Fig. 9. Inhibition of TGFß signaling in vivo enhances Müller glial proliferation in response to EGF at P10. Postnatal day 10 rat pups received intraocular injections of either PBS/BSA (A-C,G), anti-TGFß cocktail (5 µg mouse-anti-TGFß and 1.25 µg TGFßRII-fc), 250 ngEGF(H), or a combination of EGF and anti-TGFß cocktail (D-F,I). Intraocular injections were followed by BrdU injections. (A-C) In PBS/BSA-injected animals, only an occasional BrdU (green) labeled cell was found. (D-F) In the anti-TGFß/EGF-treated animals, BrdU (green) and CRALBP (red) staining shows multiple double-positive cells (arrowheads) in both the inner and outer nuclear layers of the retina. (G-I) Low magnification views of control injected retina (G), EGF injected retina (H) or EGF + anti-TGFß injected retina (I). (J), Quantification of in vivo results, from counts of CRALBP⁺/BrdU⁺ cells present in central retinal sections: control, 12 (±6) cells/mm² retina; anti-TGFß, 11.1 (±4) cells/mm²; EGF, 333.5 (±92) cells/mm²; EGF + anti-TGFß, 630 (±81) cells/mm²; ^*P<0.05, ^**P<0.005, pairwise comparison (Student's t-test). Scale bar: 50 µm.