Figure 1. cdc22 mRNA is up regulated during an HU-induced replication checkpoint and an MMS-induced S-phase DNA damage checkpoint, but not during an IR-induced G2 DNA damage checkpoint.

Wild type (yFS625) cells were synchronized in early G2 by centrifugal elutriation, treated with 10 mM HU, 0.015% MMS or 200 grays of ionizing radiation and followed through a synchronous cell cycle. Samples were taken every 20 minutes for RNA isolation and visual inspection of septation. A) Septation index of treated cultures and untreated controls. B) cdc22 mRNA level in treated cultures and untreated controls, normalized to adh1 levels and to the 20 minute timepoint of the untreated sample. C) Northern blots quantitated in B. Blots were probed with cdc22, stripped and reprobed with adh1 as a loading control.