Fig. 16

Distinct Brn3a effects on the expression of two adhesion molecules – Elfn1 and Cdh4. Retinal sections were prepared from either Rax:Cre; Brn3a^CKOAP/WT (a, c, e, g) or Rax:Cre; Brn3a^CKOAP/KO (b, d, f, h) mice at P7 (a, b, e, f) or P22 (c, d, g, h). Immunostaining for either Elfn1 (green, a-d) or Cdh4 (green, e-h) was performed in conjunction with immunostaining for Brn3a^AP RGCs (red, AP) and nuclear layers counterstain (DAPI, in blue, in merge channel). For every immunostaining Elfn1 (left), AP (middle) and merge (right) channels are shown. White arrowheads, asterisks and arrows indicate Horizontal Cells, Amacrine Cells and RGCs. Green arrowheads in C and D reveal synaptic staining in the OPL, as previously reported [81]. Green stippled lines in the merge channel indicate lamination of Elfn1⁺ or Cdh4⁺ neurites in the IPL, if present. Scale bar in H = 50 μm. i-l Schematics of Brn3a^AP RGCs dendrites (red) and Elfn1 (orange, I, J) and Cdh4 (green or orange, K, L) lamination in the IPL, at P7 (I, K) or P22 (J, L), in Rax:Cre; Brn3a^CKOAP/WT (left, WT) or Rax:Cre; Brn3a^CKOAP/KO (right, KO) retinas. Elfn1 stains only a few diffuse dendrites at P7, however a sharp lamina is labelled in P22, and this lamina is absent from Brn3a null retinas. Cdh4⁺ dendrites form one clear lamina at P7 and two distinct laminae at P22, however the lamination pattern is not affected by Brn3a ablation