Inactivation of origins firing in response to UVA-induced ROS in Chk1-deficient MRC5Vi cells.

Asynchronous MRC5Vi cells were transfected with siCtr or siChk1 and exposed to 160 kJ/m2 of UVA in MEMi 48h post transfection. IdU and CldU were then sequentially added to the medium 4 h post UVA. The forks density is defined as the ratio between the number of CldU-IdU-CldU signals (red-green-red signals) and the length of replicated DNA. The percentage of cells in S-phase at the labeling time was determined by flow cytometry and was found to be 47%. The forks velocity was recorded only using the CldU tracks length. The data correspond to one experiment.Inactivation of origins firing in response to UVA-induced ROS in Chk1-deficient MRC5Vi cells.