Chromosomal aberrations and cloning efficiency in adenovirus type 12-infected hamster cells

The fate of hamster cells, abortively infected with adenovirus type 12, has been studied by correlation of chromosomal aberrations with induction of T antigens and cloning efficiency. The incidence of chromosomal changes paralleled to some extent the T antigen formation, but was inversely related to the cloning efficiency of the cells. At an input multiplicity of 100, within 24 hr after infection, nearly all of the cells or metaphases revealed the presence of T antigens and chromosomal lesions, respectively, but no clones of cells were obtained. Inhibition of cellular deoxyribonucleic acid synthesis was not noted during this period. Increasing doses of ultraviolet irradiation reduced, successively, the capacity of the virus to induce chromosomal aberrations and correspondingly improved cloning efficiency of the exposed cells. It is concluded that most, if not all, cells revealing chromosomal lesions 24 hr after infection fail to enter further mitoses.