Single gametophyte sequencing reveals that crossover events differ between sexes in maize

First author: Cheng Luo; Affiliations: Huazhong Agricultural University (华中农业大学): Wuhan, China

Corresponding author: Jianbing Yan 

Meiotic crossover (CO) plays a key role in producing gametophytes and generating genetic variation. The patterns of CO production differ inter- and intra-species, as well as between sexes. However, sex-specific patterns of CO production have not been accurately profiled independently of genetic backgrounds in maize. Here, we develop a method to isolate single female gametophyte for genomes sequencing in maize. We show that more COs are observed in male (19.3 per microspore) than in female (12.4 per embryo sac). Based on Beam-Film model, the more designated class I and II COs are identified in male than in female. In addition, CO maturation inefficiency (CMI) is detected in some genetic backgrounds, suggesting that maize may be an ideal model for dissecting CMI. This research provides insights toward understanding the molecular mechanism of CO production between sexes and may help to improve maize breeding efficiency through paternal selection.

减数分裂染色体交换CO在产生配子体和生成遗传变异方面发挥重要作用。种内和种间产生的CO模式大有不同，不同性别之间也一样具有差异。然而，独立于遗传背景之外的性别特异性CO模式还从未在玉米中有过报道。本文，作者针对玉米开发了一套分离单个雌配子体的方法用于基因组测序。作者发现，雄性中所观察到的CO数目为每个小孢子平均19.3次，这要多于雌性中所观察到的每个胚囊平均12.4次的数目。基于Beam-Film模型，雄性中划分为第I类和第II类的CO要比雌性中的多。另外，作者在某些遗传背景的玉米中鉴定到了染色体交换成熟无效CMI，说明玉米可能是解析CMI的理想模式植物。本研究为理解植物不同性别间染色体交换的分子机制提供了新的视野，同时将有助于通过父本选择提升玉米的育种效率。

通讯：严建兵 (http://cpst.hzau.edu.cn/info/1015/1602.htm)

个人简介：1995-1999年，华中农业大学，生物技术专业学士；1998-2003年，华中农业大学，遗传学专业博士。

研究方向：作物育种。

doi: https://doi.org/10.1038/s41467-019-08786-x

Journal: Nature Communications

Published date: February 15, 2019