Department of Horticultural Science, University of Minnesota, St. Paul, MN, 55108, USA.
Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.
Nat Commun. 2018 Jun 18;9(1):2370. doi: 10.1038/s41467-018-04562-5.
Meiotic crossovers (COs) are not uniformly distributed across the genome. Factors affecting this phenomenon are not well understood. Although many species exhibit large differences in CO numbers between sexes, sex-specific aspects of CO landscape are particularly poorly elucidated. Here, we conduct high-resolution CO mapping in maize. Our results show that CO numbers as well as their overall distribution are similar in male and female meioses. There are, nevertheless, dissimilarities at local scale. Male and female COs differ in their locations relative to transcription start sites in gene promoters and chromatin marks, including nucleosome occupancy and tri-methylation of lysine 4 of histone H3 (H3K4me3). Our data suggest that sex-specific factors not only affect male-female CO number disparities but also cause fine differences in CO positions. Differences between male and female CO landscapes indicate that recombination has distinct implications for population structure and gene evolution in male and in female meioses.
减数分裂交叉（CO）在基因组中不是均匀分布的。影响这一现象的因素尚不清楚。尽管许多物种在雌雄个体间的 CO 数量上存在显著差异，但 CO 景观的性别特异性方面仍未得到充分阐明。在这里，我们在玉米中进行了高分辨率 CO 作图。我们的结果表明，CO 数量及其整体分布在雄性和雌性减数分裂中相似。然而，在局部尺度上存在差异。雄性和雌性 CO 在相对于基因启动子转录起始位点以及染色质标记（包括核小体占有率和组蛋白 H3 赖氨酸 4 的三甲基化（H3K4me3））的位置上存在差异。我们的数据表明，性别特异性因素不仅影响雌雄 CO 数量的差异，还导致 CO 位置的细微差异。雄性和雌性 CO 景观之间的差异表明，重组对雄性和雌性减数分裂中的群体结构和基因进化具有不同的影响。
