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.
