Figure 5. Coimmunostaining of P4 foveal glial cells with the Müller cell marker CRALBP and GFAP. Coimmunostaining of foveal cryosections from P4 with cellular retinaldehyde-binding protein (CRALBP), which is a specific marker of Müller cells in humans, and glial fibrillar acidic protein (GFAP) shows that the GFAP-positive cells at the roof of the foveal pit (A, B, and inset) do not express CRALBP (C, D, and inset). E: Costaining with GFAP and CRALBP shows that the GFAP-positive cells at the roof of the pit (arrow) do not express CRALBP and are distinct from the CRALBP-positive Müller glial cells.