title: Molecular cloning, mRNA expression and nutritional regulation of a Δ6 fatty acyl desaturase-like gene of mud crab, Scylla paramamosain.
abstract: Fatty acyl desaturases (Fads) are critical enzymes in the pathways for the biosynthesis of the highly unsaturated fatty acids (HUFA). Here we report on the molecular cloning, tissue expression and nutritional regulation of a Δ6 fatty acyl desaturase-like (Δ6 Fad-like) gene from mud crab, Scylla paramamosain. The full-length cDNA was 1973bp, with a 201bp of 5'-UTR, a 443bp of 3'-UTR, and an ORF of 1329bp that encoded a protein of 442 amino acids. Bioinformatics analysis showed that the deduced peptide sequence possessed the typical features of the microsomal Fads, including N-terminal cytochrome b5domain containing the heme-binding motif (H-P-G-G), three histidine-rich boxes and three membrane-spanning regions. Sequence comparison revealed that the predicted protein had a high percentage identity (>53%) with Δ6 Fads from other crustacean species. The tissue distribution of mud crab Δ6 Fad-like mRNA was found predominantly in hepatopancreas, with lower expression levels in all other tissues. Quantitative real-time PCR showed that the Δ6 Fad-like transcriptional levels in hepatopancreas gradually increased with the increased replacement of dietary fish oil (FO) by soybean oil (SO). The replacement ratio of FO by SO up to 60%, 80%, and 100% were significantly up-regulated by about 2.40-fold, 2.99-fold and 3.02-fold compared with that in the control group (100% FO) respectively (P<0.05). These results may contribute to better understanding the HUFA biosynthetic pathway and regulation mechanism in this species.
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China.
authors.forename: Zhideng
authors.initials: Z
authors.lastname: Lin
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou 510642, PR China.
authors.forename: Meilin
authors.initials: M
authors.lastname: Hao
authors.affiliation: College of Animal Science, Yangtze University, Jingzhou 434023, PR China.
authors.forename: Dashi
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China.
authors.forename: Shengkang
authors.initials: S
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China. Electronic address: wenxbo@stu.edu.cn.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Wen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003386:Brachyura / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D003001:Cloning, Molecular; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D043143:Hepatopancreas / Q000378:metabolism*; D050602:Linoleoyl-CoA Desaturase / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D005231:Fatty Acids, Unsaturated; D012333:RNA, Messenger; D050602:Linoleoyl-CoA Desaturase
keywords: Cloning; HUFA; Mud crab; Nutritional regulation; Δ6 Fad-like