Coordination of DNA replication and cell division in Cyanobacteria Microcystis aeruginosa

Little is known about the cyanobacterial cell cycle. When either nalidixic acid or hydroxyurea was added to a synchronized culture of Microcystis aeruginosa to block DNA replication, cell division did not occur. Furthermore, transcription of the essential cell division gene, ftsZ was repressed. After DNA replication, ftsZ transcription, as well as cell division, was not affected by hydroxyl urea, suggesting that the DNA replication and cell division of M. aeruginosa are coordinated and that this coordination is partly controlled by ftsZ transcription depending on DNA replication.