Fig. 7. Binary cell fate switch between RGCs and cones in Math5^-/- mice. On the left, diagrams summarize wild-type (upper) and mutant (lower) retinal phenotypes. RGCs are missing and cones are increased in the mutant. The nuclear layers are indicated by shading. The inner nuclear (INL) and plexiform layers are significantly thinner in the mutant and lamination is disrupted in places. On the right, diagrams depict three models that explain the shift from RGCs to cones, which are outlined in the text. In addition to the multipotent progenitor and hypothetical bipotential precursor cells, five differentiated retinal cell types are represented (RGCs, cones, amacrines, bipolars, and rods).