FIG. 8.

The +55 HRE confers a selective disadvantage for replication in MA-134 cells, but not in CV-1P, TC-7, or Vero cells. Shown are sequence electropherograms of the +55 HRE 3′ half-site regions of PCR products generated from viral DNA recovered from the initial virus stock (starting) used for infection of CV-1P, MA-134, TC-7, and Vero cells with WT and +1 HRE MT in an initially equal, low-MOI coinfection and from the first and second harvests following sequential infection and incubation at 37°C for 10 days in DMEM containing 2% FBS. Virus competition experiments were performed in triplicate. The electropherograms shown here are representative of the data obtained from one set of experiments. For the significance of colors and of the vertical and horizontal rectangles, see the Fig. 3 legend.