Cyanobacteria's internal clock works independently of cell division timing

Deletion of the circadian clock gene, kaiC, abolishes rhythms of gene expression and cell division timing in the cyanobacterium Synechococcus elongatus.

• Overexpression of the ftsZ gene stops cell division but allows continued growth, resulting in filamentous cells.
• Nondividing filamentous cells maintain robust circadian rhythms of gene expression.
• The findings suggest that the cyanobacterial circadian timing system operates independently of cell division.
• Evidence indicates that the cyanobacterial circadian system is stable under various intracellular conditions.

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