Natural variation in meiotic recombination rate shapes introgression patterns in intraspecific hybrids between wild and domesticated barley
Natural variation in meiotic recombination rate shapes introgression patterns in intraspecific hybrids between wild and domesticated barley
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DOI：
10.1111/nph.16810
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发表时间：
2020-08-09
期刊：
影响因子：
9.4
通讯作者：
Pillen, Klaus
中科院分区：
文献类型：
--
作者：
Dreissig, Steven;Maurer, Andreas;Pillen, Klaus
减数分裂重组率在物种、种群和个体之间差异很大。同源染色体之间的遗传交换在进化中起着重要的作用，在基因渗入的情况下，通过打破有利和有害等位基因之间的连锁。因此，识别重组速率修饰因子对于理解和利用减数分裂重组速率的变化具有根本性和实际意义。我们调查了一个大型种内杂交群体（命名为HEB-25）来自驯化大麦和25个野生大麦种质之间的杂交重组率的变化。我们观察到的数量变化，总的交叉数与最大的1.4倍的差异，亚群和跨近着丝粒区域的重组率增加。减数分裂特异性α-kleisin cohesin亚基REC 8被确定为影响交换数和模式的候选基因。此外，我们量化了野生大麦的基因渗入模式，并揭示了本地和全基因组重组率的变化形状的基因渗入模式。识别等位基因变异inREC 8结合观察到的交叉模式的变化表明，染色质环是如何拴系到染色体轴的差异，从而减少跨着丝粒周围区域的交叉抑制。局部和全基因组重组率的变化正在形成基因渗入的模式，从而直接影响连锁拖拽的后果。
Meiotic recombination rates vary considerably between species, populations and individuals. The genetic exchange between homologous chromosomes plays a major role in evolution by breaking linkage between advantageous and deleterious alleles in the case of introgressions. Identifying recombination rate modifiers is thus of both fundamental and practical interest to understand and utilize variation in meiotic recombination rates. We investigated recombination rate variation in a large intraspecific hybrid population (named HEB-25) derived from a cross between domesticated barley and 25 wild barley accessions. We observed quantitative variation in total crossover number with a maximum of a 1.4-fold difference between subpopulations and increased recombination rates across pericentromeric regions. The meiosis-specific alpha-kleisin cohesin subunitREC8was identified as a candidate gene influencing crossover number and patterning. Furthermore, we quantified wild barley introgression patterns and revealed how local and genome-wide recombination rate variation shapes patterns of introgression. The identification of allelic variation inREC8in combination with the observed changes in crossover patterning suggest a difference in how chromatin loops are tethered to the chromosome axis, resulting in reduced crossover suppression across pericentromeric regions. Local and genome-wide recombination rate variation is shaping patterns of introgressions and thereby directly influences the consequences of linkage drag.