Kolodkin A L, Klar A J, Stahl F W
Cell. 1986 Aug 29;46(5):733-40. doi: 10.1016/0092-8674(86)90349-1.
We investigated the effects of double-strand breaks on meiotic recombination in yeast. A double-strand break was introduced at the MATa locus by sporulation of a MAT alpha inc/MATa diploid under inducing conditions for the HO-encoded endonuclease; 14% of the resulting tetrads had undergone 4 alpha:0a conversion. Conversion at MAT was associated with co-conversion of a closely linked marker and an increased recombination frequency for flanking markers. We also studied the sporulation products of a diploid heterozygous at the HIS4 locus for an insertion of a 100 bp fragment of MATa containing the HO endonuclease cut site. Under inducing conditions, a significant number of tetrads were formed that had undergone gene conversions in favor of the HIS4+ allele. Although double-strand breaks can initiate meiotic recombination in yeast, the data suggest that they do not normally do so.
我们研究了双链断裂对酵母减数分裂重组的影响。在诱导HO编码的内切核酸酶的条件下，通过MATαinc/MATa二倍体的孢子形成，在MATa位点引入双链断裂；14%的所得四分体发生了4α:0a转换。MAT位点的转换与紧密连锁标记的共转换以及侧翼标记的重组频率增加相关。我们还研究了在HIS4位点杂合的二倍体的孢子形成产物，该二倍体插入了包含HO内切核酸酶切割位点的100bp MATa片段。在诱导条件下，形成了大量发生有利于HIS4+等位基因的基因转换的四分体。虽然双链断裂可以启动酵母中的减数分裂重组，但数据表明它们通常不会这样做。
