Fabre F, Roman H
Proc Natl Acad Sci U S A. 1977 Apr;74(4):1667-71. doi: 10.1073/pnas.74.4.1667.
Recombination between unirradiated chromosomes was induced by UV or x-ray irradiation of haploids followed by a mating with heteroallelic diploids of Saccharomyces cerevisiae. The selected event of intragenic recombination did not involve the participation of the irradiated chromosome and apparently was not caused by lesions introduced into the unirradiated chromosomes by some indirect process. The results favor the idea that recombination is repressed in the majority of vegetative cells and that one effect of radiation is the release of some factor(s) necessary for recombination. Consequently, the proportion of competent cells (i.e., cells able to recombine) in the population increases. This competent state seems necessary not only for the recombinational repair of radiation-induced lesions but also, since recombinants are produced in the absence of such lesions, for spontaneous recombination. Photoreactivation of the UV-irradiated haploids led to a decrease in the production of recombinants. Hence, lesions in the DNA appear to be responsible for the induction of the recombinational ability.
通过对单倍体进行紫外线或X射线照射，然后与酿酒酵母的异等位基因二倍体交配，诱导未受照射染色体之间发生重组。所选择的基因内重组事件不涉及受照射染色体的参与，显然也不是由某些间接过程引入未受照射染色体的损伤所导致的。这些结果支持这样一种观点，即重组在大多数营养细胞中受到抑制，而辐射的一个作用是释放重组所需的某些因子。因此，群体中有能力进行重组的细胞（即能够重组的细胞）比例增加。这种有能力的状态似乎不仅对于辐射诱导损伤的重组修复是必要的，而且由于在没有此类损伤的情况下也会产生重组体，所以对于自发重组也是必要的。紫外线照射的单倍体的光复活导致重组体产生减少。因此，DNA中的损伤似乎是重组能力诱导的原因。
