Figure 2.

Effects of MYC Activation on SG Proliferation and Differentiation

(A–Q) WT and K14MycER (Myc:) mouse telogen back skin was untreated, acetone-treated (vehicle), or 4OHT-treated, as indicated. (A, D, F, H, and L) Skin sections were stained with H&E. (B, E, G, I, and M) Skin sections were stained with the antibodies shown. White bracket indicates expansion of AR-expressing sebocytes in (I). (C) Quantitation of SG differentiation compartment (average cross-sectional area occupied by differentiated sebocytes per SG) for the experiment described above. Red line represents average untreated WT measurement, and dashed red lines represent SEM. (J) Quantification of average size of individual differentiated sebocytes (cross-sectional area). (K) Average number of differentiated sebocytes per SG cross-section. (N) Quantitation of Ki67+ve sebocytes per SG. Red line represents untreated WT measurement. (O and P) qRT-PCR of Ki67 and Nucleolin mRNA levels relative to Gapdh. (Q) Schematic summary of changes relative to WT SG of treating K14MycER mice with low or high dose 4OHT. See Figure 1N for stages in sebocytes differentiation. Increases in cell number are represented by +, ++, or +++, according to the strength of the effect. Reduction in cell number is represented by −.

Three to nine mice were examined per condition. Error bars represent SEM #p < 0.06, ^∗p < 0.05, ^∗∗p < 0.01, and ^∗∗∗p < 0.005. Scale bars 40 μm. See also Figure S2.