Fig. 4

a Volumetric views of wild-type 5 dpf larval brain showing microglia (arrows) using the mpeg1:GFP transgene as cells depth-coded from most ventral in magenta to most dorsal in cyan. See corresponding z-stack data in Supplementary Movie 4. Left, dorsal surface at z = 220 μm shows the tectum, cerebellum, and hindbrain (hb). Right, more ventral view at z = 160 μm shows the telencephalon (tele) and diencephalon (dien). b Volumetric views of a z-stack from two axial levels (z = 60 μm and 115 μm) of a wild-type double transgenic zebrafish at 5 dpf showing microglia (GFP+) intimately intermingled with neurons (dsRed+) throughout the larval brain. See corresponding z-stack data in Supplementary Movie 5. c Diagram depicting microglia and peripheral macrophage status in wild-type and four distinct microglia-lacking mutants in larval zebrafish. d Characterization of the four mutants (nlrc3l^−/−, irf8^−/−, xpr1b^−/− and pu.1/spi1b^−/−) by neutral red staining shows an absence of microglia, and by bright-field transmitted microscopy shows normal gross morphology with large swim bladders indistinguishable from wild-type. Locomotor behavior tracking in the 96-well platform analyzing irf8 mutants (e), xpr1b mutants (f), and pu.1/spi1b mutants (g). One-way ANOVA tests followed by multiple comparisons were used to determine statistical significance; individual p-values shown; locomotion from d2-d4 was analyzed; ns, not significant. See also associated Supplementary Movies 4 and 5.