Figure 1.
Culturing and Sampling Wild-Type and cdk Mutant Cells.
Parallel cultures of wild type, cdka-1, and cdkb-1 were transferred to 33°C (restrictive temperature) at time zero.
(A) Schematic of the Chlamydomonas mitotic cell cycle in a light/dark-synchronized culture.
(B) Cell number and density by Coulter counter.
(C) DNA content by FACS. Wild-type cells replicate DNA between 14 and 16 h, as indicated by an increase in ploidy. Release of daughter cells is indicated by a return to 1C DNA content (arrow, newborn). cdka-1 cells have not initiated DNA replication by 18 h. cdkb-1 cells initiate replication at 16 h and arrest after one round of DNA replication (2C).
(D) Correlations of independent wild-type cDNA libraries from the same or different time points. R2 = variation explained by linear fit through the origin.