Figure 4.

Detection of genetic changes in post-cell fusion cells and a proposed model of cell fusion in tumor progression (a). Ten single cell clones including 2 pS-puro-scrambled (clones 1-2), 2 pEYFP-N3-neo (clones 3-4), and 6 pS-puro-scrambled-pEYFP-N3-neo double selected clones (clones 5-10) were selected at random and amplified in cell culture. Genomic DNA was extracted from the cells. AmpFlSTR Identifiler PCR Amplification kit was used to examine microsatellite markers. Shown are fragment analysis of the D19S433 alleles. Note the fragment height of allele a (in the red box) was decreased in the fusion cells (6-9), and lost completely in clone #10 (b). A proposed model of K type human endogenous retrovirus in mediating intercellular fusion, evolution of genetic changes, and malignant progression