Cell transformation by the left terminal regions of the adenovirus 40 and 41 genomes

To study the transforming capacity of the two fastidious adenoviruses 40 and 41 (Ad40 and Ad41), we have cloned the left terminal regions of their genomes. Transfection with plasmids containing these regions leads to transformation of primary baby rat kidney (BRK) cells. Cell lines derived from transformed cells show an intermediate transformed phenotype. The left terminal region was present in at least 50 copies in cells transformed by Ad41 and in 2–3 copies in Ad40-transformed cells. The integration patterns of the plasmids containing the left terminal region of Ad41 were similar in three different cell lines.