Bodell W J, Banerjee M R
Nucleic Acids Res. 1976 Jul;3(7):1689-701. doi: 10.1093/nar/3.7.1689.
We have measured DNA repair in mouse satellite and main band DNA as resolved by Ag+-Cs2SO4 centrifugation in response to treatment with the alkylating agents, methyl methanesulfonate, and N-methyl-N-nitrosourea. We find that there is a statistically significant lower incorporation of 3H-Tdr into the satellite DNA as compared to the main band at varying periods after treatment with the alkylating agents. This suggests a reduced repair activity in the satellite DNA. We have measured the extent of binding of 14C-methyl methanesulfonate to the satellite, and main band DNA, and no difference in binding was observed, indicating that the reduced repair activity of satellite DNA is not due to a difference in binding of alkylating agents. We believe that the reduced incorporation of 3H-Tdr into satellite DNA may be due to its location in the condensed chromatin fraction.
我们通过用Ag⁺-Cs₂SO₄离心法分离小鼠卫星DNA和主带DNA，测量了它们在受到烷化剂甲磺酸甲酯和N-甲基-N-亚硝基脲处理后的DNA修复情况。我们发现，在用烷化剂处理后的不同时间段，与主带相比，³H-Tdr掺入卫星DNA的量在统计学上显著更低。这表明卫星DNA中的修复活性降低。我们测量了¹⁴C-甲磺酸甲酯与卫星DNA和主带DNA的结合程度，未观察到结合上的差异，这表明卫星DNA修复活性降低并非由于烷化剂结合的差异所致。我们认为，³H-Tdr掺入卫星DNA减少可能是由于其位于浓缩染色质组分中。
