ROLES FOR 2 RECA HOMOLOGS IN PROMOTING MEIOTIC CHROMOSOME SYNAPSIS
ROLES FOR 2 RECA HOMOLOGS IN PROMOTING MEIOTIC CHROMOSOME SYNAPSIS
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DOI：
10.1101/gad.9.21.2684
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发表时间：
1995-11-01
影响因子：
10.5
通讯作者：
ROEDER, GS
中科院分区：
文献类型：
--
作者：
ROCKMILL, B;SYM, M;ROEDER, GS
先前的研究表明，酿酒酵母的RAD 51和DMC 1基因编码大肠杆菌RecA链交换酶的同源物。结果表明，dmc 1和rad51突变体几乎完成了染色体联会，但联会复合体的形成比野生型明显延迟。在zip1突变体中，染色体同源配对，但不突触，并且每对染色体的蛋白质骨架（轴向元件）在本文中称为轴向缔合的几个位点处彼此紧密连接。dmc 1 zip1和rad51 zip1双突变体组装轴向元件，没有明显的关联，表明Dmc 1和Rad51蛋白是建立或稳定轴向关联所必需的。我们认为，轴向联合有助于促进减数分裂染色体联会，而这些联合的缺失是dmc 1和rad 51菌株中观察到的延迟和低效联会的主要原因。在单倍体酵母的减数分裂过程中，染色体联会发生在非同源染色体片段之间。在zip1单倍体中，轴向关联不明显，表明这些关联依赖于同源序列之间的相互作用。
Previous studies have shown that the RAD51 and DMC1 genes of Saccharomyces cerevisiae encode homologs of the Escherichia coli RecA strand exchange enzyme. Results presented here demonstrate that the dmc1 and rad51 mutants undergo nearly complete chromosome synapsis, but synaptonemal complex formation is delayed substantially compared with wild type. In the zip1 mutant, chromosomes are paired homologously, but not synapsed, and the protein backbones (axial elements) of each pair of chromosomes are connected intimately to each other at a few sites referred to herein as axial associations. dmc1 zip1 and rad51 zip1 double mutants assemble axial elements that are not obviously associated, demonstrating that the Dmc1 and Rad51 proteins are required to establish or stabilize axial associations. We propose that axial associations serve to promote meiotic chromosome synapsis and that the absence of these associations accounts far the delayed and inefficient synapsis observed in dmc1 and rad51 strains. During meiosis in haploid yeast, chromosome synapsis takes place between nonhomologous chromosome segments. In a zip1 haploid, axial associations are not apparent, suggesting that these associations depend on interactions between homologous sequences.