Figure 4. Outer root sheath (ORS) analysis in Msx2-Cre; KrasG12D mice.
(a–c) Histology of postnatal day 10 (P10; anagen), P16 (catagen), P21 (early anagen) of wild-type and Msx2-Cre; KrasG12D hair follicles. (d) P10 analysis of hyperplastic ORS in Msx2-Cre; KrasG12D mice reveals irregular patterns of keratin 14 (K14)-positive, Sox9-positive ORS growth. (e) Apoptosis of P16 wild-type and Msx2-Cre; KrasG12D hair follicles as detected by phosphorylated histone H2A variant X (H2AX) staining (green, arrows). (f) Immunofluorescence reveals persistent and abundant secondary hair germ and ORS in telogen of Msx2-Cre; KrasG12D mice. Solid bracket indicates SOX9-positive cells in the region of the bulge. Dotted line indicates boundary of secondary hair germ in wild-type and of remnant ORS tissue in Msx2-Cre; KrasG12D mice. Black scale bar (a–c) = 100 μm; white scale bar (d–f) = 50 μm.