天然雌核发育银鲫卵子控制异源精核发育的受精学机制

THE REGULATED DEVELOPMENT OF HETEROLOGOUSSPERM NUCLEUS BY EGGS OF NATURAL GYNOGENETIC SILVERCRUCIAN CARP(CARASSIUS AURATUS GIBELIO ) DURINGFERTILIZATION

作者对两性融合生殖鱼和雌核发育银鲫脱膜卵受精的精核发育进行了观察，并采用鱼类卵子无细胞系对以上两类卵质提取物体外诱导经Ｔｒｉｔｏｎ—Ｘ１００处理的精子及其发育进行了初步研究，结果表明在两性融合生殖型脱膜鱼卵中精核通过解凝最终形成原核，而在雌核发育的银鲫脱膜卵子中部分精核体积虽有一定程度的增加，但始终没有观察到原核的发育；在体外诱导实验中，经Ｔｒｉｔｏｎ—Ｘ１００处理的精子在两类卵质提取物中充分发育，都出现了类似体内原核的状态。该现象提示在银鲫卵质中存在有促使精核形成原核的因子，但在正常受精状态下，由于银鲫卵质促使精核核膜解体的功能的异常，使覆盖精子头部的核膜不能象在两性融合生殖受精卵子中进行崩解，精核进一步的原核发育受到抑制。另外，建立体外诱导系统的重要意义，在于它为研究雌核发育调控的分子学机制提供了一条有效途径。

The cytological behavior of sperm was observed after the sperm incorporated intodechorioned eggs of gynogenetic Silver crucian carp(Carassius gibelio)and bisexual fish(Carassius auratus red variety or Cy prinus carpio red variety).In bisexual dechorioned eggsthe sperm nuclei may undergo decondensing and developed into pronuclei.By contrast,although a few heterologous sperm nuclei became to some extent enlarged the pronuclei did notappear all.Furthermore,the established cell-free system from extraction of two types of eggswere employed to incubate the Triton-X100 treated sperm.The sperm nuclei in the two typesof extractions were fully developed, and then became the form of pronucleus,indicating thatthere are some factors responsible for sperm nucleus swelling and male pronucleus formationin gynogenetic Silver crucian carp eggs.However, when heterologous sperm entered intactgynogenetic eggs through micropyle,the nuclear envelope of sperm failed to breakdown dueto the abnormality of relative function in cytoplasm of the egg, and the further developmentwas thus inhibited. The significance of setting-up cell free system lies in that an efficient approach can be established to analyse the molecular mechanism by which the naturalgynogenesis was regulated during fertilization.