Fig. 4From: Karyotype alteration generates the neoplastic phenotypes of SV40-infected human and rodent cellsKaryotypes of the immortal cell lines F1 and F4 derived from a common culture of SV40-infected human mesothelial cells. To test, whether the karyotypes of F1and F4 would explain the individual but related phenotypes of F1 and F4, we compared their karyotypes. The karyotypes were prepared from metaphase chromosomes stained with chromosome-specific fluorescent colors following published procedures (Methods). As shown in (a), F1 has a hyper-diploid, aneuploid karyotype with 56 including 36 normal and 20 marker chromosomes. The karyotype shown in (b) indicates that F4 has a hypo-tetraploid karyotype with 81 including 56 normal and 25 marker chromosomes. However, a close comparison of the copy numbers of the ten F1-chromosomes, 2, 5, 10, 11, 12, 15, 18, 19, 20 and of one shared marker chromosome (the first on the list of marker chromosomes), with their F4-counterparts reveals that the F1-copy numbers are exactly duplicated in F4. This suggests that F4 probably originated from F1 by some form of karyotype duplication (see text)Back to article page