Fig. 4.
Daily but not total mitotic output of hair-follicle matrixes is under circadian regulation. (A and B) Proliferative Pcna-positive cell population is expanded distally above the Auber line in Cry1−/−;Cry2−/− and induced K14creER;Bmal1f/f anagen hair follicles compared with WT. Ectopic Pcna-positive cells in circadian mutants maintain strong Per2 expression (B). (C and D) Total length of dorsal guard and zigzag club hairs in adult Cry1−/−;Cry2−/− mice does not differ significantly from these in WT mice. (E and F) A large proportion of ectopic Pcna-positive cells in precortex of Cry1−/−;Cry2−/− hair follicles coexpresses markers of differentiation: pSmadD1/5/8 (E vs. F) and Lef1 (G vs. H). [Scale bars: 50 µm (A, B, and E–H); 2 mm (C and D).] Also see Figs. S8 and S9.