FIGURE 5: Cold exposure induces p53/p21-dependent G2/M cell cycle arrest. (A-B) (A) Representative pictures of KI67 IHC and (B) its quantification from liver sections of hURI^Hep mice exposed to RT or CT. (C) Western blot analysis of hURI^Hep mouse livers housed at RT or CT. (D) Cell number count of U2OS cells incubated for 24 hours at 27^◦C or 37^◦C [n=3]. (E) Representative image from bright field microscope of U2OS cells incubated for 24 hours at 27^◦C or 37^◦C. (F-G) Representative PI flow cytometry plots (F) and percentage of cell populations present at the different phases of the cell cycle (G). U2OS cells were incubated at 27^◦C or 37^◦C for 24 hours [n=3]. Statistical analysis was performed using Brown-Forsythe and Welch ANOVA (B), two-way ANOVA (D), and unpaired two-tailed Student’s t-test (F). Unless otherwise indicated, data are represented as mean ±s.e.m from n independent experiments; *P ≤ 0.05****P ≤ 0.001. Scale bars 100 µm (A).