Multipotent precursors can give rise to all major cell types of the frog retina.

A prospective lineage analysis was performed to determine the variety of cell types that could be formed by individual precursor cells of the developing frog retina. Fluorescent dextran was iontophoretically injected into single cells of the embryonic optic vesicle. After further development of the embryo, labeled descendants were observed in all three layers of the larval retina. Furthermore, different clones were composed of various combinations of all major cell types, including the glial Müller cells. Hence, single optic vesicle cells have the potential to form any type of retinal cell, suggesting that the interactions that specify the differentiation pathway of retinal cells must occur late in development.