Figure 1.
Lifeact-EGFP is highly expressed in endothelial cells but practically absent from astrocytes in the postnatal retinas of Lifeact-EGFP mice.
IB4 (A in red), GFAP (B in red) or VECad (C in red) staining of whole-mounted P5 retinas. Lifeact-EGFP: green. Scale bars: A: 100 µm, B: 100 µm, C: 50 µm. af: angiogenic front; cp: central plexus; at: artery; vn: vein.
Figure 2.
Lifeact-EGFP expression is nearly absent in retinal tissue macrophages.
IB4 (in red) staining of whole-mounted P5 (A) and P10 (B) retinas. Lifeact-EGFP: green. Arrows point to IB4-positive tissue macrophages. Scale bars: 20 µm.
Figure 3.
Lifeact-EGFP is weakly expressed in the vascular mural cells of the retinal vasculature.
αSMA (A in red) or NG2 (B in red) staining of whole-mounted P5 retinas. Lifeact-EGFP: green. Arrows point to αSMA-positive cells (A) and NG2-positive pericytes (B). Scale bars: A: 50 µm, B: 20 µm and 50 µm.
Figure 4.
The skin and the cremaster muscle of Lifeact-EGFP mice are powerful systems to visualize F-actin of vascular mural cells.
CD31 (in red) staining of whole-mounted tail skin (A) and ear (C and E). Lifeact-EGFP: green. (B and D) αSMA (in red) and CD31 (in blue) double labelling of blood vessels in the cremaster muscle. Lifeact-EGFP: green. Arrows point to endothelium and arrowheads point to vascular mural cells. Scale bars: A: 100 µm, B: 100 µm, C: 20 µm, D: 15 µm, E: 100 µm. at: artery; cp: capillaries; hf: hair follicle; lym: lymphatic endothelium; m: muscle.
Figure 5.
Lifeact-EGFP colocalize with phalloidin.
Phalloidin (in red) staining of whole-mounted P6 retina. The leading edges of tip cells are highly enriched in actin filaments (arrows). Lifeact-EGFP: green. Scale bars: 10 and 50 µm.
Figure 6.
Lifeact-EGFP labels cortical actin, filopodia and cytoplasmic actin bundles in tip and stalk endothelial cells.
(A) Migrating tip cells. Arrows indicate tip cell filopodia, white arrowheads point to F-actin filaments in the cytoplasm and red arrowheads point to cortical actin. High-magnification deconvolution images of tip cell (B) and stalk cells (C) showing details of actin cytoskeleton organization (Lifeact-EGFP: green), with fine actin-rich filopodia protrusions and cortical actin cables, running along adherens junctions (VECad: red) (D) VECad (in red) and αSMA (in blue) double labelling of a vascular sprout. Lifeact-EGFP: green. Arrowheads indicate short actin filament protrusions in stalk cells. (E) Optical section of retinal vasculature stained with ICAM-2 (in red). Lifeact-EGFP: green. Arrowheads point to the luminal endothelial membrane and the asterisk marks the abluminal side of a vessel. Scale bars: A: 30 µm, B: 5 µm, C: 5 µm, D: 10 µm, E: 20 µm.