Fig. 1

Retinal Brn3a ablation results in specific RGC defects. a-b Summary of Brn3a RGC phenotype, based on previous work [2, 9, 28]. Distribution of dendritic arbors for Brn3a heterozygote (a, Brn3a^AP/WT) and Brn3a knock-out (b, Brn3a^AP/KO) RGCs. a Dendrites of Brn3a^AP/WT RGCs, including ON-OFF-DS bistratified (left) and midget-like (right) cells, occupy the outer two-thirds of the Inner Plexiform Layer (IPL, gray). b Midget-like cells are absent from Brn3a^AP/KO RGCs, and the dendrites of remaining cells are co-stratifying with the inner and outer Starburst Amacrine cell dendritic arbors (blue lines). c-d Indirect immunofluorescence illustrating Brn3a^AP RGC arbors and cell bodies (red), and Brn3a transcription factor expression (green) in Rax:Cre; Brn3a^CKOAP/WT (c) and Rax:Cre; Brn3a^CKOAP/KO (d) adult retinas. Note the gap of Brn3a^AP staining in d, and the absence of Brn3a TF positive cell bodies in the GCL. ONL = Outer Nuclear Layer; OPL = Outer Plexiform Layer; INL = Inner Nuclear Layer; IPL = Inner Plexiform Layer; GCL = Ganglion Cell Layer. Red bars in IPL of (d) indicate the position of inner and outer ChAT bands. Arrowheads are showing AP-expressing cells. Scale bar in D, 25 μm