Chromosomal changes in bovine papillomavirus type 1-induced Syrian hamster tumors

Bovine papillomavirus type 1 (BPV-1) induced fibrosarcomas in the Syrian hamster were studied cytogenetically by G- and C-banding techniques. All tumor derived cells showed chromosome abnormalities that remained stable during serial tumor transplantations. Cells without chromosome abnormalities found in two cultures were derived from the host animals on account of heterochromatin polymorphisms. In most tumors pseudodiploid cells prevailed, some cells were hypodiploid lacking one or two chromosomes, and one tumor showed two hyperdiploid cell clones with one and three additional chromosomes, respectively. Some of the chromosome abnormalities apparently are nonrandom. Three chromosomes (#1, #4, and #15) were most frequently involved in aberrations.