Fig. 6. Cell autonomous and non-autonomous components of Pcdh--dependent cell survival. (A) Schematic of the recombination pattern in Pax6-Cre retina. In Pax6-Cre;Pcdh- ^fcon3/fcon3 mutants, all cells are Pcdh- negative in peripheral retina, but only Pax6-positive (+) amacrine cells are Pcdh- negative in the central sector. (B-E) Immunolabeling of central and peripheral regions of Pax6-Cre;Pcdh- ^+/fcon3 and Pax6-Cre;Pcdh- ^fcon3/fcon3 mutant retinas with GFP and Brn3a antibodies. Anti-GFP labels both Pax6-Cre-ires-GFP positive amacrine cells (asterisks) and Pcdh--GFP proteins (arrows). In unrecombined portions of the central Pax6-Cre;Pcdh- ^fcon3/+ and Pax6-Cre;Pcdh- ^fcon3/fcon3 retinas, Pcdh--GFP proteins are visible in the outer segments, OPL, and retinal axons (arrows). In peripheral regions, Pcdh--GFPs are absent. In both regions, mutant retinas have reduced numbers of Pax6-positive amacrine cells; Brn3a-positive RGCs are dramatically decreased in the mutant peripheral sector while slightly decreased in the central sector. (F) Quantification of retinal cell types in central regions of Pax6-Cre;Pcdh- ^fcon3/fcon3 retinas, expressed as a percentage of cells in Pax6-Cre;Pcdh- ^fcon3/+ littermates. Six to eight animals per genotype were analyzed; ^**P<0.05; ^**P<0.01; ^***P<0.0001, by Student's t-test or Mann-Whitney test. Scale bar: 50 µm.