Fig. 5

Comparison of the karyotype arrays of the immortal F1 and F4 lines from SV40-infected human mesothelial cells. Karyotype arrays are three-dimensional tables of 20 karyotypes, which list the chromosome numbers of each karyotype on the x-axis, the copy numbers of each chromosome on the y-axis, and the number of karyotypes arrayed on the z-axis, as detailed in the text (Section I, Phenotypes and karyotypes of neoplastic clones from SV40-infected mesothelial cells). a and the attached table shows that the F1 line is hyper-diploid, consisting of 56 chromosomes that are 70 % to 100 % clonal. Accordingly the F1-chromosomes formed a quasi-clonal F1-array, which defines the F1 line. The non-clonal fraction of chromosomes included several partially clonal and several non-clonal marker chromosomes, indicative of ongoing karyotypic variation (see Fig. 1). b shows the F4 line is hypo-tetraploid consisting of 83 chromosomes which are 60–100 % clonal. Accordingly the F4-chromosomes formed a quasi-clonal F4-array, which is distinct from, but visibly related to that of the F1 line. The attached tables indicate that the differences between F1 and F4 include 19 F1-specific and 13 F4-specific clonal marker chromosomes. The tables also indicate that the copy numbers of 10 intact and one F4 marker chromosomes were exact duplications of the copy numbers of the corresponding F1-chromosomes (marked yellow in Fig. 5). In addition F1 and F4 shared two nullisomies of chromosomes 7 and 13. Moreover, several F1-chromosomes with non-duplicated copy numbers in F4 were increased in F4, but not exactly two-fold. This result thus indicates that the F4 line is a descendant of the F1 line generated by some form of tetraploidization (see text), rather than an independent clone