Department of Biophysics and Medical Physics, University of California, 94720, Berkeley, CA, USA.
Curr Genet. 1983 Apr;7(2):93-100. doi: 10.1007/BF00365632.
Plasmids that complement the yeast mutations rad50-1, rad51-1, rad54-3 and rad55-3 were obtained by transforming strains that carried a leu2 marker and the particular rad mutation, with YEp13 plasmids containing near random yeast DNA inserts. Integration of these plasmids or of fragments of these plasmids was accomplished. Genetic studies using the integrants established the presence of the genes RAD51, RAD54 and RAD55 in the respective plasmids. However, a BamHI subclone of the rad50-1 complementing plasmid failed to integrate at the RAD50 locus, indicating that no homology exists between this fragment and the RAD50 gene.A BamHI fragment from the RAD54 plasmid was shown to be internal to the RAD54 gene: its integration within a wild type copy of RAD54 causes the cell to become Rad(-); its excision is X-ray inducible and restores the Rad(+) phenotype. Since cells bearing a disrupted copy of RAD54 are able to survive, we conclude that this gene is not essential.
通过转化携带亮氨酸标记和特定 rad 突变的菌株，并使用含有近随机酵母 DNA 插入的 YEp13 质粒，获得了补充酵母突变 rad50-1、rad51-1、rad54-3 和 rad55-3 的质粒。这些质粒或这些质粒的片段的整合是通过遗传研究使用整合子完成的。使用整合子的研究确立了 RAD51、RAD54 和 RAD55 基因在各自质粒中的存在。然而，rad50-1 互补质粒的 BamHI 亚克隆未能整合到 RAD50 基因座上，表明该片段与 RAD50 基因之间不存在同源性。RAD54 质粒的 BamHI 片段被证明位于 RAD54 基因内部：其在野生型 RAD54 拷贝内的整合使细胞成为 Rad(-)；其切除是 X 射线诱导的，并恢复 Rad(+)表型。由于携带破坏的 RAD54 拷贝的细胞能够存活，我们得出结论，该基因不是必需的。
