Fig. 4

xMG resemble their localization in the chimeric mouse retinal explants. (A) Schematic of the experimental design and procedures. Pregnant mice were fed PLX5622, and the neonatal mice were further injected with PLX5622 for 4 days. Explants transplanted with human iPSC-derived microglia (iMG) were cultured for 7 days. (B) Representative images of retinal whole mounts with anti-Iba1 immunostaining. Enlarged images show the co-labeling of EGFP (green) and Iba1 (purple). Scale bars, 500 μm and 50 μm in the original or enlarged images, respectively. (C) Quantitative analysis of replacement efficacy. Ratio of xeno-transplanted human microglia (xMG) to mouse endogenous microglia (mMG) in mouse retina explants. n = 4 retinas. (D) Representative 3D images (top view and side view) of image stacks showing xMG distribution at different layers in mouse retinal explants at 7 days post-transplantation. ONL: outer nuclear layer; OPL: outer plexiform layer; GCL/IPL: ganglion cell layer/inner plexiform layer. (E) Representative images from GCL/IPL, OPL, and ONL showing xMG (arrows indicated) morphology in mouse retinal explants. Scale bars, 50 μm. (F) Quantifications of xMG cell density in mouse retina explants. n = 4 retinas. (G) Schematic of the antibody (anti-IL34) blocking experiment procedures. (H) Quantification of xMG cell density in IPL, GCL, and OPL of mouse retinas in control and anti-IL34 treated groups. n = 3 retinas