Cis-effects on Meiotic Recombination Across Distinct a1-sh2 Intervals in a Common Zea Genetic Background Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY656756, AY656757, AY656758 and AY662984, AY662985, AY662986, AY662987.
Cis-effects on Meiotic Recombination Across Distinct a1-sh2 Intervals in a Common Zea Genetic Background Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY656756, AY656757, AY656758 and AY662984, AY662985, AY662986, AY662987.
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DOI：
10.1534/genetics.104.034454
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发表时间：
2005-08
期刊：
影响因子：
3.3
通讯作者：
Hong Yao;P. Schnable
中科院分区：
文献类型：
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作者：
Hong Yao;P. Schnable
在三个具有不同结构的大刍动物A1 - Sh2单倍型（来自Z. mays spp. mexicana Chalco， Z. mays spp. parviglumis和Z. luxians）和一个普通玉米A1::rdt - Sh2单倍型的近等基因种群中，A1 - Sh2区间的遗传距离变化了3倍。在每个单倍型中，85%的重组事件发生在约130-kb a1-sh2区间的近10%。即便如此，在单倍型的亚区间内，重组断点的分布仍存在显著差异。先前检测到的三个重组热点在三种大刍动物单倍型中至少有一种被检测到，其中两个热点在至少一种大刍动物单倍型中未被检测到。此外，在两个大刍草单倍型中发现了新的热点。由于三个种群的近等基因性质，观察到的重组事件分布的变化是顺式修饰的结果。虽然通常与每百万碱基的重组率呈负相关，但序列多态性的水平并不能完全解释重组断点的非随机分布。这项研究还表明，在考虑基因是否处于选择状态时，对连锁不平衡的估计必须谨慎解释。
Genetic distances across the a1-sh2 interval varied threefold in three near-isogenic stocks that carry structurally distinct teosinte A1 Sh2 haplotypes (from Z. mays spp. mexicana Chalco, Z. mays spp. parviglumis, and Z. luxurians) and a common maize a1::rdt sh2 haplotype. In each haplotype >85% of recombination events resolved in the proximal 10% of the ∼130-kb a1-sh2 interval. Even so, significant differences in the distributions of recombination breakpoints were observed across subintervals among haplotypes. Each of the three previously detected recombination hot spots was detected in at least one of the three teosinte haplotypes and two of these hot spots were not detected in at least one teosinte haplotype. Moreover, novel hot spots were detected in two teosinte haplotypes. Due to the near-isogenic nature of the three stocks, the observed variation in the distribution of recombination events is the consequence of cis-modifications. Although generally negatively correlated with rates of recombination per megabase, levels of sequence polymorphisms do not fully account for the nonrandom distribution of recombination breakpoints. This study also suggests that estimates of linkage disequilibrium must be interpreted with caution when considering whether a gene has been under selection.