Fig. 1. Spatial and temporal expression patterns of Ptf1a protein during mouse retinogenesis. (A-G) Retinal sections from the indicated developmental stages were immunostained with an anti-Ptf1a antibody (red) and nuclei were counterstained with YoPro-1 (green). The expression of Ptf1a commences at E12.5 in the central retina (B), peaks around E14.5 in the outer neuroblastic layer (C) and continues to be strong around E18.5 (E). It begins to be downregulated significantly at P2 (F) and eventually disappears around P6-P7. At P6, Ptf1a expression is completely downregulated from the central retina. (H) Retinal sections from E18.5 Ptf1a^Cre/Cre embryos immunostained with an anti-Ptf1a antibody. (I) Retinal sections from BrdU-labeled E14.5 embryos were double immunostained with anti-Ptf1a (red) and anti-BrdU (green) antibodies. There was no colocalization between Ptf1a-immunoreactive nuclei and the S-phase nuclei immunoreactive for BrdU. Scale bar: 50 µm. Abbreviations: R, retina; L, lens; onbl, outer neuroblastic layer; inbl, inner neuroblastic layer; INL, inner nuclear layer; GCL, ganglion cell layer; IPL, inner plexiform layer.