Figure 2.

Different temporal plasticity of mouse cortical and spinal microglial heterogeneity

(A) The temporal profiles of cortical microglial subtypes in two-, four-, and eight-month-old Wt mice. HOM-M were polarized into HOM-M1 and HOM-M2 at all ages. HOM-M2 displayed with a characteristic down-regulation of genes including Rps11, Rps21, Rpl26, Rgs10 (blue boxes) genes coding for ribosomal protein and regulator of G protein signaling. IFLAM-M subtype was a small subtype of cortical microglia identified at two and four months but not at eight months. A subtype of interferon related microglia (INF-M) appeared at 8 months. The highly expressed genes in specific clusters are indicated in pink boxes. We only highlighted genes upregulated (red) or downregulated (blue) in the corresponding clusters compared to HOM-M1.

(B) The temporal profiles of spinal microglial subtypes in two-, four- and eight-month-old Wt mice. IFLAM-M were segregated into two sub-clusters (IFLAM-M1 and IFLAM-M2) at 4 months with their specific set of upregulated genes (pink boxes). At eight months, a small microglial cluster expressing genes regulating cell cycle and proliferation (PLF-M) appeared.

(C) Quantitative differences of cortical and spinal microglia expressing specific inflammation-related genes at different ages. Spinal microglia had a markedly higher portion to express a set of inflammatory regulatory genes than cortical microglia, at all ages checked. See also Figures S3–S5.