Fig. 1: scRNA-Seq of lumbar spinal cord microglia.

a–d scRNA-Seq PCA scatter plots of lumbar spinal cord YFP (+) cells of adult Cx3cr1-creER-yfp /+; +/+ heterozygous animals at different timepoints after sciatic nerve injury. The vast majority of microglia in naive animal were in G1 phase of the cell cycle (a), a substantial portion of microglia 1 day after nerve injury were in S phase of the cell cycle (b), and many microglia were in G2/M phase of the cell cycle 2 days (c) and 3 days (d) after nerve injury. Note that the S-phase cells appeared one day (b) before the appearance of G2/M-phase cells (c), and the distribution patterns of S phase cells were different between 1 day (b) and 2 days (c) after nerve injury. The distribution patterns of G2/M phase cells were also different between 2 days (c) and 3 days (d) after nerve injury. e Proportion of microglia cells expressing Myc or Mki67 from scRNA-Seq analysis. Myc was expressed in a higher proportion of microglia 1 day after nerve injury, and Mki67 was expressed in a higher proportion of microglia 2 days after nerve injury. f Violin plot of scRNA-Seq showing that a cluster of microglia transiently increased Myc expression on day 1 after nerve injury, and the expression returned to baseline by day 2. g, h qRT-PCR of sorted microglia from the lumbar spinal cord of adult Cx3cr1-creER-yfp/+; +/+ animals (g) and qRT-PCR of RiboTag enriched microglia mRNA from lumbar spinal cord (h). Myc was transiently upregulated in the ipsilateral lumbar cord microglia on day 1 after nerve injury, and the expression returned to baseline by day 2 after nerve injury. Analyses are two-way ANOVA with Sidak’s multiple-comparison test, n = 4–6, means ± SEM, ****P < 0.0001; ns, not significant.