Panel A shows confocal microscopy images from wild-type mice, with immunostaining against VGluT1 in blue, Iba1 in white, and C3 in green. Panel B shows similar microscopy images from CD47 knockout mice. Insets a and b provide higher magnification images within microglia, highlighting C3 and VGluT1 in a and b, Iba1 in a double prime and b double prime, and merged images in a triple prime and b triple prime. Yellow arrows indicate tagged VGluT1-C3 residues. Panel C is a bar graph quantifying the percentage of microglia containing VGluT1-C3 residues. The y-axis represents the percentage, and the x-axis shows different mouse genotypes: WT, C3 minus slash minus, and CD47 minus slash minus. The graph indicates that WT mice have a higher percentage of microglia with VGluT1-C3 residues compared to CD47 minus slash minus mice, with statistical significance noted.
Microglia engulfment of VGluT1 synapses tagged by C3. (A and B) Single optical plane confocal images showing immunostaining against VGluT1+ (blue), Iba1 (white), and C3 (green) in WT (A) and CD47−/− (B) mice (scale bar for A and B: 10 μm). Insets a and b (red rectangles) depict higher magnification images within microglia. a′ and b′: show C3 (green) and VGluT1 (blue), a″ and b″: Iba1 (white), and a‴ and b‴: show the merged image. Yellow arrows indicate tagged VGluT1-C3 residues. Scale bar for insets: 1 μm. (C) Quantification of percentage of microglia containing VGluT1-C3 residues. Analysis performed from sampled microglia within the motor neuron area. WT, N = 3 mice; CD47−/−, N = 3 mice. *P < 0.05; ns: no significance; one-way ANOVA with multiple comparisons using Bonferroni’s test.