Ley R D, Applegate L A, Freeman S E
Division of Biomedical Research, Lovelace Medical Foundation, Albuquerque, NM 87108.
Mutat Res. 1988 Jul;194(1):49-55. doi: 10.1016/0167-8817(88)90055-7.
The induction and photorepair of pyrimidine dimers in DNA have been measured in the ultraviolet-irradiated, corneal epithelium of the marsupial, Monodelphis domestica, using damage-specific nucleases from Micrococcus luteus in conjunction with agarose gel electrophoresis. We observed that FS-40 sunlamps (280-400 nm) induced 7.2 +/- 1.0 X 10(-5) pyrimidine dimers per kilobase (kb) of DNA per J/m2. Following 100 J/m2, 50% and greater than 90% of the dimers were photorepaired during a 10- and 30-min exposure to photoreactivating light (320-400 nm), respectively. In addition, approximately 70% and approximately 60% of the dimers induced by 300 and 500 J/m2, respectively, were repaired by a 60-min exposure to photoreactivating light. The capacity of the corneal epithelium of M. domestica to photorepair pyrimidine dimers identifies this animal as a potentially useful model with which to determine whether pyrimidine dimers are involved in pathological changes of the irradiated eye.
利用藤黄微球菌的损伤特异性核酸酶结合琼脂糖凝胶电泳，对有袋动物短尾矮袋鼠经紫外线照射后的角膜上皮细胞DNA中嘧啶二聚体的诱导和光修复情况进行了测定。我们观察到，FS - 40太阳灯（280 - 400纳米）每焦耳每平方米可诱导每千碱基（kb）DNA产生7.2±1.0×10⁻⁵个嘧啶二聚体。在100焦耳每平方米照射后，分别在10分钟和30分钟的光激活光（320 - 400纳米）照射下，50%及超过90%的二聚体被光修复。此外，经60分钟的光激活光照射后，分别由300焦耳每平方米和500焦耳每平方米诱导产生的二聚体中，约70%和约60%被修复。短尾矮袋鼠角膜上皮细胞光修复嘧啶二聚体的能力表明，这种动物是一种潜在的有用模型，可用于确定嘧啶二聚体是否参与受照射眼睛的病理变化。
