Ploidy Reductions in Murine Fusion-Derived Hepatocytes (original) (raw)
Figure 5
Potential mechanisms for diploid hepatocyte formation from polyploid fusion-derived hepatocytes.
(A) Cytokinesis without mitosis. A binucleated cell undergoes cytokinesis before entering the next cell cycle. This process would not produce marker loss or aneuploidy. (B) Multiple spindles, followed by multipolar (in this case tetrapolar) mitosis. Extreme aneuploidy would result. (C) Mitosis without S-phase with chromosome pairing. This would ensure proper chromosome segregation and would facilitate distribution of hemizygous markers between daughter cells. (D) Horizontal gene transfer. A diploid cell engulfs a neighboring cell undergoing apoptosis. Single chromosomes and/or chromosome fragments would be incorporated into the nucleus while maintaining a nearly diploid karyotype. The parental cell is shown at left, mitotic spindle(s) (when necessary) in the middle and resulting diploid cells on the right. Open circles represent centromeres. Black circles represent centrosomes. Chromosomes are shown in different colors to indicate their lineage. Host hepatocyte chromosomes are red, and donor chromosomes are blue.