卵巢发育阻滞的人工三倍体鱼减数分裂染色体配对的光镜观察

采用界面铺张制片和硝酸银一步染色的方法，对人工三倍体水晶彩鲫卵巢发育阻滞型个体的减数分裂染色体配对进行了光镜观察。在分化有初级卵母细胞的卵巢发育阻滞型的三倍体鱼中，减数分裂粗线期细胞主要的由二价体和单价体组成，也见有少量三价体和其它多价体，其染色体成员数大多在９０左右；在不同细胞间，染色体的大小变化较大；配对联会过程中形成的配对叉和产生的特异蛋白在一些细胞中明显可见。文中讨论了三倍体染色体配对紊乱

LIGHT MICROSCOPE INVESTIGATION ON MEIOTIC CHROMOSOME PAIRING IN ARTIFICIAL TKIPLOID FISHS WITH B LOCKED OVARIES

Chromosome pairing was light microscopically investigated by applying surfacespreading technique in combination with 1-step silver staining method for the pa-chvtene chromosome of artificial triploid transparent colored crucian carp(Carassiusauratus transparent colored variety) with blocked ovaries.The triploid fishes wereproduced from hydrostatic pressure shock for fertilized eggs by inducing second po- lar body retention. The study was performed on the triploid females with blockedovaries,one of manv different types of females with various developing ovaries.Twosubtypes were distinguished according to the presence or absence of primary oocytes. Meiotic prophase cells were not observed in the triploid females without pri-mary oocytes.In the triplold females with blocked ovaries containing differentiatedprimary oocytes,the pachytene chromosomes were mainly composed of bivalents andunsynapsed univalents,and a few of trivalents and other multivalents were alsofound.There are about 90 chromosome elements including univalents,bivalents,tri-valents and other multivalents in the pachytene cells.The size of chromosomesamong diffrent pachytene cells was obviously various.The pairing forks and speci- fic synaptonemal proteins were clearly observed at some pairing and paired chromo-somes.The relationship between disturbed chromosome pairing and blocked oocytedeveloping has been briefly discussed. The investigation also suggested that the arti-ficial triploid fishes might be excellent materials for studying the mechanism ofchromosome pairing and synapsing.