Fig. 3

Early postnatal EdU incorporation is reduced in Mertk cKO animals, independent of changes in microglial density or proliferation. A EdU-labelling paradigm. Mertk WT or Mertk cKO mice aged P5 and P25 were injected with EdU (50 mg/kg) over three consecutive days prior to collection for immunohistochemistry (IHC) analysis at the midline of the corpus callosum at P8 and P28, respectively (n = 9–12 mice per group). B Representative immunofluorescence images of P8 Mertk WT and cKO corpus callosum tissue stained for Iba1 (yellow) and EdU (magenta), in addition to Hoechst nuclear stain (cyan). Arrowheads indicate EdU^+ve/Iba1^+ve cells. Scale bar corresponds to 50 µm. C The density of Iba1^+ve microglia is similar between genotypes. D Fewer EdU^+ve cells/mm² were observed in the corpus callosum of Mertk cKO mice (P = 0.042), with a significant reduction in Edu^+ve cells at P28 (P = 0.0462). E Microglial proliferation was not altered in the absence of Mertk. Data represent mean ± SD. Statistical significance determined using 2-way ANOVA with Fisher’s LSD