Project Abstract Animal cells are asymmetric, often containing different proteins at distinct areas of the membrane. For example, the cells that line our digestive tract are poised to take in nutrients from one side of the cell and deliver them to the rest of the body at the other side. This proposal examines the activity of the Par complex, a set of proteins responsible for creating and maintaining different regions of animal cell membranes. We are also examining how cellular asymmetries are translated into the complex organization seen in animal tissues and organs. One mechanism for creating structure within tissues is to create different cell types, such as neurons with the brain. In general, our work aims to understand how cells process information to specifically target polarity and fate determinants to the appropriate region of the cell at the right time, activate these complexes once they're localized, and how the activity of these complexes is translated into complex cellular functions, such as differentiation.