Host-range phenotype of DV2 mutants. Titers for the WT DV2 and mutant viruses are shown. All virus strains were grown in Vero (mammal; black bars) and the C6/36 (insect; gray bars) cells to measure host-range phenotype. The titers of the mutant viruses were determined by a fluorescent focus assay. Titers of WT virus were measured by a colorimetric focus assay. DV2ΔIGV did not display the host range phenotype and DV2ΔG was a host range mutant which grew better in the Vero cells. Only DVΔGVII and DVΔLIG were chosen for further analysis.