Umehara Senkei, Inoue Ippei, Wakamoto Yuichi, Yasuda Kenji
Department of Biomedical Information, Division of Biosystems, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Tokyo 101-0062, Japan.
Biophys J. 2007 Aug 1;93(3):1061-7. doi: 10.1529/biophysj.106.098061. Epub 2007 May 11.
We examined the origin of individuality of two daughter cells born from an isolated single Escherichia coli mother cell during its cell division process by monitoring the change in its swimming behavior and tumbling frequency using an on-chip single-cell cultivation system. By keeping the isolated condition of an observed single cell, we compared its growth and swimming property within a generation and over up to seven generations. It revealed that running speed decreased as cell length smoothly increased within each generation, whereas tumbling frequency fluctuated among generations. Also found was an extraordinary tumbling mode characterized by the prolonged duration of pausing in predivisional cells after cell constriction. The observed prolonged pausing may imply the coexistence of two distinct control systems in a predivisional cell, indicating that individuality of daughter cells emerges after a mother cell initiates constriction and before it gets physically separated into two new cell bodies.
我们通过使用芯片上的单细胞培养系统监测其游动行为和翻滚频率的变化，研究了单个分离的大肠杆菌母细胞在细胞分裂过程中产生的两个子细胞的个体性起源。通过保持观察到的单个细胞的分离状态，我们比较了其在一代内以及多达七代中的生长和游动特性。结果表明，在每一代中，随着细胞长度的平稳增加，游动速度下降，而翻滚频率在各代之间波动。还发现了一种特殊的翻滚模式，其特征是细胞缢缩后分裂前细胞的暂停持续时间延长。观察到的延长暂停可能意味着分裂前细胞中存在两种不同的控制系统，这表明子细胞的个体性在母细胞开始缢缩后且在其物理上分离成两个新细胞体之前就已出现。
