Fig. 3.
Increased size and cell proliferation in anagen HFs of p27Kip1 knockout mice. Dorsal skin of 12-week-old WT and p27Kip1 knockout (−/−) mice was harvested 12 days after depilation. Skin cryosections were processed for either histoenzymatic visualization of alkaline phosphatase (A and B) or immunofluorescent stainings with anti-Ki-67 antiserum (C and D). Histomorphometric analyses of the HFs and plucked hairs were performed (E and F). Statistical analysis was performed by using Student's t test, ∗, P < 0.05. (A and B) Anagen VI HFs in p27Kip1 −/− mice (arrows) and WT mice. (C and D) Proliferating cells in the matrix (arrows) and ectopic appearance of Ki-67 in differentiating cells above the FP (arrowhead) in the HF of p27Kip1 −/− mice. (E) Decrease of small HFs and increase of intermediate HFs in p27Kip1 −/− mice. (F) Increase in number of medulla cells in awl hairs of p27Kip1 −/− mice.