Figure 1.

The HCMV IE1 and IE2 genes cooperate with the adenovirus E1A gene to transform primary BRK cells. (A) Representative BRK transformation assay showing the number of foci that arise in response to transfection with different combinations of expression plasmids. (B) BRK transformation assays demonstrating that IE1 plus IE2 cooperate with E1A for transformation. The number of foci reported is the total from 10 plates assayed in four independent experiments. (C) Representative experiment showing that IE1 and IE2 cDNAs cloned in an antisense orientation (αIE1 and αIE2) have no transforming activity. The number of foci reported is the total from three 100-mm plates. In all experiments, the gene products expressed by transfected plasmids are listed below the bars. Cultures transfected with pCGN containing no insert are designated vector.