Molecular cloning of a novel putative G‐protein coupled receptor expressed during rat spermiogenesis

A cDNA clone encoding a novel putative G-protein coupled receptor has been isolated from a rat testis cDNA library using a PCR-amplified cDNA fragment as a hybridization probe. Northern blot analysis reveals that a corresponding 1.5 kb mRNA is exclusively expressed in testis. By in situ hybridization experiments this mRNA has been localized in spermatocytes and spermatids but not in spermatogonia, Leydig or sertoli cells. Ontogenic studies show that expression of the receptor-encoding mRNA and sexual maturation are correlated reaching highest levels during the second and third months. Although the ligand for this receptor has not yet been identified, this receptor may play a role during reproduction.