Effects of DNA repair on homologous and non-homologous recombination

对大约40种不同的脉孢菌DNA修复突变体进行了遗传学特征分析，并对它们对诱变剂的敏感性进行了广泛的测试。根据这些结果，我们分离了5到6个候选的重组修复缺陷突变体，并测试了它们将一个质粒pMTR整合到基因组DNA的能力。突变体mei-3，mei-2，uvs-6，mus-25的同源重组频率很低。我们尝试用同胞选择的方法克隆这些基因。克隆的MEI-3与E.ColirecA和S.cerevisiae RAD51有很高的相似性。MUS-25基因是酿酒酵母RAD54的同源基因。它们是酵母中重组修复的成员。因此，该基因群包括mei-3和mus-25，可能在粗脉孢子菌的同源重组系统中发挥作用。

About 40 different Neurospora DNA repair mutants were characterized genetically and their sensitivities to mutagens were extensively tested. From those results, we isolated 5 to 6 as candidates of recombinational repair-deficient mutants and tested their abilities of integration of a plasmid pMTR to genome DNA.Mutants, mei-3, mei-2, uvs-6, mus-25 showed very low homologous recombination frequencies. We tried to clone those genes using sib selection method. Cloned mei-3 showed that it has high similarity to E.coli recA and S.cerevisiae RAd51. Gene mus-25 was a homolog of S.cerevisiae RAD54. They are member of recombinational repair in yeast. Therefore, it seems that this group including mei-3 and mus-25, functions in homologous recombination system in Neurospora crassa.