Multiple sideways transfers of the daily rhythm gene group in filamentous nitrogen-fixing cyanobacteria

Phylogenetic analysis reveals that the kaiBC gene cluster in filamentous cyanobacteria has undergone multiple lateral transfers during evolution.

• Cyanobacteria possess a circadian rhythm regulated by the genes kaiA, kaiB, and kaiC.
• Lateral gene transfers of the kaiBC cluster appear to have been frequent among filamentous cyanobacteria.
• The lateral transfers observed occurred at various points in the evolutionary history of these species.
• These findings may indicate that the transfers are associated with adaptive advantages in cyanobacteria.

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