Receptor Phosphatase Roles in Self-Avoidance and Arbor Tiling

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Eduardo Macagno IOS 0745134: Receptor Phosphatase Roles in Self-Avoidance and Arbor Tiling As an embryo develops, groups of 'like' cells, particularly some types of nerve cells, become organized in functionally important ways, dividing and sharing space in developing tissues and organs. A good example of this process is the growth of the sensory "arbors" of cells that detect mechanical stimuli, which expand until they run into each other and stop growing, thus achieving complete and non-redundant coverage of the skin, much as tiles cover a floor. This "tiling" process is critical for an animal to be able to detect where stimuli are coming from on their surfaces and thus to respond appropriately - leaving uncovered areas would lead to dangerous "blind spots." Tiling requires not only that branches of cells of the same type recognize and avoid each other (mutual exclusion) but that branches of the same cell do so as well (self-avoidance). This project is designed to yield information on the mechanisms responsible for mutual exclusion and self-avoidance, an important step towards a general understanding the assembling of complex cellular ensembles. The proposed studies will be carried out on a specific set of cells of the medicinal leech, a uniquely advantageous model system that allows the detailed characterization of cellular interactions as they occur in the living, intact embryo. Previous work from this laboratory identified a membrane receptor on the surfaces of these cells that, the researchers have proposed, creates a signal to stop growing and retract when it meets with other copies of itself on other parts of a cell. The proposed work will focus on understanding exactly how this class of receptor regulates cellular growth and arbor extension. The Broader Impacts of this proposal are twofold. First, the work will provide valuable insights into the mechanistic underpinnings of arbor tiling and the genesis of multicellular structures. And second, this work will provide a multitude of training opportunities for undergraduate students, including those from underrepresented minorities.