UV-induced unscheduled DNA synthesis in guinea pig skin melanocytes isolated in culture.
Pigmented melanocytes isolated in culture from the epidermis of guinea pig ears were used to study the unscheduled DNA synthesis (UDS) induced by ultraviolet (UV) irradiation at 254 nm. After irradiation, the cells were labeled for 6 hr with 3H-thymidine (3HTdR), fixed, dehydrated, and flat embedded in Epon. Radioautographs were made on serial 0.5-1 micrometer thick sections of the cultures in order to distinguish silver grains from pigment granules. Cells irradiated with 5, 10, or 50 joules (J) m-2 showed a 3HTdR uptake due to UDS, whereas their proliferative ability, measured by the 3HTdR uptake due to scheduled DNA synthesis, was very low. For the same UV doses, UDS was lower in melanocytes than in guinea pig fibroblasts and keratinocytes.
D000818:Animals; D002455:Cell Division; D004247:DNA / Q000096:biosynthesis; D004260:DNA Repair; D006168:Guinea Pigs; D008544:Melanocytes / Q000502:physiology / Q000528:radiation effects*; D012867:Skin / Q000166:cytology*; D014466:Ultraviolet Rays
D004247:DNA