【摘要】 以野生型大肠菌ＣＳＨ５０及ｍｕｔＭ缺陷的大肠菌ＭＦ６７为宿主，观察了太阳光对Ｍ１３ｍｐ~２噬菌体单链ＤＮＡ ｌａｃＺα基因区域的致突变性．结果显示，太阳光照射引起噬菌体ｌａｃＺα基因区域的突变，在ｍｕｔＭ缺陷的宿主中更为明显；０．２５ｍｏｌ／Ｌ的甘露醇可以部分拮抗太阳光的致突变作用．以ＥＳＲ自旋捕捉法检测了太阳光、长波紫外线（ＵＶＡ）及中波紫外线（ＵＶＢ）照射Ｍ１３ｍｐ~２噬菌体样品中的自由基，结果还显示，太阳光和ＵＶＡ照射可引起羟自由基的产生，而ＵＴＢ照射则没有明显的自由基信号产生说明太阳光致突变作用与ＤＮＡ氧化损伤有关，羟自由基在其中发挥一定的作用更多还原

【Abstract】 The mutagenesis by sunlight on the lacZα region of M13mp~2 phage was observed in wild-type host (E.coli CSH50) and mutM-deficient one (E.coli MF67). The results showed that the mutation frequencies induced by sunlight were significantly higher in MF67 than in CSH50. The mutagenesis by sunlight was inhibited in part by 0.25mol/L of mannitol. Free radicals in M13mp~2 phage irradiated by sunlight, UVA and UVB were determined with ESR spin trapping method. There were hydroxyl free radicals determined in the samples irradiated by sunlight and UVA, but nothing in those by UVB.These results indicate that the mutagenesis by sunlight is relative with oxidative damage of DNA and hydroxyl free radicals are involved in it.更多还原