Characterization of Complementary DNA Encoding the Precursor for Gonadotropin-Releasing Hormone and Its Associated Peptide from a Teleost Fish

Reproductive maturity among male African cichlids Haplochromis burtoni is cued by a series of environmental and social interactions and is mediated physiologically by GnRH. A cDNA clone encoding the precursor for GnRH was isolated from this teleost. The molecular architecture of the predicted prohormone is analogous to that of the previously characterized mammalian forms; however, the predicted sequence of the associated peptide is strikingly different. Attempts to isolate a putative second precursor using low stringency hybridization were not successful despite evidence that a second related decapeptide exists in at least some teleost species.