本实验旨在评估锌的分级水平对濒危cat鱼卵黄蛋白原基因(Vtg)表达和抗氧化酶的影响。Clariasmagur(C.magur)。将180只平均体重为145±5g的雌性C.magur分配在12个尺寸为4.5×2×1m的水泥罐中,为期60天。按照完全随机的设计,将鱼分成4组,重复3次。第一组作为对照组(C)饲喂基础日粮含有正常的锌水平,其余组分别饲喂含50、200和300mg/kg醋酸锌的基础饮食,分别作为T1,T2和T3处理。评价日粮补锌对Vtg基因表达的影响,进行了三次抽样,我采样(4月,在开始实验之前),II抽样(5月,喂养试验1个月后)和III采样(繁殖季节前6月)。在本研究中,Vtg基因表达与受威胁cat鱼饮食中锌含量之间的剂量依赖性关系,C.magur,已报告。从I采样到II采样,所有组的Vtg基因表达均增加,但T1组的Vtg基因表达最高,而T3组的Vtg基因表达最低。Vtg基因表达在各采样处理中差异显著(P<0.05)。通过电感耦合等离子体原子发射光谱(ICP-AES)在C.magur中测量锌的积累,据报道,与其他组相比,T3组的肝脏和卵巢中的锌积累显著更高(P<0.05)。抗氧化酶活性(超氧化物歧化酶,SOD,过氧化氢酶和GST)也在不同的组织(肝脏,g和卵巢)以评估额外补充锌对抗氧化状态的影响。在T3组中,SOD,过氧化氢酶和GST活性明显高于其他组。在目前的研究中,还测量了血清葡萄糖水平,发现在C.magur饮食中包含锌呈增加趋势。在本研究中,可以得出结论,锌仅在高达50mg/kg时表现出有益效果。因此,结论是,以200mg/kg或更高的剂量补充锌会破坏Vtg基因表达和抗氧化状态。
The present experiment was designed to evaluate the effect of graded level of zinc on Vitellogenin gene (Vtg) expression and antioxidant enzymes in threatened catfish, Clarias magur (C. magur). One hundred and eighty female C. magur with an average weight of 145 ± 5 g were allocated in twelve cemented tanks with dimension 4.5 × 2 × 1 m for a period of 60 days. Fish were distributed in four groups with three replicates following the completely randomised design. The first group treated as control (C) fed with basal diet contained normal zinc level, and remaining groups were fed with basal diets having 50, 200 and 300 mg/kg zinc acetate and treated as T1, T2 and T3 respectively. To evaluate the effect of dietary zinc supplementation on Vtg gene expression, three sampling were carried out, I sampling (April, before starting the experimental trail), II sampling (May, after 1 month of feeding trail) and III sampling (June before breeding season). In the present study, a dose-dependent relationship between Vtg gene expression and zinc inclusion in the diet of threatened catfish, C. magur, was reported. Vtg gene expression increased in all groups from I sampling to II sampling but the highest Vtg gene expression was found in T1 group and the lowest in T3 group at II sampling. Vtg gene expression among the treatments differs significantly (P < 0.05) in each sampling. Accumulation of zinc was measured by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) in C. magur and it was reported that the significantly higher (P < 0.05) zinc was accumulated in the liver and ovary of T3 group as compared to other groups. The antioxidant enzyme activities (superoxide dismutase, SOD, catalase and GST) were also measured in different tissues (liver, gill and ovary) to evaluate the effect of extra-supplementation of zinc on the antioxidant status. In T3 group, SOD, catalase and GST activities were significantly higher than those in other groups. In the current study, serum glucose level was also measured and it was found in increasing trend with inclusion of zinc in the diet of C. magur. In the present study, it can be concluded that the zinc exhibits beneficial effect only up to 50 mg/kg. Thus, it is concluded that supplementation of zinc at 200 mg/kg or more disrupts Vtg gene expression and antioxidant status.