Figure 2.

Vasculogenesis and the brain histology of Cld5 ^−/− mice. (a and a′) Whole-mount immunostaining. Mouse 9.5-d wild-type and Cld5 ^−/− embryos were labeled with anti–PECAM-1 mAb. The characteristic treelike and ladderlike staining patterns of blood vessels in the head and vertebrate portions were observed both in wild-type and Cld5 ^−/− embryos. (b, b′, c, and c′) Hematoxylin-eosin–stained paraffin sections (b and b′) and anti–PECAM-1–stained frozen sections (c and c′) of the wild-type and Cld5 ^−/− brains of 18.5-d embryos. No difference was detected. Bars: (a and a′) 300 μm; (b and b′) 100 μm; (c and c′) 40 μm.