An F-box protein ACOZ1 functions in crossover formation by ensuring proper chromosome compaction during maize meiosis

第一作者：Juli Jing

第一单位：中国农业大学

通讯作者：Yan He

 Abstarct 

背景回顾：Meiosis is an essential reproductive process to create new genetic variation. During early meiosis, higher order chromosome organization creates a platform for meiotic processes to ensure the accuracy of recombination and chromosome segregation. 

减数分裂是生物在生殖过程中创造新的遗传变异所必需的。在减数分裂早期，高阶染色体组织为减数分裂过程创造了一个平台，以确保精确的重组和染色体分离。

提出问题：However, little is known about regulatory mechanisms underlying dynamic chromosome organization in plant meiosis. 

然而，目前对于植物减数分裂过程中有关动态染色体组织的调控机制知之甚少。

主要发现：Here, we describe abnormal chromosome organization in zygotene1 (ACOZ1), which encodes a canonical F-box protein in maize. 

本文中，作者报道了玉米中一个编码F-box蛋白的ACOZ1基因参与了玉米的染色体组织。

结果1-acoz1突变体：In acoz1 mutant meiocytes, chromosomes maintain a leptotene-like state and never compact to a zygotene-like configuration. Telomere bouquet formation and homologous pairing are also distorted and installation of synaptonemal complex ZYP1 protein is slightly defective. Loading of early recombination proteins RAD51 and DMC1 is unaffected, indicating that ACOZ1 is not required for DSB formation or repair. However, crossover formation is severely disturbed. 

在acoz1突变的减数分裂细胞中，染色体保持一种类细线期的状态，并且从不会压缩成偶线期那样的构象。端粒束的形成和同源配对出现缺陷，联会复合体ZYP1蛋白的安装有轻微缺陷。早期重组蛋白RAD51和DMC1的装载不受影响，表明ACOZ1不是DSB形成或修复所必需的。然而，交换（crossover）受到了严重的干扰。

结果2-ACOZ1蛋白定位：The ACOZ1 protein localizes on the boundary of chromatin, rather directly to chromosomes. 

ACOZ1蛋白定位于染色质的边界，而不是直接定位于染色体。

结果3-ACOZ1互作蛋白：Furthermore, we identified that ACOZ1 interacts with SKP1 through its C-terminus, revealing that it acts as a subunit of the SCF E3 ubiquitin/SUMO ligase complex. 

此外，作者发现ACOZ1通过其C-末端与SKP1互作，表明其是SCF E3泛素/SUMO连接酶复合物的一个亚基。

结论：Overall, our results suggested that ACOZ1 functions independently from core meiotic recombination pathway to influence crossover formation by controlling chromosome compaction during maize meiosis.

综上，本文的研究结果表明，ACOZ1独立于核心的减数分裂重组途径发挥作用，在玉米减数分裂期间通过控制染色体压缩来影响交叉（crossover）的形成。

** 贺 岩 **

doi: https://doi.org/10.1111/nph.18116

Journal: New Phytologist​

Published date: March 24, 2022