[Cloning of the cDNA, while encoding a hypothalamic neuropeptide in the rat, related to the melanin-concentrating hormone in the salmon].

In order to identify the neuropeptide related to salmon melanin-concentrating hormone (MCH) synthetized by neurons of the posterior hypothalamus in the mammals, we have screened rat hypothalamus and rat brain cDNA expression libraries using MCH antiserum. Five recombinants were isolated, which cDNAs were amplified using the polymerase chain reaction. One of them hybridized to RNAs exclusively located in hypothalamic neurons stained by the same antiserum, as seen by performing in situ hybridization and immunocytochemical techniques on the same section. The sequence analysis showed that this cDNA corresponds to the end of the open reading frame encoding a MCH-like peptide and to the 3' untranslated region. The rat MCH is very similar to salmon MCH (greater than 85% homologies in the 14C-terminal residues).