Figure 5.

Retinal vascular development in pdgf-b^ret/ret mice. Retinal vessels in control (pdgf-b^ret/+) and pdgf-b^ret/ret mice at P5. EC, isolectin (green); pericytes, NG2 (red); pericyte nuclei, XlacZ4 (dark blue, arrows). Peripheral (a,b) and central (e,f) regions in pdgf-b^ret/+ mice show formation of regular vascular plexuses. Note extensive coverage with pericytes (b,f), except for sprouting tips (b). In pdgfb^ret/ret mice, plexus spreading is delayed (c; peripheral), and irregular (g; central) with regions of hyperfusion (g, arrow), and reduced pericyte density (d,h). Peripheral (i-l) and central (m-p) regions at high magnification show that peripheral sprouting is sparse in pdgfb^ret/ret mice, leading to a wide-meshed, irregular vasculature partially devoid of pericytes. Few pericytes are present on remodeling arteries (cf. n and p, arrows).