FUNCTIONAL AND MOLECULAR ASPECTS OF THE GONADOTROPIN RELEASING HORMONES IN THE AFRICAN CATFISH, CLARIAS GARIEPINUS

摘要

Two molecular forms of GnRH were identified in the African catfish, Clarias gariepinus: catfish gonadotropin-releasing hormone (cfGnRH) and chicken gonadotropin-releasing hormone (cGnRH-II). They differ in gonadotropine hormone (GTH)-release activity. cGnRH-II being about a hundred rimes as potent as cfGnRH. This difference correspends to different GnRH receptor binding affinities. cDNAs encoding both GnRH pre-prohormones were cloned and specific antibodies were raised against the GnRHs. By immunocytochemistry and In situ hybridization cGnRH-II Tvas localized in the midbrain tegmentum, cfGnRH in the rostro-ventral forebrain.