Effect of dietary n-3 polyunsaturated fatty acid supplementation on the expression of genes involved in progesterone biosynthesis in the corpus luteum of goat (Capra hircus)

Emerging evidence indicates that dietary n-3 polyunsaturated fatty acids (PUFA) alter the fatty acid composition of corpus luteum (CL) and directly affect the luteal function in the cow, which is independent of the inhibitory effect on the endometrial PGF(2 alpha) production. The present study, thus, investigated the effects of n-3 PUFA rich fish oil (FO) supplementation on the transcriptional modulation of genes involved in the biosynthesis of progesterone (P-4) in the CL collected during the luteolytic phase of oestrous cycle in the goat. On the day of synchronized oestrus, goats (n = 6/group) were fed an isocaloric diet supplemented with either FO or palm oil (PO). The dose of oil supplementation was 0.6 mlkg(-1) body weight, and the duration was 55-57 days. The FO provided 156 mgkg(-1) body weight of n-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The CL was collected by laparotomy on day 16 post-oestrus, and the relative abundance of P450 side-chain cleaving enzyme, steroid acute regulatory protein (StAR) and 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD) genes was quantitated by real-time PCR. The results indicated that the dietary FO significantly upregulated the expression of 3 beta-HSD by 1.13-fold and downregulated StAR by similar to 2-fold as compared to PO group (p < .05). It is concluded that dietary FO differently affected the expression of genes involved in P-4 synthesis in the CL during the luteolytic window of the oestrous cycle in the goat.