Androstenedione and 17α-methyltestosterone induce early ovary development of Anguilla japonica
Androstenedione and 17α-methyltestosterone induce early ovary development of Anguilla japonica
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DOI：
10.1016/j.theriogenology.2018.07.009
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发表时间：
2018-10-15
期刊：
影响因子：
2.8
通讯作者：
Wang, Yi-Lei
中科院分区：
文献类型：
--
作者：
Lai, Xiao-Jian;Li, Zhong-Qin;Wang, Yi-Lei
11-酮睾酮（11-ketosterone，11-KT）是一种非芳香化雄激素，在鳗鲡生殖的卵黄发生前期对卵泡生长的调节作用已被广泛阐明。然而，芳香化雄激素在卵子发生过程中对脑-垂体-性腺轴的影响尚不清楚。japonica没有被明确阐述。本研究采用雄烯二酮（AD）和17 α-甲基睾酮（MT）联合诱导7龄雌性日本鳗鲡（Anguilla japonica）在洄游季节进行投喂或暴露，以诱导其卵巢发育。在雌性A.在淡水条件下，用AD和MT各5 mg/kg·d ~（-1）的商品饲料饲养45 d（试验Ⅰ），卵母细胞的发育仍停留在油滴期，但GSI和卵泡直径显著增大。血清11-KT水平和肝脏卵黄蛋白原mRNA表达显著升高。将雌鱼分别暴露于含50 μ g L ~（-1）AD和MT的海水中45 d后（试验Ⅱ），A. japonica几乎进入卵黄中期，GSI和卵泡直径显著增大。卵质周围可见卵黄颗粒层。血清11-KT水平维持在较低水平，血清E2水平显著下降至较低水平。卵巢ar α和cyp 19 α 1、脑mGnRH和lh β的表达水平显著升高。结果表明：A.试验Ⅱ的粳稻卵巢发育高于试验Ⅰ。结果表明，AD和MT能增加卵黄发生前期的油滴形成和增大卵泡直径，而试验Ⅰ则无卵黄发生和促性腺激素释放。在试验II中，AD和MT通过刺激卵巢ara的表达以及上调脑mGnRH和垂体LH β的表达来促进卵黄发生。(C)2018爱思唯尔公司All rights reserved.
Endocrine effects as 11-ketotestosterone (11-KT), an unaromatizable androgen, regulating the follicles growth in the previtellogenic stage of eel reproduction have been widely elucidated. However, the influence of aromatizable androgens on the brain-pituitary-gonad axis during oogenesis in A. japonica has not been clearly elaborated. In the study, androstenedione (AD) and 17 alpha-methyltestosterone (MT) were employed together to induce ovary development of seven-year-old female Anguilla japonica through feeding or exposure in the migration season. After female A. japonica had been fed with commercial diet containing 5 mg AD and MT kg d(-1) body weight respectively for 45 d in fresh water (Trial I), the development of oocytes still remained at the oil droplet stage, but the GSI and follicle diameter increased significantly. The serum 11-KT level and expression of liver vitellogenin mRNA were significantly elevated. After female fish had been exposed to seawater containing 50 mu g L-1 AD and MT respectively for 45 d (Trial II), the ovaries of A. japonica almost reached midvitellogenic stage and the GSI and follicle diameter increased significantly. Yolk granular layer was observed in the peripheral ooplasm. The serum 11-KT level maintained consistently low, and the serum E2 level declined significantly to a relatively low level. The expression levels of ovarian ar alpha and cyp19al, brain (with pituitary together) mGnRH and lh beta increased significantly. The results showed that A. japonica in Trial II appeared a higher ovarian development than those in Trial I. These findings indicated that AD and MT increased the oil droplet and enlarged follicle diameter in previtellogenic stage, while the vitellogenesis and gonadotropin release did not occur in Trial I. In Trial II, AD and MT promoted vitellogenesis by stimulating the ovary expression of ara and by up-regulating brain mGnRH and pituitary lh beta expression. (C) 2018 Elsevier Inc. All rights reserved.