银鲫精子在两性融合生殖鱼类卵质中的受精特征

FERTILIZATION CHARACTERISTICS OF THE SPERM OF GYNOGENETIC CRUCIAN CARP (CARASSIUS AURATUS GIBELIO) IN THE EGG OF AMPHIMICTIC FISH

  • 摘要: 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。

     

    Abstract: Cytological study on the fertilization with sperms of gynogenetic crucian carp and eggs of amphimietie common carp has been made in order to reveal the mechanism which leads to the death of the hybrid embryos. It showed that the sperms were able to transform into male pronuclei and fuse with female pronuclei, so that the zygotic nuclei were formed. However, after the beginning of cleavage, some unusual phenomena, such as the elimination of chromosomes, the formation of multiple spindles and the asynchronous division of the two blastomeres of the same egg, were observed. From these results, the authors are preliminarily of the opinion that, between gynogenetic crucian carp and other fishes, there exists a certain chromosome incompatibility which leads to the repelling of chromosomes in the hydrid embryonic cells. probably, this reflects the unique genetic background of the chromosome complement of gynogenetic crucian carp.

     

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