Cloning, tissue distribution and nutritional regulation of a fatty acyl Elovl4-like elongase in mud crab, Scylla paramamosain (Estampador, 1949)

In this report, the full-length cDNA of fatty acyl Elovl4-like elongase was cloned from the hepatopancreas of Scylla paramamosain by rapid-amplification of cDNA ends (RACE). To the best of our knowledge, this is the first report of Elovl4-like elongase in crustaceans. The full-length cDNA of Elovl4-like was 1119 bp, which included a 5′-terminal untranslated region (UTR) of 58 bp, a 3′-terminal UTR of 44 bp and an open reading frame (ORF) of 1017 bp encoding a polypeptide of 338 amino acids. Tissue distribution analysis revealed that Elovl4-like transcripts are widely distributed in various organs, with high mRNA levels in the hepatopancreas and cranial ganglia. Further, Elovl4-like transcriptional levels in hepatopancreas were up-regulated in proportion to the replacement of dietary fish oil (FO) with soybean oil (SO). The result showed that Elovl4-like transcripts increased about 0.83 and 1.12-fold respectively when SO constituted 80% and 100% of total oil (P < 0.05). These results may contribute to better understanding of the long-chain polyunsaturated fatty acids (LC-PUFA) biosynthetic pathway and regulation mechanism in this species.