Cloning and sequence analysis of cDNA for corticotropin-releasing factor precursor from the teleost fish Catostomus commersoni.

The sequence of a cDNA encoding the corticotropin-releasing factor precursor has been identified by screening lambda gt11 libraries constructed from poly(A)+ RNA of the hypothalamic region of the white sucker Catostomus commersoni brain with synthetic oligonucleotide probes deduced from the sequence of the rat corticotropin-releasing factor. The amino acid sequence of corticotropin-releasing factor of the sucker is strikingly conserved when compared to its counterpart from rat and differs only in two positions at the carboxyl terminus; in contrast, there is little similarity between their cryptic regions.