Table 1.

Participation of Proneural bHLH Genes in Various Steps of Retinal Development

ash1	Multipotent progenitor cells at late stages, generation of bipolar cells and rod photoreceptors, neuron vs glia (18,23,69)
ash3	Progenitor cells (20,21)
ath3	Generation of bipolar cells and amacrine cells (23,44), neuron vs glia (23)
ath5	Progenitor cells leading to multiple cell types, including photoreceptor cells and ganglion cells (31,60), ganglion cell generation (25,27-29,32), and ganglion cell differentiation (26,30,31,32)
neuroD	Photoreceptor fate specification (33,35,44), photoreceptor survival (36), amacrine cell fate specification (34,44), neural vs glia (34)
ngn2	Multipotent progenitor cells leading to multiple cell types (refs. 38 and 39; Ma et al., submitted)
NSCL1	Cell proliferation and cell death (40), ganglion cell production when coexpressed with ath5 (32), ganglion cell differentiation (31,32)
NSCL2	Horizontal and amacrine neuron differentiation (ref. 41; our unpublished data 2004–2005)