Characterization of fatty acid delta-6 desaturase gene in Nile tilapia and heterogenous expression in Saccharomyces cerevisiae.
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.
School of Animal Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Muang, Nakhon Ratchasima 30000, Thailand.
Supamas
S
Tanomman
Mariena
M
Ketudat-Cairns
Araya
A
Jangprai
Surintorn
S
Boonanuntanasarn
D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004534:Egypt; D015971:Gene Expression Regulation, Enzymologic; D050602:Linoleoyl-CoA Desaturase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D045483:Rivers; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D017210:Tilapia / Q000235:genetics* / Q000378:metabolism
D018076:DNA, Complementary; D012333:RNA, Messenger; D050602:Linoleoyl-CoA Desaturase
Delta-6 desaturase; Nile tilapia; Recombinant yeast; Saccharomyces cerevisiae; fads2