Fig. 4. TGFß ligands and receptors are expressed in P4 rat retina. (A-F) Immunolocalization of TGFßRI (red, A) and II (red, B) in nestin-positive (green, C,F) processes of progenitor cells in the central retina. Arrowheads indicate double-labeled cells. (G) Quantitative RT-PCR results show TGFß2 is expressed 80-fold higher than TGFß3 and eightfold higher than TGFß1 in P4 retinal tissue. (H-J) TGFß2 (red) is expressed by ß3 tubulin-positive (green) ganglion and amacrine cells (arrowheads). (K) RT-PCR for TGFßs and receptors P4 retinal mRNA. Scale bar: 50 µm.