Development in all multi-cellular organisms depends on an asymmetric distribution of patterning molecules that occurs during the earliest cleavage cycles. As a consequence of the early establishment of asymmetry, cells embark on different pathways to ultimately become the recognizable organs of the adult. This proposal focuses on the role of two signaling pathways - signaling through the NMDA receptor and signaling through the NOTCH pathway - in the establishment of asymmetry and cell fate in the mud snail Ilyanassa. Preliminary findings suggest that blocking either of these pathways disrupts important events in determining the fate of particular cells and results in a failure to establish bilateral symmetry in the embryo. The Nagy lab uses Ilyanassa as their model system as their embryos undergo a series of pronounced asymmetric cell divisions and have a distinctive pattern of cell fates, characteristics that make them ideally suited for the proposed research. Significantly, the NMDA receptor is best known for its role in synaptic transmission and memory and learning and has not previously been implicated in early cell division in any animal species. The expected results will broadly impact the scientific community because asymmetric cell cleavage is a fundamental property of stem cells and increasing our understanding of stem cell behavior effects the ability of the scientific community to improve health care through treatments utilizing stem cells. The proposed work forms the basis of graduate and undergraduate training and outreach to local elementary and high schools. As these experiments are straightforward methodologically, they provide an excellent opportunity to introduce student and teachers-in training to the beauty of the invertebrate embryo and to modern methods in cell and molecular biology, imaging, and design and interpretation of scientific experiments. The lab actively participates in programs designed to recruit under-represented minorities from the local high schools and community college for research experiences.