Increased bile duct reaction, apoptotic cells, dividing cells and mononucleate cells are evident in Cnot3−/− livers. (A-D) Immunohistochemistry for F4/80 (A) and CK19 (B), Masson's trichrome staining (C) and actin staining (D) of livers from 4-week-old (4 w) control and Cnot3LKO mice. Arrowheads and arrows in A indicate macrophages and those engulfing hepatocytes, respectively. Arrows in C indicate weak fibrotic regions. Magnified views of representative areas are shown in the inset in C. (E,F) Identification of cells with diploid (2c), tetraploid (4c) and octaploid cellular content (8c), corresponding to diploid, tetraploid and octaploid hepatocytes by FACS analysis of hepatocytes stained with PI. Representative profiles are shown in E. (F) Graph shows the percentage of each population quantified using FlowJo (n=5, 4 w). (G) The percentage of binucleate hepatocytes in 4 w control and Cnot3−/− livers (n=4, more than 350 cells were counted). (H) Immunohistochemistry for cleaved caspase 3 (top), Ki67 (middle) or pHH3 (bottom) in 4 w control and Cnot3−/− livers. Arrows indicate stained cells. Graphs show percentages of hepatocytes positive for each immunostaining. Five different fields (total of around 1000 cells) in each section were counted (n=3). Data are mean±s.e.m. Scale bars: 50 μm. **P<0.01, ***P<0.001.