Figure 2. Replication of MVMp and H-1PV in human transformed or tumor cell lines.

HEK293 and HEK293T (A), NB324K (B) and Hela (C) cells were mock-treated or infected with MVMp or H-1PV at 5 PFUs/cell. At the indicated time post-infection (p.i.) cells were harvested and DNA was extracted according to a modified Hirt procedure (see Materials and Methods). Samples were then digested with proteinase K and 2 µg of DNA from each sample was then subjected to eletrophoresis through a 0.8% agarose gel and further transferred by capillarity on a Hybond-N membrane. Expression of DNA intermediates was investigated using a mixture of radiolabeled DNA probes corresponding to the Eco RI-Eco RV and Hind III-Hind III fragments of the viral NS genes from MVMp and H-1PV, respectively. Assessment of the migration of MVMp isolated genomes (0.08 µg) was used in each blot as migration control of the different DNA intermediates; mRF, monomeric replicative form; dRF, dimmer replicative form; ssDNA, single-stranded genome. The blots shown are representative of 3 experiments which all gave similar results.