Fig. 3: Deficiency of Mkk4 or Mkk7 does not prevent JNK–JUN signaling after axonal injury in RGC somas or axons.

a Representative sections containing the optic nerve head demonstrate robust expression of pJNK 2 h after CONC in WT controls and in Mkk4 and Mkk7 mutants (N ≥ 3 per genotype). b Representative retinal flat mounts from each group reveal robust levels of pJUN in TUJ-1-positive RGCs 1 day after CONC (N ≥ 3 per genotype). Scale bars: 50 μm. c Representative western blots showing levels of pJUN protein in WT and Six3cre driven conditional knockouts after CONC. d pJUN protein levels were significantly reduced by 61.8% in Mkk4- and by 83.1% in Mkk7-deficient mutants compared to littermate WT controls (N ≥ 3 per genotype, *P < 0.001)