【摘要】 应用透射电子显微镜观察了行雌核发育生殖的三倍体(体细胞具有150±染色体)和二倍体(2n=100)银鲫(Carassiusa uratus gibelio Bloch)的精子发生过程。两种倍性的雄性的精子发生过程中,染色体数和细胞核的体积均呈3:2的关系;而精巢的结构、细胞的形态和细胞器的构成均无明显的区别。其精子发生经历了精原细胞、初级精母细胞、次级精母细胞和精子细胞几个阶段,精子细胞再经过精子形成过程成为精子;三倍体银鲫的精子发生与二倍体一样能正常完成减数分裂,形成形态和功能正常的雄性配子。正常的精子发生过程证明,体细胞具有150±条染色体的黑龙江银鲫是已经初步完成二倍化的三倍体,雄性个体在生殖群体中起着重要的作用;推测黑龙江银鲫的二倍体实际可能是四倍体,则三倍体的黑龙江银鲫为偶倍性的六倍体,因此其减数分裂可以正常进行,同时又经历了一定程度的二倍化,所以雄性可育,且参与繁殖后代。更多还原

【Abstract】 The spermatogenesis of triploid and diploid crucian carp(Carassius auratus gibelio Bloch) was investigated by means of transmission electron microscopy.No significant differences were found in the structure of the spermary,cell morphology,and organelle composition during spermatogenesis in triploid and diploid males.The ratios of chromosome number and nuclear volume of triploid to those of the diploid were 3∶2.Our results showed that the spermatogenic process in triploid and diploid fish included the following stages:spermatogonium,primary spermatocyte,secondary spermatocyte,spermatid and sperm.In triploid fish,spermatogenesis and the biologic activity of spermatozoa were the same as those of the diploids.The triploid fish could produce normal mature spermatozoa after meiosis.The observation of normal spermatogenesis proved that crucian carp have the characteristic of the artioploidy,with 150± chromosomes in somatic cell.The males played a very important role in the population.It was predicted that the diploid crucian carp could be tetraploid;the males in the triploid were regarded as hexaploid,and they underwent diploidization.更多还原