(A) Identification of differentially expressed TF targets across microglia development. Gene targets regulated by TFs experimentally annotated in TRANSFAC (detailed in Methods), Z-scores heatmap of the gene targets of 18 TFs (YS = Yolk Sac, BR = Brain Rudiment, N = Neonate, A = Adult). (B) Gene targets regulated by Irf8, Pu.1 and Rela according to experimental annotations in TRANSFAC database (detailed in the Methods section). Targets differentially expressed in Psen1KI/KI vs WT (FDR<0.1) are color-coded with respect to each developmental stage where such differential expression is observed. (C) Quantitative RT-PCR of the most differentially expressed TFs targets in Psen1KI/KI vs WT. Pu.1 targets are H2-Ab1, Mpo, Aif1 and H2-Ab1 (YS, BR, Neonate and Adult respectively), Irf8 targets Il18 (YS, BR and Neonate) and Cd36 (adult), Rela targets Il1b, Bmp2, Tlr2 and Ngb. (YS, BR, Neonate and Adult respectively). (D) Quantitative RT-PCR of Pu.1 and Csf1r in microglia from brain rudiment. Bar plots represent means ± sem. *p < 0.05, **p < 0.01, ****p < 0.0001, 2 sample t-test. For microglia progenitors, N = 3–4 biologically independent measures from 6–12 pooled yolk sacs or brain rudiment. For neonate and adult microglia, N = 4 animals per group.