摘要
以草鱼ZC7901细胞株为材料,观察鱼类细胞从间期染色质到中期染色体的包装过程。主要通过:(1)分裂期与间期细胞融合,诱导染色体早熟凝集;(2)染色体“伸长”处理;(3)培养细胞的低渗处理;(4)染色质铺展等方法,制作染色体标本,进行扫描和透射电镜观察。 观察表明,鱼类染色质的基本结构与哺乳类细胞相同,也是直径约10nm的核丝(Nucleofilament)。染色体的色装有两种形式:一种是多级螺旋化形成直径约300nm的染色单体,再经过一次绞合,形成约600nm的染色体;另一种是从30nm或60nm的螺线管直接折叠交联包装,其间也伴有部分不规则螺旋的纤丝形成染色体。本文认为:前一种螺旋化是草鱼染色体的正常包装,后一种折叠交联是染色体的快速早熟包装。
The cell strain ZC-7901 of Grass Carp snout tissue was adopted for the research of packing from basic chromatin fibres to chromosomes. In studying of the subject, four methods were used: the induction of premature chromosome condensation in interphase nuclei by fusing with metaphase cell; the 'elongation' of chromosomes; the moderate hypo-osmosis of culture cells and spreading chromatin. Scanning and transmission electron microscopes were used to investigate the prepared specimens.
The observations showed that the basic structure of fish chromatin was the same as that of mammalians, which was the nucleofilament of 10 nm in diameter. There were two patterns from the chromatin packing into the chromosome: one was the multiple spiralization from the basic fibre into the chromatid of about 300 nm in diameter, and then to the sister chromatids which twisted into the chromosome; the other one was the directly fold coupling from 30 nm or 60 nm solenoids into the chromosome in which the partial helical irregular fibres coexisted.
It was suggested that the spiralization was the normal packing pattern of the chromosomes of Grass Carp, and the fold coupling was the rapid and premature condensation.
关键词
草鱼
染色体
包装
鱼纲
Grass Carp, Chromosome packing, Premature chromosome condensation
