Sekelsky J J, McKim K S, Chin G M, Hawley R S
Section of Molecular and Cellular Biology, University of California, Davis 95616, USA.
Genetics. 1995 Oct;141(2):619-27. doi: 10.1093/genetics/141.2.619.
Meiotic recombination and DNA repair are mediated by overlapping sets of genes. In the yeast Saccharomyces cerevisiae, many genes required to repair DNA double-strand breaks are also required for meiotic recombination. In contrast, mutations in genes required for nucleotide excision repair (NER) have no detectable effects on meiotic recombination in S. cerevisiae. The Drosophila melanogaster mei-9 gene is unique among known recombination genes in that it is required for both meiotic recombination and NER. We have analyzed the mei-9 gene at the molecular level and found that it encodes a homologue of the S. cerevisiae excision repair protein Rad1, the probable homologue of mammalian XPF/ERCC4. Hence, the predominant process of meiotic recombination in Drosophila proceeds through a pathway that is at least partially distinct from that of S. cerevisiae, in that it requires an NER protein. The biochemical properties of the Rad1 protein allow us to explain the observation that mei-9 mutants suppress reciprocal exchange without suppressing the frequency of gene conversion.
减数分裂重组和DNA修复由重叠的基因集介导。在酿酒酵母中，修复DNA双链断裂所需的许多基因也是减数分裂重组所必需的。相比之下，核苷酸切除修复（NER）所需基因的突变对酿酒酵母的减数分裂重组没有可检测到的影响。黑腹果蝇的mei-9基因在已知的重组基因中是独特的，因为它对于减数分裂重组和NER都是必需的。我们已经在分子水平上分析了mei-9基因，发现它编码酿酒酵母切除修复蛋白Rad1的同源物，可能是哺乳动物XPF/ERCC4的同源物。因此，果蝇减数分裂重组的主要过程通过至少部分不同于酿酒酵母的途径进行，因为它需要一种NER蛋白。Rad1蛋白的生化特性使我们能够解释mei-9突变体抑制相互交换而不抑制基因转换频率的观察结果。
