Fig. 9. Expression of TGF-ß isoforms (B,C) and receptor (TßRII; A) in anti-NGF-treated E6 chick retinae, revealed by indirect immunofluorescence stains. As in control retinae, TßRII immunoreactivity is distributed evenly over the entire retinal surface (A), whereas TGF-ß2 (B) and TGF-ß3 (C) immunoreactivity was observed mainly in the central retina in the region around the optic nerve head. In addition, TGF-ß3 is localized in structures that span the neuroepithelium, resembling Müller glia cells or radial Müller fibers (arrowheads in C), and in the presumptive ganglion cell layer (arrow in C). nr, neural retina; on, optic nerve; ov, optic ventricle; pe, pigment epithelium. Scale bar: 50 µm.