摘要
以4～35月龄三倍体雌性虹鳟(Oncorhynchus mykiss)为实验材料,以同源二倍体为对照,采用组织学和放射免疫方法,从性腺发育和生殖激素变化2个方面对其类雄性化现象进行了研究,并分析了类雄性化的原因。结果表明,三倍体虹鳟的卵原细胞可正常发育至卵黄发育前期卵母细胞(8月龄左右),此后卵母细胞败育,基质细胞包围卵原细胞形成卵原细胞簇,17月龄后卵巢中卵原细胞簇减少,出现与雄性精小囊结构相似的类生精细胞囊结构;26～35月龄类生精细胞囊逐渐成为性腺的主要成分,在类生精细胞囊内出现大量坏死的细胞;13月龄后三倍体雌性虹鳟血清中GtH-Ⅰ、GtH-Ⅱ、17β-E2含量显著低于同期二倍体虹鳟,睾酮(T)在21月龄后持续上升,并显著高于同期二倍体(P<0.05)。17月龄后三倍体雌性虹鳟卵巢发育呈现类雄性化趋势,但不能完成精子发生全部过程。由于性腺中生殖细胞与体细胞之间正常的相互作用缺失,合成类固醇的滤泡细胞发育分化受阻,T芳化为17β-E2途径中断,导致血液中T浓度升高,进而使性原细胞的分化受到了诱导,因而卵巢发育呈现类雄性化趋势。
Triploid female rainbow trout（ Oncorhynchus mykiss） of 4-35 months old were sampled（ diploids at the same stage as controls） and analyzed using histological and radioimmunoassay. From two aspects of both gonadal development and changes of reproductive hormone,we tried to explore the virilescent-like phenomenon and find out the mechanism of it. The results displayed that oogonium of triploid could normally develop into prophase oocytes of vitelline development at about 8 months old after these necrosis occurred. Oogonium were surrounded by stroma cells to form oogonial cluster,after 17 months old when the number of oogonial cluster decreased,forming a structure which resembled spermatogonial cysts in male and were named spermatogenic-like cytocysts. Spermatogenic-like cytocysts became the major components of gonad in the samples from 26 to 35 months old,and many necrotic cells were in it. Blood hormone levels of GtH-Ⅰ,GtH-Ⅱ and 17β-E2 were significantly lower than those in diploid after 13 months old,respectively. Blood T level experienced a constantly rising process after 21 months old and was higher than that in diploid（ P〈 0.05）. The results indicated that 17-month-old triploid female presented a tendency of virilescent,but did not experience the whole process of spermatogenesis. Because of lack of normal interactions of somatic cells and germinal cells,development and differentiation of follicle cells in which steroid synthesized were blocked,the path of T arylated as 17β-E2 was interrupted,resulting in a rising level of blood T and then inducing the differentiation of gonocytes,making the gonad present the trend of virilescent.
出处
《中国水产科学》
CAS
CSCD
北大核心
2010年第4期739-744,共6页
Journal of Fishery Sciences of China
基金
黑龙江省科技攻关项目(GA06B203)
关键词
三倍体雌性虹鳟
类雄性化
卵巢发育
生殖激素
triploid female rainbow trout
virilescent-like phenomenon
ovarian development
reproductive hormone
