Figure 3.

2/3 hepatectomy in transplanted Apc2^Δ/flox Mx-Cre mice causes metaphase arrest. (A) Cytospins of bone marrow cells at day 3 and day 4 after 1 × 400 μg pI/C injection. In the Apc2^Δ/flox Mx-Cre bone marrow, the number of mitotic cells (arrowheads) was increased at day 3 after pI/C. At day 4, only erythrocytes and a few mature lymphocytes could be detected in Apc2^Δ/flox Mx-Cre bone marrow. (B) Hematoxylin/eosin staining of Apc2^Δ/flox and Apc2^Δ/flox Mx-Cre livers 72 h after 2/3 hepatectomy in unaffected Apc2^Δ/flox Mx-Cre mice. In the Apc2^Δ/flox Mx-Cre mice, 70% of the hepatocytes were enlarged and 50% of the cells were in metaphase. (C) Squashes from Apc2^+/+ and Apc2^Δ/flox Mx-Cre livers 48 h after 2/3 hepatectomy. (a–g) Mitosis in Apc2^+/+ hepatocytes. (a) Prophase; (b) early prometaphase, NEB but no biorientation of chromosomes; (c) late prometaphase, not all chromosomes are aligned yet at the equatorial plate; (d) metaphase, sideview, all chromosomes were aligned at the equatorial plate; (e) anaphase, sister chromatids were segregating to opposite poles; (f) telophase; (g) early G₁. (h–l) Mitosis in Apc2^Δ/flox Mx-Cre hepatocytes. (h) Prophase, no difference from Apc2^+/+ hepatocytes; (i) prometaphase, the shape of individual chromosomes appeared ill defined; (j) prometaphase-like cell with condensed chromatin; (k) metaphase, polar view; (l) metaphase-like cell with condensed chromatin, but individual chromosomes could not be observed.