Figure 5

Prx1-Cre; Itβ1^flox/flox mice exhibit normal hair follicle morphogenesis and post-natal cycling. A: Mixed littermates (Ctrl) and Prx1-cre; Itβ1^flox/flox (Itβ1 KO) mice at 1 day post-natal (P1). Conditional knockouts display slightly reduced size and a reddened appearance on ventral and lateral surfaces. B: Representative H&E stained skin sections from the ventral skin over the sternum of P1 control and conditional knockout mice. C: Control and conditional knockout mice at 5 days post-natal (P5) showing the reduced size and reddened ventral skin of mutant mice. D: H&E stained skin sections from the ventral skin of P5 control and conditional knockout mice showing hair follicles in advanced stages. E: Quantitation of hair follicle stages in P1 and P5 control and conditional knockout mice showing similar patterns of hair development. F: Control and conditional knockout mice at 82 days showing the normal appearance of coat on the ventral and lateral regions. G: Immunofluoresence for p75 (green) and Itβ1 (red) in sections of ventral skin from P1 control and conditional knockout mice at P1 (as indicated). Brackets indicate p75+ dermal papilla. Note lack of Itβ1 signal in the dermal papilla of a Stage 4 hair follicle (arrow). H: Immunofluoresence for mouse LM511 (green) shows normal incorporation of this laminin in P1 control and conditional knockout mice. Scale bars represent 20 μm. Abbreviations: Ctrl, control; Itβ1 KO, dermal Itβ1 knockout; HFs, hair follilces.