Figure 1.

Prolonged Atoh7^LacZ expression in retinas following diphtheria toxin ablation of RGCs in mice with one intact Atoh7 allele. A, C, E, LacZ histochemical staining shows that in Atoh7^LacZ/+ retinas, LacZ-positive cells are detected at the retinal margins until P8. B, D, F, Cryosections of Atoh7^LacZ/+;Pou4F2^dta/+;Six3-Cre retinas following RGC ablation show increased numbers of Atoh7^LacZ-positive cells in the retinal margin at each corresponding stage. Cells positive for LacZ are still detectable at P14 despite the presence of the same wild-type Atoh7 allele as in the controls. Scale bar, 100 μm.