Intracellular signaling domain of dystroglycan is not required for proper retinal development. A, ILM integrity (laminin, purple), neuronal migration (DAPI, blue), and axon outgrowth (2H3, green) all appear normal in mice lacking the intracellular domain of dystroglycan (DG−/βcyt) at P0. B, Flat-mount preparations showing normal axon fasciculation (2H3) in DG−/βcyt retinas. C, D, DG−/βcyt retinas (P28) have normal cellular lamination and dendritic stratification. Scale bar, 50 μm.