonadal expression was conserved. Ovarian expression localized to the cortex as in the chicks. However, in contrast to the chicken, testis expression localized to the cords. In the adult, GET is expressed in the ovary but not the testis of both the chicken and the mouse. Expression of GET in the müllerian duct, wolffian duct, metanephric kidney, and external genitalia, suggests that GET may play a wider role in the development of the urogenital system.