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Fig. 6. Following the caudal to rostral and deep to superficial development of the
whisker pad vasculature (E), embryonic microvascular endothelial cells of the
whisker pad only express the ß4 integrin subunit in the caudal and deep
vasculature in the whisker pad from an E19.5 p.c. animal. Sections from the
caudal region (A,B) are shown immunostained with s100 (green) and either MEC
13.3 to PECAM-1 (A: red) or with 346-11A to ß4 (B: red). Neighboring
sections from a more rostral region are shown immunostained with MEC 13.3 to
PECAM-1 (C) or 346-11A to ß4 (D). The majority of the vasculature was
ß4 negative, however, some larger caliber vessels deeper in the tissue
were ß4 positive (arrowheads). (E) Schematic representation of the
whisker pad showing six whisker follicles along the caudal to rostral axis,
where the filled arrowhead indicates a whisker and the open arrowhead
indicates a hair follicle. Intense ß4 labeling is present on basal
keratinocytes of the epidermis (e), hair follicles (f) and whisker follicles
(wf). Scale bars: 100 µm.