Klar A J, Miglio L M
Cell. 1986 Aug 29;46(5):725-31. doi: 10.1016/0092-8674(86)90348-x.
Mitotic gene conversion and reciprocal recombination have recently been shown to be efficiently initiated by double-strand DNA breaks (DSBs) in both Saccharomyces cerevisiae and Schizosaccharomyces pombe. We tested whether DSBs could also initiate meiotic recombination at the mat1 locus in S. pombe. The mat1 switching-mechanism-generated DSB found in mitotically growing cells can be repaired without mat1 switching, since strains deleted for both donor loci (mat2-P and mat3-M) have the break but do not produce inviable cells. A (mat1-P X mat1-M) cross produced a high frequency (20%) of 3:1 gene conversions of mat1 in meiotic tetrads. Gene conversion events were associated with the recombination of flanking markers. Strains lacking the DSB failed to convert. Thus, the DSB at mat1 promotes efficient meiotic recombination in fission yeast.
最近研究表明，在酿酒酵母和粟酒裂殖酵母中，有丝分裂基因转换和相互重组能够由双链DNA断裂（DSB）有效引发。我们测试了DSB是否也能在粟酒裂殖酵母的mat1位点引发减数分裂重组。在有丝分裂生长的细胞中发现的由mat1转换机制产生的DSB，在没有mat1转换的情况下也能修复，因为缺失两个供体位点（mat2-P和mat3-M）的菌株有该断裂，但不会产生无法存活的细胞。（mat1-P×mat1-M）杂交在减数分裂四分体中产生了高频率（20%）的mat1 3:1基因转换。基因转换事件与侧翼标记的重组相关。缺乏DSB的菌株无法进行转换。因此，mat1处的DSB促进了裂殖酵母中高效的减数分裂重组。
