In the aquaculture industry, fish oil is widely used as a nutritional supplement to promote the gonadal maturation of broodstocks, while the mechanism of fish oil on ovary development remain unclear. Herein, female adult spotted scat (Scatophagus argus) with most ovaries at phase II were fed with diets containing 8% soybean oil (SO) or 8% fish oil (FO) for 60 days. The final average fish body weight was similar between FO and SO groups. The average gonadosomatic index (GSI) of FO group was higher (non-significant) than that of SO group. Finally, the phase IV ovary of the FO and SO groups were 7 and 5 out of 10, respectively. The serum estradiol (E2) level of the FO group was significantly higher than that of the SO group. The proportions of n-3 long-chain polyunsaturated fatty acids (LC-PUFA, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) in the ovaries were much higher in the FO group than in the SO group. These results suggest that the maturity level of the FO group is relatively higher than that of the SO group. Transcriptome sequencing was used to detect the ovary gene expression. Comparatively, the ovary transcriptome analysis showed 68 up-regulated and 193 down-regulated genes in the FO group. The expression levels of Jund and Jun necessary for the ovary maturation were up-regulated in the FO group, while Pparγ and Cxcl12, which could inhibit the ovary development, were down-regulated in the FO group. Cyp3a27 coding the enzyme for degrading the estrogen was significantly down-regulated in the FO group and coincided with the increase of its serum E2. Kif5b which could regulate the glucose metabolism was up-regulated in the FO group. Serum insulin level was also increased in the FO group. Additionally, Aldh3a2 and Plin2 related to lipid metabolism were significantly down-regulated in the FO group. Briefly, dietary fish oil can influence the expression of genes related to steroid hormone, glucose and lipid metabolism. This study will clarify the mechanism of dietary fish oil in promoting ovary development in teleost fish.

在水产养殖业中，鱼油被广泛用作促进亲鱼性腺成熟的营养补充剂，而鱼油对卵巢发育的作用机制尚不清楚。在此，雌性成年斑点粪便（鲶鱼) 在第 II 阶段，大多数卵巢被喂食含有 8% 大豆油 (SO) 或 8% 鱼油 (FO) 的日粮 60 天。FO 组和 SO 组之间的最终平均鱼体重相似。FO组的平均性腺体指数（GSI）高于（不显着）SO组。最后，FO 组和 SO 组的 IV 期卵巢分别为 10 个中的 7 个和 5 个。FO组血清雌二醇(E2)水平明显高于SO组。FO组卵巢中n-3长链多不饱和脂肪酸（LC-PUFA，如二十二碳六烯酸（DHA）和二十碳五烯酸（EPA））的比例远高于SO组。这些结果表明，FO 组的成熟度水平相对高于 SO 组。转录组测序用于检测卵巢基因表达。相比之下，卵巢转录组分析显示 FO 组中有 68 个上调基因和 193 个下调基因。的表达水平君德和君卵巢成熟所必需的在 FO 组中上调，而Pparγ和CXCL12，可抑制卵巢发育，在 FO 组中下调。Cyp3a27编码雌激素降解酶在 FO 组中显着下调，并与其血清 E2 升高同时发生。Kif5b在FO组中可以调节葡萄糖代谢的上调。FO组的血清胰岛素水平也升高。此外，aldh3a2和普林2FO组中与脂质代谢相关的显着下调。简而言之，膳食鱼油可以影响类固醇激素、糖脂代谢相关基因的表达。本研究将阐明日粮鱼油促进硬骨鱼卵巢发育的机制。