Analyses on mechanisms of eel oogenesis for the improvement of egg quality

鳗鱼卵子生成提高蛋品质的机制分析

基本信息

批准号：
14206022
负责人：
YAMAUCHI Kohei
金额：
$ 34.11万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

The control of 11-ketotestosterone (11KT) biosynthesis and its physiological roles were examined in female eel. Among various tissues, the ovary had the greatest capacity to synthesize 11KT in vitro. In addition, the oocyte diameters of eels treated with 11KT had increased significantly. Furthermore, these oocytes were found to have an increased number of oil droplets. These findings suggest that 11KT appears to play an important role in controlling previtellogenic oocyte growth. In the next, we examined the effects of oral administration of other androgens, 17α-methyltestosterone (MT) on the previtellogenic oocyte growth. Female eels that have oocytes of about 40 μm in diameter were fed the diets containing MT for two and four months. However, significant differences were not observed. In the next, female eels that have oocytes of about 90 μm were fed the diets containing MT. Oocyte diameters in the MT treated group increased with greater abundance of oil droplets. These results indicate that the oral administration of MT can induce growth of previtellogenic oocytes over 90 μm in diameter in eel.During artificiall maturation, serum estradil-17β(E2) levels in female eel change at relatively lower values till the mid-vitellogenic stage, then elevate linearly to reach maximum levels at even the migratory nucleus stage. Aromatase inhibitor could suppress the higher levels of serum E2.In this study, we generated and characterized polyclonal antisera against eel P450 cholesterol side-chain cleavage (P450scc), 17α-hydroxylase, aromatase and 11β-hydroxylase using recombinant proteins as antigens. These antisera immunostained specific cells in ovary of eel. Among them, the P450scc antiserum clearly immunostained interrenal steroidogenic cells in head kidney of not only eel but also goldfish, indicating that this antibody are also utilizable for other teleost species.

在雌性鳗鱼中检查了11-酮睾酮（11KT）生物合成的控制及其生理作用，在体外，卵巢具有最大的合成11KT的能力，并且经11KT处理的鳗鱼的卵母细胞直径显着增加。此外，这些卵母细胞的油滴数量有所增加，这些发现表明 11KT 似乎在控制卵黄发生前发挥着重要作用。接下来，我们研究了口服其他雄激素 17α-甲基睾酮 (MT) 对卵黄形成前卵母细胞生长的影响，将卵母细胞直径约为 40 μm 的雌性鳗鱼喂食含有 MT 的饲料两次和两次。然而，在接下来的四个月中，卵母细胞直径约为 90 μm 的雌性鳗鱼喂食含有 MT 卵母细胞直径的饲料。这些结果表明，口服MT可以诱导鳗鱼卵黄发生前卵母细胞直径超过90μm的生长。在人工成熟过程中，雌性鳗鱼血清雌二醇17β（E2）水平相对较低。直到卵黄发生中期，然后线性升高，甚至在迁移核阶段达到最高水平，芳香酶抑制剂也可以抑制血清 E2 的较高水平。在这项研究中，我们产生了。并以重组蛋白为抗原，对鳗鱼P450胆固醇侧链裂解酶（P450scc）、17α-羟化酶、芳香酶和11β-羟化酶的多克隆抗血清进行了表征，这些抗血清对鳗鱼卵巢中的特定细胞进行了免疫染色。不仅鳗鱼的头肾中存在类固醇生成细胞，金鱼的头肾中也存在类固醇生成细胞，这表明抗体也可用于其他硬骨鱼物种。