Figure 3.

Hepatocytes from E2f7/E2f8-deficient livers were predominantly euploid. Hepatocytes isolated from control or liver-specific E2f7/E2f8 double knockout (LKO) mice (male) were cultured briefly to stimulate cell division, proliferating hepatocytes were arrested in metaphase, and chromosomes from individual cells were identified by G-banding. A: Representative karyograms are shown for control and LKO hepatocytes. Chromosome name (ie, 1 to 19, X, and Y) and number (listed in parentheses) are indicated. Chromosome losses are marked in blue, and chromosome gains are shown in red. The example control hepatocyte was tetraploid and aneuploid with 80 chromosomes (four copies of most autosomes and two copies of each sex chromosome) but lost one copy of chromosomes 3 and 17 and gained one copy of chromosomes 5 and 13. The example LKO hepatocyte was diploid and euploid (two copies of all autosomes and one copy of each sex chromosome). B: Chromosome number is shown for control and LKO hepatocytes. Skewed chromosome counts (eg, hypodiploid, hypotetraploid, and hypertetraploid) were frequent in control but not LKO hepatocytes. C: Chromosome (Chr) gains and losses were summarized relative to the euploid number of homologous chromosomes. Every row marks an individual cell, and each column corresponds to a different chromosome. Detailed karyotypes are provided in Supplemental Tables S1 and S2. D: The percentage of aneuploid hepatocytes is indicated. Data are expressed as means ± SEM (D). n = 4 mice per genotype (B–D); n = 14 to 20 cells per mouse (B–D); n = 68 control hepatocytes (B–D); n = 80 LKO hepatocytes (B–D). ^∗∗∗P < 0.001.