The homeobox gene goosecoid is present in all vertebrate species. In the mouse it is first transiently expressed during gastrulation in the primitive streak and from E10.5 to E14.5 in the branchial arches, frontonasal mass and limb buds. In Xenopus embryos goosecoid mRNA injection has demonstrated a role in the Organizer phenomenon. However, homozygotic goosecoid mutant mice have a phenotype which is only related to its late phase of expression.
Southern blotting analysis has indicated the existence of additional goosecoid-related genes which might compensate for the absence of a phenotype at the gastrula stage. My research project will be focused on the identification of these additional mouse genes and to functionally analyze them through a genetic approach. Null mutant mice will be created and their phenotype will be histologically and molecularly characterized. In addition, misexpression of the new genes in transgenic mice will be analyzed.