Ultraviolet radiation-induced lethality and repair of pyrimidine dimers in fish embryos.
Pimephales promelas (fathead minnow) embryos were used to show a correlation between induction of pyrimidine dimers in DNA and embryo death. Embryo killing was measured by a lack of heart-beat and blood circulation at 48 h post-ultraviolet radiation (UVR). When the embryos were exposed to various doses of UVR from a FS-40 sunlamp followed by exposure to photoreactivating light (PRL) (320-400 nm), the number of pyrimidine dimers decreased significantly. The photorepair of dimers was accompanied by a substantial increase in embryo survival. When embryo killing was examined as a function of the number of dimers present, dimers were identified as a major lesion involved in UVR-induced killing in these fish embryos. This in vivo study on photoreactivation treatment of fish embryos shows a direct association between UVR-induced pyrimidine dimers and embryo killing. In addition, when embryos were held in the dark for 9 h after UVR, 50% of the dimers were removed by excision repair.
Applegate
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LA
Division of Biomedical Research, Lovelace Medical Foundation, Albuquerque, NM 87108.
Ley
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RD
D000818:Animals; D003530:Cyprinidae / Q000196:embryology / Q000235:genetics / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000528:radiation effects*; D011740:Pyrimidine Dimers / Q000378:metabolism*; D014466:Ultraviolet Rays / Q000009:adverse effects
D011740:Pyrimidine Dimers