Centrosomal γ-tubulin levels correlate with cell-cycle status and not differentiation state. (A) Immunofluorescence localization of γ-tubulin in WT epidermis and epidermis expressing active Notch (NICD). (B) Quantification of the ratio of centrosomal γ-tubulin in basal cells versus underlying dermal cells (n = 2 control and NICD mice). (C) Quantification of γ-tubulin centrosomal localization from basal cells to terminally differentiated superficial cells. (D) Immunofluorescence localization of γ-tubulin in WT epidermis and α-catenin–null epidermis. (E) Quantification of the ratio of centrosomal γ-tubulin in basal cells verses underlying dermal cells (n = 2 control mice and n = 2 KO mice). (F) Quantification of γ-tubulin centrosomal localization from basal cells to superficial cells (n = 2 control mice and n = 2 KO mice). (G) Immunofluorescence localization of γ-tubulin in WT E15.5 and E17.5 epidermis. (H) Quantification of γ-tubulin centrosomal localization from basal cells and immediate suprabasal cells (n = 2 mice for each stage). Note that the data for the E17.5 mice are the WT data from the NICD mice in B. (I) Schematic of the epidermis showing the transition to a postmitotic state. n.s., not significant; *, P < 0.05; ***, P < 0.001. Data are presented as mean ± SEM. Bars, 10 µm. Dashed lines indicate the basement membrane.