Morphological analysis of nuclear separation and cell division during the life cycle of Escherichia coli
Morphological analysis of nuclear separation and cell division during the life cycle of Escherichia coli
复制标题
大肠杆菌生命周期中核分离和细胞分裂的形态学分析
DOI：
--
复制
发表时间：
1976
影响因子：
3.2
通讯作者：
C. Woldringh
中科院分区：
文献类型：
--
作者：
C. Woldringh
对平衡生长的大肠杆菌B/r进行了电子显微镜定量观察，其倍增时间(Tau)分别为32和60min。这种实验方法通过根据长度对连续切片的细胞进行分类，允许在细胞周期中对形态事件进行计时。核质的可见分离与库珀-赫尔姆施泰特模型预测的染色体复制终止时间一致。收缩细胞分裂过程的持续时间(10min)似乎与tau等于或小于60min的生长速度无关，但在生长较慢的细胞中，随着倍增时间的增加而增加。只有在细胞周期的最后一分钟才能观察到生理性分裂，即在细胞物理分离之前的分隔化。形态观察结果表明，tau=32min的细胞在分裂过程中继续伸长，而tau=60min的细胞则不能继续伸长。
Quantitative electron microscope observations were performed on Escherichia coli B/r after balanced growth with doubling times (tau) of 32 and 60 min. The experimental approach allowed the timing of morphological events during the cell cycle by classifying serially sectioned cells according to length. Visible separation of the nucleoplasm was found to coincide with the time of termination of chromosome replication as predicted by the Cooper-Helmstetter model. The duration of the process of constrictive cell division (10 min) appeared to be independent of the growth rate for tau equals 60 min or less but to increase with increase doubling time in more slowly growing cells. Physiological division, i.e., compartmentalization prior to physical separation of the cells, was only observed to occur in the last minute of the cell cycle. The morphological results indicate that cell elongation continues during the division process in cells with tau equals 32 min, but fails to continue in cells with tau equals 60 min.