Photorepair and Excision Repair Removal of UV-induced Pyrimidine Dimers and (6–4) Photoproducts in the Tail Fin of the Medaka, Oryzias latipes

Abstract

Medaka /UV / Oryzias latipes / Dna repair/fish Induction and repair of UV-B induced DNA damage in the tail fin of the Medaka, were examined immunohistochemicaly and by the enzyme-linked immunosorbent assay (ELISA). UV-induced DNA damage was detected only in the outermost layer of epithelial cells and did not differ in fishes having different degree of melanization. Both pyrimidine dimers and (6–4) photoproducts in the fin cells were removed by excision repair in the dark, the excision of (6–4) photoproducts being about twice as efficient as that of pyrimidine dimers. The rate of excision repair of UV-induced lesions in fin tissue was three to four times that in cultured Medaka cells, OL32. In the fin cells, reductions in the numbers of pyrimidine dimers and (6–4) photoproducts were seen after treatment with fluorescent light, whereas less reductions of pyrimidine dimers and no reductions of (6–4) photoproducts were observed in OL32 cells. © 1994, Journal of Radiation Research Editorial Committee. All rights reserved.