The Cohesin Complex Subunit ZmSMC Participates in Meiotic Centromere Pairing in Maize
    作者: Jing Zhang, Chao Feng, Handong Su, Yang Liu, Yalin Liu, Fangpu Han
    刊物名称: The Plant Cell
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    摘要:
    Meiosis consists of two highly conserved nuclear divisions, which allow eukaryotes to maintain their chromosome number through sexual reproduction. The successful completion of meiosis depends on homologous chromosome pairing. Centromere interactions during early meiotic prophase I facilitate homologous chromosome pairing, but the underlying mechanism is unclear. Here, we performed chromatin immunoprecipitation (ChIP)-mass spectrometry (MS) analysis of maize anthers during early meiotic prophase I using anti-CENH3 (centromeric histone H3) antibodies and determined that the cohesin subunit Structural Maintenance of Chromosome 3 (SMC3) interacts with CENH3 during this period. SMC3 is enriched at centromeres and along chromosome arms in threads from leptotene to pachytene and might promote interactions between homologous centromeres. We observed dysfunctional SMC3 assembly in meiotic-specific maize mutants with defective centromere pairing. In SMC3RNAi meiocytes, centromere pairing defects were observed during early meiotic prophase I, SMC3 was weakly associated with centromeres, and SMC3 did not localize to the chromosome arms. In wildtype mitosis, SMC3 is associated with chromatin and is enriched at centromeres from prophase to anaphase. CRISPR-CAS9-induced Zmsmc3 mutants showed premature loss of sister chromatid cohesion and mis-segregation of chromosomes in mitotic spreads. Our findings suggest that in addition to sister chromatid cohesion, ZmSMC3 participates in meiotic centromere pairing.