Figure 8

A schematic model of copy number evolution. At an early stage of cell line establishment, cells that acquired ‘advantageous’ copy number changes would be selected due to the dosage effect of potential driver genes. We suggest that these included increased copy number for anti-apoptosis, or pro-survival genes as well as decreased copy number of pro-apoptotic or tumor suppressor genes. Further culture passages selected cells with more optimized genome structure that restored genic stoichiometric imbalance caused by drivers and especially passenger copy number changes.