Fig. 2. Identification of Ptf1a cell lineage in Ptf1a^+/Cre(ex1) R26R retinae of adult mice. Ptf1a-mediated ß-galactosidase expression is co-localized with markers of specific classes of retinal neurons in the adult Ptf1a^+/Cre(ex1) R26R retina. (A,D,G,J,M,P) Expression of selected markers is shown with Alexa 488 (green). (B,E,H,K,N,Q) Expression of ß-galactosidase is shown by immunostaining with Alexa 568 (red). (C,F,I,L,O,R) In merged images, the yellow color represents co-localization of ß-galactosidase with a specific marker. (C) ß-galactosidase is present in the GCL (arrows) but does not co-localize with Thy1.2. (F) ß-galactosidase coexpression with syntaxin, a general marker of amacrine cells, is evident in INL (arrows). (I) GABA coexpression with ß-galactosidase is demonstrated in GABAergic amacrine (arrowheads, yellow) and displaced amacrine cells (arrows, yellow). (L) Coexpression of ß-galactosidase with glycine transporter 1 (GlyT1) is found in glycinergic amacrine cells (arrows). (O) ß-galactosidase coexpression with calbindin is present in horizontal cells (arrows, yellow). PKC--expressing bipolar interneurons (P, arrowheads) do not co-localize with ß-galactosidase expression (R, inset). Insets in merge images (C,F,I,L,O,R) represent a 2.67-fold enlargement. DAPI staining in E shows the retinal nuclear layers. Scale bars: 50 µm. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OPL, outer plexiform layer.