From progenitors to differentiated cells in the vertebrate retina

Multipotent retinal progenitors undergo a varied number of divisions to produce clones of heterogeneous sizes and cell types. We describe the transition from a proliferating progenitor to a differentiated postmitotic cell and discuss how controls of proliferation operate within individual cells as well as in the whole tissue. We discuss how extracellular and intracellular signaling, transcriptional regulation, cell cycle kinetics, interkinetic nuclear migration, orientation of cell division, and epigenetic modifications all interact to regulate a progenitor's transition from division to differentiation. We also propose some directions for future research.