Association of Adenovirus Type 12 Deoxyribonucleic Acid with Host Cell Chromosomes

Preparations of purified (3)H-labeled adenovirus type 12 ((3)H-Ad. 12) were analyzed for radioactive impurities by Millipore filtration and ultracentrifugation. It was found that only about 1% of the isotope activity was separable from the virions. Exposure of hamster cell lines to (3)H-Ad. 12 resulted in nonlytic infections, and autoradiography indicated that viral deoxyribonucleic acid (DNA), or parts thereof, became associated with host cell chromosomes. Usually, the label was observed in the form of small clusters of grains, as described previously for lytic adenovirus infections of human embryonic kidney cells. The uptake of labeled virus by the PT-K1 line of ratkangaroo cells was close to background level. These cells did not adsorb the virus to any significant extent. Ultraviolet irradiation of the virus for as long as 8 min did not affect viral adsorption onto susceptible cells, nor did it alter the association of viral DNA with host cell chromosomes. The capacity of the virus to induce chromosomal aberrations decreased linearly with an increase in the dose of irradiation, but the decrease occurred at a rate which was four- to fivefold slower than the rate of inactivation of viral infectivity. These results suggest that the capacity to induce chromosomal aberrations is controlled by viral genes.