This is the first detailed analysis of the cell cycle
responses of melanocytes and keratinocytes in human
skin to UVR. We have observed increased BrdU
incorporation during the first 24h following irradiation,
suggesting that UVR is acting as a mitogen,
stimulation a rapid round of DNA synthesis. The
reduced BrdU labelling from 24 ± 48 h demonstrated
that cells did not re-enter S phase during this period.