SUMMARY
Cell migration and axon guidance are important steps in the formation of neural circuits. Both steps depend on the interactions between cell surface receptors and molecules on cells along the pathway. In addition to cell-cell adhesion, these molecular interactions provide guidance information. The fine-tuning of cell-cell adhesion is as an important aspect of cell migration, axon guidance, and synapse formation. Here, we show that Endoglycan, a sialomucin, plays a role in axon guidance and cell migration in the central nervous system. In the absence of Endoglycan, commissural axons failed to cross the midline of the spinal cord. In the developing cerebellum, a lack of Endoglycan prevented migration of Purkinje cells and resulted in a stunted growth of the cerebellar lobes. Taken together, these results support the hypothesis that Endoglycan acts as a negative regulator of cell-cell adhesion in both commissural axon guidance and Purkinje cell migration.
