Fig. 5

Genetic reduction of microglia impairs retinal reactive proliferation in response to injury. (A) In contrast to heterozygous control siblings (irf8+/?), interferon regulatory factor 8 (irf8) homozygous myeloid-deficient mutant retinae (irf8?/?) display a decreased number of L-Plastin+ leukocytes in homeostasis. (B) Quantifications of L-Plastin+ cells in irf8?/? and control heterozygous siblings irf8+/?. (C) Scheme of experimental outline. irf8?/? and irf8+/? animals received an EdU pulse at 3 days post lesion (dpl) and were analyzed at 4 dpl. (D) During regeneration, the accumulation of L-Plastin+ cells at the outer nuclear layer (ONL) is impaired in irf8?/? but not in control irf8+/? siblings. Moreover, the number of EdU+ cells appears decreased in irf8?/? retinae. (E) Quantification of L-Plastin+ cells and EdU+ nuclei in irf8?/? and control irf8+/? animals at 4 dpl, showing reduced amounts of positive cells, respectively. Scale bar: 50 µm. Error bars indicate SEM; *** = p < 0.001; N = 5; two-tailed t-Test; INL = inner nuclear layer; GCL ganglion cell layer.