Li Menghan, Li Shuyue, He Yan, Wang Yan, Zhang Ting, Li Ping, He Yan
MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China.
College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi, 860000, China.
Chromosome Res. 2022 Dec;30(4):415-428. doi: 10.1007/s10577-022-09694-5. Epub 2022 Jun 8.
Most plant species have three or more SPO11/TOPOVIA homologs and two TOPOVIB homologs, which associate to trigger meiotic double-strand break (DSB) formation and subsequent meiotic recombination. In Zea mays L. (maize), ZmSPO11-1 and ZmMTOPVIB have been reported to be indispensable for the initiation of meiotic recombination, yet the function of ZmSPO11-2 remains unclear. In this study, we characterized meiotic functions of ZmSPO11-2 during male meiosis in maize. Two independent Zmspo11-1 knock-out mutants exhibited normal vegetative growth but both male and female sterility. The formation of meiotic DSBs of DNA molecules was fully abolished in the Zmspo11-2 plants, leading to the defective homologous chromosome paring, synapsis, recombination, and segregation. However, the bipolar spindle assembly was not noticeably affected in Zmspo11-2 meiocytes. Overall, our results demonstrate that as its partner ZmSPO11-1 and ZmMTOPVIB, ZmSPO11-2 plays essential roles in DSB formation and homologous recombination in maize meiosis.
大多数植物物种有三个或更多的SPO11/TOPOVIA同源物和两个TOPOVIB同源物，它们相互作用以触发减数分裂双链断裂（DSB）的形成及随后的减数分裂重组。在玉米（Zea mays L.）中，ZmSPO11-1和ZmMTOPVIB已被报道对于减数分裂重组的起始是不可或缺的，然而ZmSPO11-2的功能仍不清楚。在本研究中，我们对ZmSPO11-2在玉米雄配子减数分裂过程中的功能进行了表征。两个独立的Zmspo11-1基因敲除突变体表现出正常的营养生长，但雄花和雌花均不育。Zmspo11-2植株中DNA分子减数分裂DSB的形成完全被消除，导致同源染色体配对、联会、重组和分离出现缺陷。然而，Zmspo11-2减数分裂细胞中的双极纺锤体组装未受到明显影响。总体而言，我们的结果表明，与它的伙伴ZmSPO11-1和ZmMTOPVIB一样，ZmSPO11-2在玉米减数分裂的DSB形成和同源重组中发挥着重要作用。
