DNA二重鎖切断修復機構と減数分裂期組換え
1998 年 38 巻 4 号 p. 156-161
詳細
1998 年 38 巻 4 号 p. 156-161
Genetic material suffers various spontaneous or environmental damages, among which DNA double-strand breaks (DSBs) are fatal to the cell since they bring to the loss of genetic information. Cells provide with two strategies to repair DSBs. One is through homologous recombination and the other through an end-to-end joining reaction. The former process is more accurate. RAD52 group genes of budding yeast are involved in these DSB repair processes. They are classified into two subgroups: one is composed of RAD51, 52, 54, 55 and 57 (RAD51 subgroup), which are involved in homologous recombination, and the other MRE11, RAD50 and XRS2 (MRE11 subgroup), which are involved in end-to-end joining.
The DSB repair system is required for the proper segregation of homologous chromosomes in the reductional division of meiosis. Meiotic recombination is initiated with the formation of DSBs, the ends of which are processed and provided for homology search. Two subgroup genes work at two distinct steps: MRE11 subgroup at DSB formation and RAD51 subgroup at homology search, respectively. In addition, other meiosis specific proteins are also required for initiation and completion of meiotic recombination, some of which are components of synaptonemal complex.
This review focuses on recent advances in the mechanism of DSB repair and its involvement in meiosis.
