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-酮替酮（11KT）生物合成及其身体作用的控制。在各种组织中，卵巢在体外合成11KT的能力最大。此外，用11KT处理的鳗鱼的卵母细胞直径显着增加。此外，发现这些卵母细胞的油滴数量增加。这些发现表明，11KT似乎在控制前卵母细胞生长中起着重要作用。接下来，我们检查了其他雄激素，17α-甲基睾丸激素（MT）对预胞胶卵母细胞生长的影响。将直径约为40μm的卵母细胞的雌性鳗鱼喂食含有MT的饮食两个和四个月。但是，未观察到显着差异。接下来，将卵母细胞约为90μm的雌性鳗鱼喂食含有MT的饮食。 MT处理组中的卵母细胞直径增加，油滴的丰度增加。这些结果表明，MT的口服可以诱导鳗鱼直径超过90μm的预卵母细胞的生长。在人工体成熟，女性EEL的血清estradil-17β（E2）水平相对较低的值中，雌性EEL的水平相对较低，直到中速度阶段，然后在线性级别上升高至最高水平。芳香酶抑制剂可以抑制较高水平的血清E2。在这项研究中，我们使用再生蛋白抗原蛋白产生了针对EEL P450胆固醇侧链裂解（P450SCC），17α-羟化酶，芳香酶和11β-羟化酶的多克隆抗血清。其中，P450SCC抗血清清楚地在鳗鱼和金鱼的头部肾脏中进行了免疫染色的内部类固醇生成细胞，这表明该抗体也可用于其他硬骨鱼类。