Figure 1.

Dynamics of periodic transcripts in wild-type and cyclin mutant cells. Heat maps depicting mRNA levels of periodic genes are shown for a, wild-type and b, cyclin mutant cells. Each row in a and b represents data for the same gene (Supplementary Table 1). Transcript levels are expressed as log2-fold change vs. mean expression. Transcript levels at each point in the time series were mapped onto a cell cycle timeline³¹ (see Methods). The S and G2/M phases of the cyclin mutant timeline are shaded, indicating that by conventional definitions, cyclin mutant cells arrest at the G1/S-phase transition.