华中农大，中科院合作发表文章揭示调控新机理

　　

　油菜是全球最重要的油料作物之一，杂种优势利用是提高油菜产量的重要途径。目前对于油菜雄性不育调控分子机理的研究还非常初步。Yi3A是我国上世纪70年代发现的细胞核雄性不育系，曾选配出多个油菜杂交种，并在生产上推广。该雄性不育系统的恢保关系受MS5位点的三个复等位基因控制，其中MS5b为雄性不育基因，MS5a为育性恢复基因，MS5c为育性保持基因，但是对其育性调控的分子机理尚缺乏足够的细胞学与遗传学证据。

　　华中农业大学杨光圣课题组与中国科学院遗传与发育生物学研究所程祝宽课题组合作，发现MS5基因通过调控性母细胞减数分裂进程，影响配子发育，最终控制植株的育性。该基因编码一个功能未知的特异蛋白，在芸薹属之外其他物种中找不到明显的同源蛋白。而MS5三个复等位基因所导致的育性差异是通过调节功能蛋白表达水平来实现的。相关研究初步解释了油菜MS5基因调控育性的分子机制，一方面为解析减数分裂调控的分子机理提供直接证据，亦为该雄性不育系统的广泛应用奠定理论基础。

　　相关论文于5月18日在Plant Cell 杂志上在线发表（DOI:10.1105/tpc.15.01018）。华中农业大学博士研究生辛强和中科院遗传发育所助理研究员沈懿为该文章的共同第一作者，研究员程祝宽和副教授洪登峰为该文章共同通讯作者。该研究得到国家自然科学基金委、科技部等项目的资助。

 

图1 油菜不同基因型材料的育性鉴定 

 

图2 MS5^bMS5^b性母细胞中减数分裂进程停滞 

原文摘要：

MS5 mediates early meiotic progression and its natural variants may have applications for hybrid production in Brassica napus

During meiotic prophase I, chromatin undergoes dynamic changes to establish a structural basis for essential meiotic events. However, the mechanism that coordinates chromosome structure and meiotic progression remains poorly understood in plants. Here, we characterized a spontaneous sterile mutant MS5bMS5b in oilseed rape (Brassica napus L) and found its meiotic chromosomes were arrested at leptotene. MS5 is preferentially expressed in reproductive organs and encodes a Brassica-specific protein carrying conserved coiled-coil and DUF626 domains with unknown function. MS5 is essential for pairing of homologs in meiosis, but not necessary for the initiation of DNA double-strand breaks. The distribution of the axis element-associated protein ASY1 occurs independently of MS5, but localization of the meiotic cohesion subunit SYN1 requires functional MS5. Furthermore, both the central element of the synaptonemal complex and the recombination element do not properly form in MS5bMS5b mutants. Our results demonstrate that MS5 participates in progression of meiosis during early prophase I and its allelic variants lead to differences in fertility, which may provide a promising strategy for pollination control for heterosis breeding.