Borg Michael, Rutley Nicholas, Kagale Sateesh, Hamamura Yuki, Gherghinoiu Mihai, Kumar Sanjeev, Sari Ugur, Esparza-Franco Manuel A, Sakamoto Wataru, Rozwadowski Kevin, Higashiyama Tetsuya, Twell David
Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom.
Agriculture and Agri-Food Canada, Saskatoon SK S7N OX2, Canada.
Plant Cell. 2014 May;26(5):2098-2113. doi: 10.1105/tpc.114.124743. Epub 2014 May 29.
The production of the sperm cells in angiosperms requires coordination of cell division and cell differentiation. In Arabidopsis thaliana, the germline-specific MYB protein DUO1 integrates these processes, but the regulatory hierarchy in which DUO1 functions is unknown. Here, we identify an essential role for two germline-specific DUO1 target genes, DAZ1 and DAZ2, which encode EAR motif-containing CH-type zinc finger proteins. We show that DAZ1/DAZ2 are required for germ cell division and for the proper accumulation of mitotic cyclins. Importantly, DAZ1/DAZ2 are sufficient to promote G2- to M-phase transition and germ cell division in the absence of DUO1. DAZ1/DAZ2 are also required for DUO1-dependent cell differentiation and are essential for gamete fusion at fertilization. We demonstrate that the two EAR motifs in DAZ1/DAZ2 mediate their function in the male germline and are required for transcriptional repression and for physical interaction with the corepressor TOPLESS. Our findings uncover an essential module in a regulatory hierarchy that drives mitotic transition in male germ cells and implicates gene repression pathways in sperm cell formation and fertility.
被子植物中精子细胞的产生需要细胞分裂和细胞分化的协调。在拟南芥中，生殖系特异性MYB蛋白DUO1整合了这些过程，但DUO1发挥作用的调控层级尚不清楚。在这里，我们确定了两个生殖系特异性DUO1靶基因DAZ1和DAZ2的重要作用，它们编码含EAR基序的CH型锌指蛋白。我们表明，DAZ1/DAZ2是生殖细胞分裂和有丝分裂细胞周期蛋白正常积累所必需的。重要的是，在没有DUO1的情况下，DAZ1/DAZ2足以促进G2期到M期的转变和生殖细胞分裂。DAZ1/DAZ2也是DUO1依赖性细胞分化所必需的，并且是受精时配子融合所必需的。我们证明，DAZ1/DAZ2中的两个EAR基序介导它们在雄性生殖系中的功能，并且是转录抑制以及与共抑制因子TOPLESS进行物理相互作用所必需的。我们的研究结果揭示了一个调控层级中的重要模块，该模块驱动雄性生殖细胞的有丝分裂转变，并暗示基因抑制途径在精子细胞形成和育性中的作用。
