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.

中文翻译：

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高分辨率交叉作图揭示了玉米中雄性和雌性重组的异同。

减数分裂交换（COs）在基因组中分布不均匀。影响这种现象的因素尚不十分清楚。尽管许多物种在性别之间表现出很大的CO差异，但对CO格局的性别特定方面的了解却很少。在这里，我们在玉米中进行高分辨率CO定位。我们的结果表明，在雌性和雌性中，CO数量及其总体分布相似。但是，在地方范围内仍存在差异。相对于基因启动子和染色质标记的转录起始位点，男性和女性CO的位置有所不同，包括核小体占据和组蛋白H3（H3K4me3）赖氨酸4的三甲基化。我们的数据表明，性别特异性因素不仅会影响男女之间的CO差异，还会导致CO位置发生细微差异。