【摘要】 目的：分析太阳光与紫外线B（UVB）诱发基因突变的碱基特异性。方法：照射处理M13mp2噬菌体，选择突变株，用dye-Primer法测定lacZα基因区域的DNA序列。结果：太阳光和UVB照射均可引起突变率的明显增高，太阳光照射诱发突变的大部分（约80％）是鸟嘌呤的颠换，而UVB照射则诱发以C→T转换为主的突变（约50％）。结论：太阳光照射诱发基因突变的作用不完全决定于其中的UVB组分，其他组分也可能发挥一定的作用。更多还原

【Abstract】 Objective: To analyse the specificity of mutations induced by sunlight and ultraviolet B(UVB). Methods: M13mp2 phage was irradiated and mutants were selected, the DNA sequences inlacZ α region were determined with the dye-primer method. Results: Both sunlight and UVB caused anincrease in the mutation frequences significantly. Among the mutations induced by sunlight, about 80%were the transversion of guanine. For those induced by UVB, C-to-T transitions were predominant(about 50%). Conclusion: The mutagenic specificity of sunlight is determined not entirely hy UVBcomponent, but other components may also play some roles.更多还原