کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5906473 | 1159972 | 2013 | 7 صفحه PDF | دانلود رایگان |
- The Î6Fad-a and Î6Fad-b genes were not allelic variants of a single gene.
- Both Î6Fad-a and Î6Fad-b genes were highly expressed in liver, intestine and brain.
- The Î6Fad-a was regulated, whereas Î6 Fad-b was not affected by temperature.
- The Î6Fad-a and Î6Fad-b genes have different nutritional roles in different tissues.
Î6-Desaturase is the rate-limiting enzyme involved in highly unsaturated fatty acid (HUFA) biosynthesis. There is very little information on the evolution and functional characterization of Î6Fad-a and Î6Fad-b in common carp (Cyprinus carpio var. Jian). In the present study, the genomic sequences and structures of two putative Î6-desaturase-like genes in common carp genome were obtained. We investigated the mRNA expression patterns of Î6Fad-a and Î6Fad-b in tissue, hatching carp embryos, larvae by temperature shock and juveniles under nutritional regulation. Our results showed that the two Î6Fad genes had identical coding exon structures, being comprised of 12 coding exons, and with introns of distinct size and sequence composition. They were not allelic variants of a single gene. Both Î6Fad genes were highly expressed in liver, intestine (pyloric caeca) and brain. The Î6Fad-a and Î6Fad-b mRNAs showed an increase in expression from newly hatched to 25 days after hatching. The expression levels of Î6Fad-a were obviously regulated by temperature, whereas Î6Fad-b was not affected by temperature. The regulation of Î6Fad-a and Î6Fad-b in response to dietary fatty acid composition was determined in liver, brain and intestine (pyloric caeca) of common carp fed with diets: diet1with fish oil (FO) rich in n â 3 HUFA, diet2 with corn oil (CO, 18:2n â 6) and diet3 with linseed oil (LO, 18:3n â 3). The differential expression of Î6Fad-a and Î6Fad-b genes in liver, brain and intestine in common carps was fed with different oil sources, respectively. Further work is in progress to determine the mechanism of differential expression of the Î6Fad-a and Î6Fad-b genes in different tissues and the roles of transcription factors in regulating HUFA synthesis.
Journal: Gene - Volume 525, Issue 1, 1 August 2013, Pages 11-17