Fig. 4.

Cdc7 codepletion rescues fork slowing in Chk1-depleted cells. (A) Protein levels of Cdc7, Chk1, and β-Actin (loading control) in U2OS cells after 48 hours depletion with Cdc7, Chk1, Cdc7, and Chk1 or control siRNA. (B) Quantification of origin firing in Cdc7-, Chk1- or control-depleted cells. First label origins (green-red-green) are shown as percentage of all red (CldU) labeled tracks. (C) Distribution of replication fork speeds in Cdc7- or control-depleted cells. (D) Distribution of replication fork speeds in Chk1- or control-depleted cells. (E) Distribution of replication fork speeds in Cdc7- or Cdc7 and Chk1-depleted cells. (F) Average replication fork speeds in Cdc7-, Chk1-, or control-depleted cells. Means and standard deviation (S.D.) (bars) of three independent experiments are shown. Values marked with asterisks are significantly different (student’s t-test, * p < 0.05).