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Updated: Sep 20, 2025

Preparation of Meiotic Chromosome Spreads from Mouse Oocytes for Assessment of Synapsis and Recombination
Published on: July 18, 2025
ZmSPO11-2 is critical for meiotic recombination in maize
Menghan Li1,2, Shuyue Li1, Yan He2
1MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China.
Abstract:
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.
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