Fig. 4.

Dynamic molecular expression in dermal components during feather cycling. (A) Brightfield view of the plucked proximal feather follicle at different regeneration phases. (B) PCA analysis of RNA-seq showing the pulp at different growth phases and during the resting-phase aDP. (C) DEG clustering analysis and the expression heat map. (D,E) Expression level of signaling molecules (D) and ECM (E) in different pulp formation stages. Data are mean±s.d. (F,H) In situ hybridization of CDK1 (F) and SOSTDC1 (H) in different pulp developmental stages. Red arrows indicate the expression in pPP (growth phase) and aDP (resting phase). (G) Immunostaining of COL2A1 (red) and MMP9 (green) in different pulp developmental stages. Boxed areas are shown enlarged in the lower panels. The separated green and red channels are shown in Fig. S4. aDP, apical dermal papilla; bDP, basal dermal papilla; cPP; central pulp; DP, dermal papilla; DS, dermal sheath; EG, early growth phase; LG, late growth phase; NR, near resting phase; pPP, peripheral pulp.