Interhomolog bias during meiotic recombination: Meiotic functions promote a highly differentiated interhomolog-only pathway
Interhomolog bias during meiotic recombination: Meiotic functions promote a highly differentiated interhomolog-only pathway
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DOI：
10.1016/s0092-8674(00)80378-5
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发表时间：
1997-09-19
期刊：
影响因子：
64.5
通讯作者：
Kleckner, N
中科院分区：
文献类型：
--
作者：
Schwacha, A;Kleckner, N
减数分裂重组优先发生在同源非姐妹染色单体之间，而非姐妹染色单体之间，这与有丝分裂重组修复的偏向相反。我们研究了在缺乏减数分裂染色体蛋白Red1、减数分裂recA同源物Dmc1和/或有丝分裂recA同源物Rad51、Rad55和Rad57的酵母菌株中，同源染色体之间以及姐妹染色单体之间联合分子重组中间体（JMs）的形成。突变表型表明，大多数减数分裂重组是通过仅同源染色体间的途径发生的，沿着该途径，同源染色体间的偏向在双链断裂（DSB）形成之前或期间早期建立，然后在DSBs启动JM形成时得到加强。一个平行的、分化程度较低的途径产生姐妹染色单体间的事件，可能还有一些同源染色体间的事件。还揭示了有丝分裂recA同源物作为一个功能单位的协同作用、RED1的两种功能以及DMC1的同源染色体间相互作用功能。
Meiotic recombination occurs preferentially between homologous nonsister chromatids rather than between sisters, opposite to the bias of mitotic recombinational repair. We have examined formation of joint molecule recombination intermediates (JMs) between homologs and between sisters in yeast strains lacking the meiotic chromosomal protein Red1, the meiotic recA homolog Dmc1, and/or mitotic recA homolog(s), Rad51, Rad55, and Rad57. Mutant phenotypes imply that most meiotic recombination occurs via an interhomolog-only pathway along which interhomolog bias is established early, prior to or during double strand break (DSB) formation, and then enforced, just at the time when DSBs initiate JM formation. A parallel, less differentiated pathway yields intersister and, probably, a few interhomolog events. Coordinate action of mitotic recA homologs as one functional unit, two functions of RED1, and an interhomolog interaction function of DMC1 are also revealed.