Fig. 1

Expandable microglia generation from the embryo neuroepithelial layer. A Mouse head neuroepithelial layer (NEL) was dissected at E13.5 and was cultured for 21 days (d). B Microglia progenitors proliferated and ramified over time. C IBA-1⁺Ki67⁺ cells were stained and the ratio of IBA-1⁺Ki67⁺ cells/IBA-1⁺ cells increased over time. The number of PU1- and F4/80-positive cells also increased with the progression of the culture. TMEM119 was stained weakly at 21 d. Scale bar = 100 μm. Proliferative microglia (IBA-1⁺Ki67⁺ cells) were counted using microscopy. Sampled areas were selected randomly from 100 × fields in three independent experiments. A post hoc test was conducted using Tukey’s multiple comparison tests. **p < 0.01, ***p < 0.001 compared to 1 d, ^#p < 0.05 compared to 7 d