Vascular defects in perlecan-null embryos.

(A) Schematic view of the region of the forebrain shown in (B–E). (B–C) Nissl stained coronal sections of E12.5 forebrain: the cerebral microvasculature is tightly embedded into the neuronal tissue of E12.5 wild type embryos (B); the perlecan-deficient vessels are dilated and loosely incorporated in the tissue (C). (D–E) Laminin immunostained BMs of neuroepithelium and blood vessels in ventral forebrain sections. A region with a blood leakage in a mutant embryo is shown (arrow in E). (F–G) Whole-mount picture of wild type (F) and perlecan mutant (G) at E17.5. Hemorrhages (arrow in G) and edema in the skin is evident in the mutant embryo. (H–I) Hematoxilin and eosin staining of the skin sections of E16.5 embryos. The skin of the perlecan-null embryo shows increased interstitial spaces (arrowheads) and dilated vessels (arrow). Bars: (B and C) 125 µm; (D and E) 40 µm; (H and I) 50 µm.