A model for the role of MATH5 in the sequential formation of early-born retinal neurons. During normal retinogenesis, the expression of MATH5 starts in selected retinal progenitors and promotes the cell cycle exit. The transient expression of MATH5 makes the postmitotic precursors become RGC-competent and temporarily blocks non-RGC differentiation programs by suppressing the expression of retinogenic factors such as NEUROD1, NGN2, MATH3, BHLHB5, and RXRγ. During this competence period, MATH5 activates a network of transcription factors including BRN3B and ISL1 in some precursors to initiate the RGC differentiation program. The remaining precursors lose RGC-competence when MATH5 expression ceases, express other retinogenic factors and generate horizontal cells (all horizontal cells are of Math5-lineage), or along with the non-Math5-lineage precursors, produce amacrine, rod, and cone cells.