Crossover homeostasis in yeast meiosis
Crossover homeostasis in yeast meiosis
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DOI：
10.1016/j.cell.2006.05.044
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发表时间：
2006-07-28
期刊：
影响因子：
64.5
通讯作者：
Keeney, Scott
中科院分区：
文献类型：
--
作者：
Martini, Emmanuelle;Diaz, Robert L.;Keeney, Scott
同源重组产生的杂交促进了减数分裂中染色体的准确分离，并受到控制，使每对染色体至少有一种形式，并且多个杂交间隔很大。重组开始于Spo11蛋白造成的大量双链断裂。因此，交叉控制涉及这样一种决策，即一些中断提供交叉，而另一些则遵循主要的非交叉路径(S)。为了理解这一决定，我们研究了酵母sp11亚型中断裂减少时的重组。我们发现，交叉水平往往是以牺牲非交叉为代价的，而且基因组基因座在这种“交叉稳态”的表达上有所不同。这些发现定义了一种以前未被怀疑的交叉控制表现，即交叉/非交叉比率可以改变以维持交叉。我们的结果区分了现有的交叉控制模型，并支持这样的假设，即专有的交叉是与交叉干扰有关的遗传编程事件。
Crossovers produced by homologous recombination promote accurate chromosome segregation in meiosis and are controlled such that at least one forms per chromosome pair and multiple crossovers are widely spaced. Recombination initiates with an excess number of double-strand breaks made by Spo11 protein. Thus, crossover control involves a decision by which some breaks give crossovers while others follow a predominantly noncrossover pathway(s). To understand this decision, we examined recombination when breaks are reduced in yeast spo11 hypomorphs. We find that crossover levels tend to be maintained at the expense of noncrossovers and that genomic loci differ in expression of this "crossover homeostasis." These findings define a previously unsuspected manifestation of crossover control, i.e., that the crossover/noncrossover ratio can change to maintain crossovers. Our results distinguish between existing models of crossover control and support the hypothesis that an obligate crossover is a genetically programmed event tied to crossover interference.