Analysis of Intercellular Signaling Governing Plant Cell Polarization

发育生物学的一个基本挑战是了解单细胞受精卵是如何产生多细胞生物体特有的各种细胞类型的。在植物中，就像在其他真核生物中一样，新的细胞类型通常是通过不对称分裂形成的，其中一个细胞不平等地分裂，产生具有不同发育命运的子细胞。不对称分裂取决于细胞在分裂前极化(变得不对称)的能力。一种玉米蛋白(PAN1)已被发现，它似乎是一种受体，通过接收信号，一个细胞告诉它的邻居极化和不对称分裂，以创造一种新的细胞类型。本项目旨在通过多种途径阐明PAN1的功能。PAN1在细胞内的定位将与PAN1被假定信号激活的位置一起确定。将对PAN1进行研究，以确定其功能是否涉及与一类先前与细胞极化有关的蛋白质的相互作用。将采取互补的方法来确定激活PAN1的假定信号分子。最后，我们将使用遗传学方法来研究模式物种拟南芥中类PAN1蛋白的功能。这项工作将提高我们对细胞相互通信以协调细胞极化和不对称分裂等发育中重要事件的机制的理解。参与这项工作将为博士生、博士后研究员和一系列本科生提供有价值的跨学科培训。此外，该项目的所有参与者将为墨西哥下加利福尼亚自治大学作物生物技术研讨会的教学做出贡献，该研讨会将增加墨西哥年轻科学家的教育机会，并促进美国和墨西哥科学家之间的联系。

A fundamental challenge in developmental biology is to understand how a single celled zygote can give rise to the wide variety of cell types characteristic of a multicellular organism. In plants, as in other eukaryotes, new cell types are often formed via asymmetric divisions, where one cell divides unequally to produce daughter cells with different developmental fates. Asymmetric divisions depend on the ability of a cell to polarize (become asymmetric) before dividing. A maize protein (PAN1) has been identified that appears to function as a receptor, receiving a signal by which one cell tells its neighbor to polarize and divide asymmetrically to create a new cell type. This project is aimed at elucidating the function of PAN1 through a variety of approaches. The intracellular localization of PAN1 will be determined along with the site at which PAN1 becomes activated by the putative signal. PAN1 will be investigated to determine whether its function involves an interaction with a class of proteins previously implicated in cell polarization. Complementary approaches will be taken to identify the putative signaling molecule that activates PAN1. Finally, a genetic approach will be used to investigate the functions of PAN1-like proteins in the model species Arabidopsis thaliana. This work will improve our understanding of the mechanisms by which cells communicate with each other to coordinate important events in development such as cell polarization and asymmetric division. Participation in this work will provide valuable, interdisciplinary training for a Ph.D. student, a postdoctoral fellow, and a series of undergraduates. In addition, all participants in the project will contribute to the teaching of a Workshop in Crop Biotechnology at the Univeridad Autonoma de Baja California in Mexico, which will enhance educational opportunities for young scientists in Mexico as well as fostering connections between U.S. and Mexican scientists.