银鲫精子在两性融合生殖鱼类卵质中的受精特征

红鲤(♀)×银鲫(♂)的杂种胚胎均不能成活。受精细胞学研究结果表明,雌核发育银鲫的精核在两性融合生殖的鲤鱼卵质中能转化为雄性原核,并和雌性原核融合成合子核。但在卵裂开始后,可观察到某些异常现象,如染色体丢失,多极纺锤体形成,以及第二次卵裂时受精卵的两分裂球的非同步性分裂等。我们初步认为,雌核发育银鲫的染色体和两性融合生殖的鱼类染色体之间存在某种不相容性,表现为彼此间的互相排斥。出现这种现象可能和银鲫染色体组的雌核发育遗传背景有关。

雌核发育和两性融合发育鱼卵调控精核受精发育的生化特性研究

两性融合生殖的鱼卵受精后，精核能疏松、解凝，形成雄性原核：雌核发育银鲫卵子受精后，精核发育受到抑制，无法形成原核。采用显微注射去膜精核以及细胞学和电镜观察的方法，本文对两类鱼卵受精后精核早期发育的生化性质进行了初步探讨，并着重研究了雌核发育银鲫卵子控制精核发育的生化特征。实验结果显示，两性融合生殖鱼类卵质中，一定量的Ｃａ２＋的存在，二硫键的还原作用对于精核的发育显然是必要的；而在雌核发育银鲫卵中，Ｃａ２＋的功能和二硫键的还原作用与精核发育受到抑制之间并无直接联系。银鲫卵质中似乎显示出异常的磷酸酶脂解活性，导致磷酸化过程无法进行，使精核解凝受到阻碍。另外，两性融合生殖的鱼卵重质层中具有大量诱导精核原核化的有关因子，而银鲫卵质中则缺少该因子（或活性极低）。银鲫卵质中还可能缺乏某些与雄性原核的核膜重组装有关的大分子物质。

Comparative investigation on spindle behavior and MPF activity changes during oocyte maturation between gynogenetic and amphimictic crucian carp

The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp. MPF activity was measured by using histone H1 as phosphorylation substrate. There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes, but there existed some subtle difference between them. The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp. It was suggested that the difference may be related to the spindle behavior changes, such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.