Cloning, tissue distribution and nutritional regulation of a Delta 6-desaturase-like enzyme in rainbow trout

This report describes the cloning, nutritional regulation and tissue distri bution of a desaturase-like enzyme in rainbow trout (Oncorhynchus mykiss). The open reading frame of the trout desaturase-like cDNA encodes a 454-amin o acid peptide that contains two membrane-spanning domains, three histidine -rich regions and a cytochrome b(5) domain, which all align perfectly with the same domains located in other recently identified vertebrate Delta5- an d Delta6-desaturases. Nutritional regulation of trout desaturase-like gene expression, as well as the tissue expression profile, are also similar to t hose observed in other vertebrate Delta5- and Delta6-desaturases. Finally, the sequence alignments between the predicted protein sequence of rainbow t rout desaturase-like and other Delta6- and Delta5-desaturases revealed a hi gh percentage identity with Delta6-desaturases (64-66% identity with verteb rate Delta6-desaturases). These results demonstrate for the first time the presence and nutritional modulation of a Delta6-desaturase-like cDNA in rai nbow trout. (C) 2001 Elsevier Science Inc. All rights reserved.