Subsets of retinal cells are labeled in Isl2-GFP mice. (A) Immunofluorescent staining of GFP in a retinal flat mount preparation from an adult (P30) Isl2-GFP mouse. od, optic disc; D, dorsal; T, temporal; bar, 200 μm; (B) Higher magnification of the image in (A) reveals GFP expression in multiple cell bodies and axons (arrows), indicating labeling of RGCs. bar, 200 μm; (C-E) Cross section through an adult Isl2-GFP retina reveals GFP expression in cells of the inner nuclear layer and RGC layer; (C) Co-staining against the amacrine/RGC marker calbindin reveals a restriction of Isl2-GFP+ arbors to S3 of the inner plexiform layer (E). bar, 50 μm.