Dietary n-3 LC-PUFAs affect lipoprotein lipase (LPL) and fatty acid synthase (FAS) activities and mRNA expression during vitellogenesis and ovarian fatty acid composition of female silver pomfret (Pampus argenteus) broodstock

We studied the effects of dietary n-3 LC-PUFAs on the activities and mRNA expression levels of tissue lipoprotein lipase (LPL) and fatty acid synthase (FAS) during vitellogenesis and ovarian fatty acid composition in female silver pomfret broodstock. Broodstock were fed one of four experimental diets for 185 days: FO (100% fish oil), FSO (70% fish oil + 30% soybean oil), SFO (30% fish oil + 70% soybean oil) or SO (100% soybean oil). The results revealed that hepatic LPL and FAS and ovarian FAS activities and mRNA expression levels significantly increased at vitellogenesis and postvitellogenesis relative to previtellogenesis, with no significant differences between these two stages, except for hepatic LPL mRNA expression. Dietary n-3 LC-PUFAs decreased tissue FAS and increased LPL activities and mRNA expression levels. The ovarian concentrations of 20:4n-6 (ARA), 20:5n-3 (EPA), 22:6n-3 (DHA) and n-3 LC-PUFAs were directly influenced by n-3 LC-PUFA levels. Total n-3 LC-PUFA concentrations in SO were 57% lower than those in FO, while 18:2n-6 concentrations in SO were 4.7 x higher than those in FO. These results revealed that high dietary n-3 LC-PUFAs levels significantly affected tissue lipid metabolism in female silver pomfret broodstock during vitellogenesis by upregulating LPL and downregulating FAS.