Boundy-Mills K L, Livingston D M
Department of Biochemistry, University of Minnesota, Minneapolis 55455.
Genetics. 1993 Jan;133(1):39-49. doi: 10.1093/genetics/133.1.39.
A nonsense allele of the yeast RAD52 gene, rad52-327, which expresses the N-terminal 65% of the protein was compared to two missense alleles, rad52-1 and rad52-2, and to a deletion allele. While the rad52-1 and the deletion mutants have severe defects in DNA repair, recombination and sporulation, the rad52-327 and rad52-2 mutants retain either partial or complete capabilities in repair and recombination. These two mutants behave similarly in most tests of repair and recombination during mitotic growth. One difference between these two alleles is that a homozygous rad52-2 diploid fails to sporulate, whereas the homozygous rad52-327 diploid sporulates weakly. The low level of sporulation by the rad52-327 diploid is accompanied by a low percentage of spore viability. Among these viable spores the frequency of crossing over for markers along chromosome VII is the same as that found in wild-type spores. rad52-327 complements rad52-2 for repair and sporulation. Weaker intragenic complementation occurs between rad52-327 and rad52-1.
酵母RAD52基因的一个无义等位基因rad52 - 327，它表达该蛋白质N端65%的部分，与两个错义等位基因rad52 - 1和rad52 - 2以及一个缺失等位基因进行了比较。虽然rad52 - 1和缺失突变体在DNA修复、重组和孢子形成方面有严重缺陷，但rad52 - 327和rad52 - 2突变体在修复和重组方面保留了部分或全部能力。在有丝分裂生长期间的大多数修复和重组测试中，这两个突变体表现相似。这两个等位基因之间的一个差异是，纯合的rad52 - 2二倍体不能形成孢子，而纯合的rad52 - 327二倍体形成孢子的能力较弱。rad52 - 327二倍体形成孢子的水平较低，同时孢子活力的百分比也较低。在这些有活力的孢子中，沿着染色体VII的标记发生交换的频率与野生型孢子中的频率相同。rad52 - 327在修复和孢子形成方面能互补rad52 - 2。rad52 - 327和rad52 - 1之间发生较弱的基因内互补。
