Optimal dietary lipid level promoted ovary development of Chinese sturgeon (Acipenser sinensis) broodstocks

A one-year feeding trial was conducted to determine the effects of dietary lipid level on gonad development and steroidogenesis-related gene expressions of Chinese sturgeon (Acipenser sinensis). Three isonitrogenous experimental diets (L10, L14 and L18) were compounded with different lipid levels. Results of the feeding trial showed that 2 female Chinese sturgeons in L18 group had developed the ovary to stage III. Chi-square independence test indicated that ovary development was significantly affected by dietary lipid level (P < .05). Po and d values of ovary also increased with dietary lipid level. Serum estradiol (E-2) and testosterone (T) of L14 group was significantly higher than those in the other two groups (P < .05). Blood urea nitrogen (BUN) content decreased as dietary lipid level increased, while triglyceride (TG) and glucose (GLU) contents increased with dietary lipid level (P < .05). Vitellogenin receptor (vtgr) mRNA expression increased with dietary lipid level (P < .05); Gene expressions of androgen receptor (ar), cytochrome p450 17A1 (cyp17a1), steroidogenic acute regulatory protein (star), follicle stimulating hormone receptor (fshr), luteinizing hormone receptor (lhr) and cytochrome p450 aromatase (cyp19a1) were significantly higher in L14 group than in other groups (P < .05), whereas mRNA expression of leptin receptor (lepr) and DNA-binding protein inhibitor ID-1 (dbi) in L14 group were significantly lower (P < .05). Based on the gonad development, higher dietary lipid level (16.31%) would promote ovary development of Chinese sturgeon broodstocks through the elevation of vtgr expression to increase the assimilation of vitellogenin in ovary.