Intensive DNA Replication and Metabolism during the Lag Phase in Cyanobacteria
Fig 1
Growth and chromosome copy number during long-term culture.
(A) Growth curve of Synechococcus 7942TK after transfer to illuminated conditions, with a diagram showing the culture strategy. The stationary cultures were diluted to OD750 = 0.2 in fresh BG11 liquid medium. After 18 hr in the dark, cultures were transferred to light conditions (time 0). (B) DNA content profiles of Synechococcus 7942TK cells. Cells were harvested at each time point and analysed with flow cytometry. (C) Expression of RpoD1, DnaK2, and HA-tagged thymidine kinase (HA-TK). Synechococcus 7942TK cultures were harvested at the indicated times after transfer to liquid medium, and crude extracts were prepared. Samples containing 5 μg (RpoD1 and DnaK2) or 20 μg (HA-TK) of total protein were analysed with western blot using the appropriate antibodies.