title: Functional characterization of a Δ5-like fatty acyl desaturase and its expression during early embryogenesis in the noble scallop Chlamys nobilis Reeve.
abstract: Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential in lots of important physiological processes, while, many marine species have no or limited ability of endogenous PUFA biosynthesis, normally due to the lack of key enzymes such as fatty acid desaturase (FAD). In this study, we isolated a scallop Chlamys nobilis cDNA with high homology to vertebrate FADs. Functional characterization in recombinant yeast Saccharomyces cerevisiae showed that scallop FAD exhibited Δ5-desaturation activity towards both saturated and PUFA substrates. Thus, it efficiently desaturated exogenously added PUFA C20:4(n - 3) and C20:3(n - 6) to C20:5(n - 3) (EPA) and C20:4(n - 6) (ARA) respectively. It also converted the yeast's endogenous C18:0 into C18:1(n - 13), and participated in the biosynthesis of non-methylene-interrupted FA by introducing a double bond to C20:3(n - 3) and C20:2(n - 6) in the Δ5 carbon. Temporal transcript profile of scallop FAD was studied during early embryonic development. High level of mRNA was found at the beginning of embryogenesis (egg) and noticeable decreases of were observed during larvae development, suggesting maternal FAD mRNA transfer to the embryo. Further, FAD transcripts were detected in all tissues analyzed, with the gonad and hepatopancreas showing the highest expression.
authors: Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China.
authors: Helu
authors: H
authors: Liu
authors: Zhicheng
authors: Z
authors: Guo
authors: Huaiping
authors: H
authors: Zheng
authors: Shuqi
authors: S
authors: Wang
authors: Yajun
authors: Y
authors: Wang
authors: Wenhua
authors: W
authors: Liu
authors: Guofan
authors: G
authors: Zhang
mesh_terms: D000818:Animals; D001483:Base Sequence; D002849:Chromatography, Gas; D003001:Cloning, Molecular; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D000090943:Delta-5 Fatty Acid Desaturase; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D049897:Pectinidae / Q000196:embryology* / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D000090943:Delta-5 Fatty Acid Desaturase; D005231:Fatty Acids, Unsaturated; D044943:Fatty Acid Desaturases