Circadian gating of cell division in cyanobacteria growing with average doubling times of less than 24 hours
Circadian gating of cell division in cyanobacteria growing with average doubling times of less than 24 hours
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DOI：
10.1073/pnas.93.19.10183
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发表时间：
1996-09-17
影响因子：
11.1
通讯作者：
Johnson, CH
中科院分区：
文献类型：
--
作者：
Mori, T;Binder, B;Johnson, CH
为了确定原核蓝细菌聚球藻PCC 7942中的昼夜节律振荡器是否调节快速生长培养物中细胞分裂的时间，我们测量了连续稀释以保持大致相等的细胞密度的培养物中的细胞分裂速率、DNA含量、细胞大小和基因表达（通过PpsbAI：：luxAB报告基因的发光来监测）。我们发现，以每10小时一次的速度分裂的群体表现出细胞分裂的昼夜节律门控，因为细胞分裂减缓或停止的阶段具有昼夜节律周期性。这些数据清楚地表明，聚球藻细胞以比每24小时一次快得多的倍增时间生长，但仍然表达了细胞分裂和基因表达的强大昼夜节律。显然，聚球藻细胞能够同时维持两个表达显着不同时期的计时回路。
To ascertain whether the circadian oscillator in the prokaryotic cyanobacterium Synechococcus PCC 7942 regulates the timing of cell division in rapidly growing cultures, we measured the rate of cell division, DNA content, cell size, and gene expression (monitored by luminescence of the PpsbAI::luxAB reporter) in cultures that were continuously diluted to maintain an approximately equal cell density. We found that populations dividing at rates as rapid as once per 10 h manifest circadian gating of cell division, since phases in which cell division slows or stops recur with a circadian periodicity. The data clearly show that Synechococcus cells growing with doubling times that are considerably faster than once per 24 h nonetheless express robust circadian rhythms of cell division and gene expression. Apparently Synechococcus cells are able to simultaneously sustain two timing circuits that express significantly different periods.