维生素C对圆斑星鲽早期发育的影响

本研究旨在探究维生素C(V_C)对圆斑星鲽(Verasper variegatus)早期发育中孵化率、出膜率和成活率的影响,对其消化酶和脂蛋白脂酶(Lipoprotein lipase,LPL)及肝脂酶(Hepatic Lipase,HL)的影响。实验用圆斑星鲽为人工受精卵,分为5组,孵化水体V_C浓度分别为0、20、25、30和35 mg/L,分别在成熟卵、受精卵、原肠中期、晶体出现期、内源营养期(2日龄)、混合营养期(6日龄)及外源营养期(9日龄)取样。记录圆斑星鲽的出膜时间、出膜率和成活率,测定对照组和生长指标优越组的消化酶活性和2种酯酶的活性。结果显示,25 mg/L的V_C能显著提高圆斑星鲽的出膜率和成活率,并缩短出膜时间(P0.05)。V_C能促进圆斑星鲽早期发育过程中蛋白质的沉积。外源营养期后,胃蛋白酶活性显著提高(P0.05),淀粉酶活性在混合营养期显著提高(P0.05),脂肪酶和胰蛋白酶活性在内源营养期就显著提高(P0.05)。25 mg/L V_C溶液浸泡使圆斑星鲽胚胎发育过程中的LPL和HL比活力显著升高(P0.05)。合子中的LPL和HL基因可能在原肠期开始表达,合成脂质水解酶分解脂质,为胚胎发育供能。研究表明,圆斑星鲽成熟卵受精后脂肪酶和胰蛋白酶酶优先发挥作用,分解卵黄中的碳水化合物为胚胎发育迅速提供能量。25 mg/L的V_C能显著提高消化酶活性,并促进蛋白质的沉积,有利于孵化成活的V_C浓度可以显著促进圆斑星鲽早期发育的脂质代谢。

Effects of Vitamin C on Early Development of Spotted Halibut (Verasper variegatus)

This study investigated effects of exogenous Vitamin C (VC) on the membrane time, hatching ratio, survival rate, growth characteristics, digestive enzyme activities and Lipases enzyme activities of spotted halibut (Verasper variegatus) during early development using mature eggs by the method of artificial fertilization. The eggs were divided into five groups with five different VC concentration of 0, 20, 25, 30, and 35 mg/L, respectively. Samples were collected at mature eggs, fertilized eggs, mid-gastrula, crystal appear, mixed nutrition and exogenous nutrition stages. The results showed that 25 mg/L VC significantly improved the hatching ratio, survival rate and growth characteristics and shorten the membrane time, and that VC contributed to the deposition of protein in spotted halibut during early development, and significantly enhanced the activity of pepsin after exogenous nutrition stage (P<0.05). After mixed nutrition stage, VC significantly increased the activity of amylase (P<0.05). After endogenous nutrition stage, VC significantly induced the activity of lipase and trypsin (P<0.05). VC at 25 mg/L increased the activities of lipoprotein lipase and hepatic lipase enzyme during embryo development (P<0.05). The findings indicated that lipoprotein lipase and hepatic lipase genes in zygotes may play functions at gastrula stage when lipid hydrolytic enzymes express to release energy for embryonic development. The results demonstrate that lipase and trypsin priority digest carbohydrates in yolk of mature eggs from spotted halibut to provide energy for embryonic development right after fertilization. The study revealed that appropriate level of VC could improve lipid metabolism during embryo development of spotted halibut.