Characterization of fatty acid delta-6 desaturase gene in Nile tilapia and heterogenous expression in Saccharomyces cerevisiae

• Published in: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 2013-10, Vol.166 (2), p.148-156
• Main Authors: Tanomman, Supamas, Ketudat-Cairns, Mariena, Jangprai, Araya, Boonanuntanasarn, Surintorn
• Format: Article
• Language: English
• Subjects: Animals; Brackish; brain; Cloning, Molecular; Delta-6 desaturase; DNA, Complementary - genetics; eggs; Egypt; fads2; galactose; gene expression; Gene Expression Regulation, Enzymologic; genes; hatching; Linoleoyl-CoA Desaturase - genetics; Linoleoyl-CoA Desaturase - isolation & purification; Linoleoyl-CoA Desaturase - metabolism; liver; Nile tilapia; Oreochromis niloticus; Plasmids; Promoter Regions, Genetic; Recombinant yeast; reverse transcriptase polymerase chain reaction; Rivers; RNA, Messenger - genetics; Saccharomyces cerevisiae; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - genetics; testes; Tilapia - genetics; Tilapia - metabolism; yeasts
• ISSN: 1096-4959; 1879-1107
• DOI: 10.1016/j.cbpb.2013.07.011

Fatty acid delta-6 desaturase (fads2)-like gene from Nile tilapia (Oreochromis niloticus) was characterized and designated as oni-fads2. The Oni-FADS2 showed the typical structure of microsomal FADS2. The presence of oni-fads2 transcripts in unfertilized eggs demonstrated the maternal role of Nile tilapia in providing the oni-fads2 transcript in their eggs. In addition, the expression of oni-fads2 was detectable in embryos throughout the hatching stage. Real-time reverse transcription-PCR revealed that oni-fads2 was expressed at a high level in all the brain regions, liver, and testis. Recombinant yeast (RY) was generated by transformation of Saccharomyces cerevisiae with the plasmid containing oni-fads2 driven by the Gal1 promoter (pYoni-fads2). The conspicuous expression of RY was detectable by RT-PCR after induction with galactose for 24h. When RY was induced with galactose, it exhibited 39% and 7% of delta-6 desaturase (∆6) activity toward C18:2n6 and C18:3n3, respectively. Additionally, it displayed 4% of delta-5 desaturase (∆5) activity toward C20:3n6, indicating that Oni-FADS2 had ∆5 and ∆6 bifunction.