Molecular Genetics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Curr Biol. 2010 Mar 9;20(5):452-7. doi: 10.1016/j.cub.2010.01.018. Epub 2010 Feb 18.
Cell divisions generating daughter cells different in size, shape, identity, and function are indispensable for many developmental processes including fate specification, tissue patterning, and self-renewal. In animals and yeast, perturbations in factors required for well-described asymmetric cell divisions generally yield cells of equal fate. Here we report on SCHIZORIZA (SCZ), a single nuclear factor with homology to heat-shock transcription factors that controls the separation of cell fate in a set of stem cells generating different root tissues: root cap, epidermis, cortex, and endodermis. Loss-of-function, expression, and reconstitution experiments indicate that SCZ acts mainly from within its cortical expression domain in the stem cell niche, exerting both autonomous and nonautonomous effects to specify cortex identity and control the separation of cell fates in surrounding layers. Thus, SCZ defines a novel pathway for asymmetric cell division in plants.
产生在大小、形状、身份和功能上不同的子细胞的细胞分裂对于许多发育过程是必不可少的，包括命运特化、组织模式形成和自我更新。在动物和酵母中，干扰已知不对称细胞分裂所需的因素通常会产生具有相同命运的细胞。在这里，我们报告了 SCHIZORIZA（SCZ），一种与热休克转录因子具有同源性的单一核因子，它控制着一组干细胞产生不同根组织的细胞命运的分离：根冠、表皮、皮层和内皮层。功能丧失、表达和重建实验表明，SCZ 主要从其在干细胞生态位中的皮层表达域内发挥作用，发挥自主和非自主作用来指定皮层身份并控制周围层细胞命运的分离。因此，SCZ 定义了植物中不对称细胞分裂的新途径。
