Fig. 3

Heterozygous ALSP-causing CSF1R missense variants act dominant negatively in reducing the number of microglia. a Schematic representation of csf1ra with the 20 bp gRNA and the PAM motif, and 5 base pair (bp) deletion in exon 17 indicated, resulting in a frameshift (green) followed by a premature stop codon. b Representative images of the midbrain (dashed line) after NR staining of progeny of csf1ra^A784V/+ crossed with csf1ra^ex17∆5/+ at 3 dpf. c Quantification of NR + microglia in the midbrain of csf1ra^+/+ (green, n = 23), csf1ra^A784V/+ (blue, n = 22), csf1ra^ex17∆5/+ (purple, n = 18) and csf1ra^{ex17∆5/A784V} (orange, n = 18). d Expression of csf1ra mRNA in WT, csf1ra^A784V/A784V, csf1ra^V614M/V614M and csf1ra^+/+ (n = 20/group) normalized to expression of eef1a1l1 (grey) and microglial gene mpeg1 (blue). e Expression of mpeg1 mRNA normalized to expression of housekeeping gene eef1a1l1 in WT, csf1ra^A784V/A784V, csf1ra^V614M/V614M and csf1ra^+/+. f Representative images of the midbrain (dashed line) after NR staining of progeny of csf1ra^A784V/+ crossed with csf1ra^V614M/+ at 3 dpf. g, h Quantification of NR + microglia in the midbrain at 3 dpf (g) and 5 dpf (h) in csf1ra^+/+ (green, n = 21, 18), csf1ra^A784V/+ (blue, n = 13, 14), csf1ra^V614M/+ (purple, n = 15, 13) and csf1ra^A784V/V614M (orange, n = 22, 15). Days-post-fertilization (dpf), neutral red (NR), wild type (WT). One-way ANOVA test was preformed to test for significance (p < 0.05). Error bars represent SD. *p < 0.05, ****p < 0.0001. Scale bars equal 200 μm