抄録
Bovine adenovirus type 3 (BAV3) causes abortive infection and induces cellular DNA synthesis in the mouse cell line, C3H2K.
A clone, N-1, was selected from this cell line after infection with BAV3 in the presence of 5-fluorodeoxyuridine. In this clone, cellular DNA synthesis was not induced by BAV3 infection, but became inducible in N-1 cells when the temperature of the culture was raised to 41°C-42°C prior to infection by BAV3. Heat-activated N-1 cells again became insensitive to BAV3 infection after prolonged cultivation at the normal temperature of 37°C. The addition of cycloheximide did not prevent activation of N-1 cells by heat, but it did prevent the activated N-1 cells from returning to their original state of being insensitive to BAV3 infection when cultivated at 37°C. Viral mRNA synthesis, which was followed by the induction of cellular DNA synthesis, was transiently detected only when N-1 cells were heat-treated before virus infection. Penetration into the cell and the uncoating of BAV3 proceeded in N-1 cells almost as normally as in C3H2K cells. Though the N-1 clone was selected by a procedure involving BAV3 infection, N-1 cells did not contain a detectable amount of the BAV3 DNA sequence as determined by analysis of DNA-DNA reassociation kinetics. The significance of these results is discussed.
