Daly M J, Minton K W
Department of Pathology, F. E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA.
J Bacteriol. 1995 Oct;177(19):5495-505. doi: 10.1128/jb.177.19.5495-5505.1995.
Deinococcus radiodurans and other members of the genus Deinococcus are remarkable for their extreme resistance to ionizing radiation and many other agents that damage DNA. We have recently shown that recombinational processes participate in interplasmidic repair following in vivo irradiation. We now present direct studies on interchromosomal recombination among chromosomes irradiated in vivo during stationary phase (four chromosomes per cell). Following an exposure to 1.75 Mrad (the dose required to achieve a survival of 37%, which degrades the cells' four chromosomes into about 500 fragments), we determined that there may be as many as 175 crossovers per chromosome (700 crossovers per nucleoid) undergoing repair. In addition, these studies suggest that many of the crossovers occurring during repair are nonreciprocal.
耐辐射球菌及其他耐辐射球菌属成员以其对电离辐射和许多其他损伤DNA的因子具有极强的抗性而著称。我们最近表明，重组过程参与体内照射后的质粒间修复。我们现在展示了对静止期体内照射的染色体（每个细胞四条染色体）间染色体重组的直接研究。在暴露于1.75兆拉德（达到37%存活率所需的剂量，该剂量将细胞的四条染色体降解为约500个片段）后，我们确定每条进行修复的染色体可能有多达175次交换（每个类核有700次交换）。此外，这些研究表明修复过程中发生的许多交换是非相互的。
