Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland.
Centro de Biología Molecular Severo Ochoa CSIC-UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain.
Dev Cell. 2021 Jul 12;56(13):1945-1960.e7. doi: 10.1016/j.devcel.2021.06.004. Epub 2021 Jun 29.
Establishing the embryonic body plan of multicellular organisms relies on precisely orchestrated cell divisions coupled with pattern formation, which, in animals, are regulated by Polycomb group (PcG) proteins. The conserved Polycomb Repressive Complex 2 (PRC2) mediates H3K27 trimethylation and comes in different flavors in Arabidopsis. The PRC2 catalytic subunit MEDEA is required for seed development; however, a role for PRC2 in embryonic patterning has been dismissed. Here, we demonstrate that embryos derived from medea eggs abort because MEDEA is required for patterning and cell lineage determination in the early embryo. Similar to PcG proteins in mammals, MEDEA regulates embryonic patterning and growth by controlling cell-cycle progression through repression of CYCD1;1, which encodes a core cell-cycle component. Thus, Arabidopsis embryogenesis is epigenetically regulated by PcG proteins, revealing that the PRC2-dependent modulation of cell-cycle progression was independently recruited to control embryonic cell proliferation and patterning in animals and plants.
建立多细胞生物的胚胎体计划依赖于精确协调的细胞分裂与模式形成，在动物中，这些过程受到 Polycomb 组（PcG）蛋白的调控。保守的 Polycomb 抑制复合物 2（PRC2）介导 H3K27 三甲基化，在拟南芥中有不同的形式。PRC2 的催化亚基 MEDEA 对于种子发育是必需的；然而，PRC2 在胚胎模式形成中的作用已被否定。在这里，我们证明了来自 medea 卵子的胚胎会流产，因为 MEDEA 对于早期胚胎的模式形成和细胞谱系决定是必需的。与哺乳动物中的 PcG 蛋白相似，MEDEA 通过抑制编码核心细胞周期成分的 CYCD1;1 来控制细胞周期进程，从而调节胚胎的模式形成和生长。因此，拟南芥胚胎发生受到 PcG 蛋白的表观遗传调控，揭示了 PRC2 依赖性细胞周期进程的调节在动物和植物中被独立招募来控制胚胎细胞增殖和模式形成。
