Function of the Arabidopsis Gene TORMOZ in Cell Division and Development

细胞分裂的控制是多细胞生物发育的一个重要特征。在高等植物中，细胞分裂的时间和面都受到发育信号的调控和响应。尽管有广泛的研究表明细胞骨架在执行在预定平面上分裂的决定中很重要，但关于其潜在的分子机制的信息很少。在拟南芥中发现了一种叫做tormoz （toz）的突变，在这种突变中，胚胎的纵向分裂是随机的。突变体胚胎停滞不前，但可以恢复产生具有严重形态缺陷的幼苗。预测的TOZ基因产物似乎在从酵母到人类的每一个测序真核生物中都有密切的同源性。然而，toz相关蛋白的功能尚未在任何物种中进行过研究。TOZ基因产物在拟南芥细胞分裂和发育中的作用将被进一步研究。首先，toz突变苗将用于检查植物发育如何受到突变的影响，包括细胞分裂面缺陷对模式和细胞规格的干扰程度。其次，将对toz突变细胞进行研究，以确定toz在植物有丝分裂和细胞分裂的细胞骨架组织中的可能功能。第三，研究拟南芥细胞分裂过程中TOZ基因产物的胞内定位，为其参与分裂平面控制的机制提供线索。第四，我们将尝试确定TOZ可能的相互作用伙伴，以获得关于TOZ蛋白执行其功能的分子机制的进一步信息。这些研究将有助于了解植物发育过程中细胞分裂的控制，并可能增加对动物和真菌细胞分裂的认识。该项目包括培养学生和博士后以及少数民族的参与。

0235548SundaresanThe control of cell division is an important feature of development in multicellular organisms. In higher plants, both the timing and the plane of cell division are regulated and responsive to developmental cues. Although there are extensive studies showing that the cytoskeleton is important in executing the decision to divide in a predetermined plane, there is little information on the underlying molecular mechanisms. A mutation in Arabidopsis called tormoz (toz) has been identified, in which longitudinal divisions of the embryo are randomized. The mutant embryos arrest but can be rescued to generate seedlings which have severe morphological defects. The predicted TOZ gene product appears to have a close homolog in every sequenced eukaryote from yeast to humans. However, the function of the TOZ-related proteins has not been previously studied in any species. The role of the TOZ gene product in cell division and development in Arabidopsis will be investigated. First, the toz mutant seedlings will be used to examine how plant development has been affected by the mutation, including the extent to which patterning, and cell specification have been perturbed by the defect in cell division planes. Second, studies of toz mutant cells will be undertaken to determine possible functions of TOZ in the organization of the plant cytoskeleton for mitosis and cytokinesis. Third, the intracellular localization of the TOZ gene product during cell division in Arabidopsis will be studied to generate clues to the mechanism by which it may be involved in the control of division plane. Fourth, we will attempt to identify putative interacting partners of TOZ in order to gain further information on the molecular mechanism by which the TOZ protein executes its function. These studies will help to understand the control of cell division in plant development, and may add to the knowledge of cell division in animals and fungi. The project includes training of students and postdoctoral fellows and minority participation.