Figure 1.

Construction and plaque formation of VACV mutants with deletion of the dUTPase gene and active site mutations in the uracil DNA glycosylase gene. (A) Schematic diagram of the VACV genome organization. The WR genome is represented with expansions showing replacement of F2L gene with RFP in vΔF2 and vΔF2d4 and D68N and H181L point mutations (indicated by asterisks) in D4R gene with adjacent green fluorescent protein gene in vd4 and vΔF2d4. (B) Plaques of WR, vd4, vΔF2, and vΔF2d4 on BS-C-1 cells. Viruses were plated on BS-C-1 cell monolayers and covered with a semi-solid methylcellulose overlay. After 2 days at 37°C, the monolayers were stained with crystal violet.