FIG 2.
Deletion of ORFs 212tr to 216 impaired the virulence of CL3. (A) Major ORF differences between ACAM and CL3 are shown. Arrows indicate relative lengths of ORFs and the direction of transcription. ORFs are colored green for ACAM and ORFs, and parts of ORFs of CL3 that are unique are colored yellow. Note that C12 of ACAM, depicted as a green arrow, is truncated and called 212tr, whereas C12 of CL3, depicted as a green arrow with a yellow arrowhead, is full length and called C12FL. The diagram of CL3-Δ212tr-216-Luc-GFP shows a truncation of C12 and replacement of ORFs 213 to 216 by GFP regulated by the VACV P11 promoter, in blue. (B) CAST mice (n = 5) were infected i.p. with 106 PFU of ACAM-Luc, CL3-Luc, or CL3-Δ212tr-216-Luc-GFP. The progress of infection was measured by injecting d-luciferin and measuring luminescence. Ventral-view images of mice are shown for day 3 and day 5 after infection. (C) Total photon flux of the body of each mouse was calculated and shown by group. Bars indicate arithmetic means ± SD. ****, P < 0.0001. Significance was calculated using Fishers exact test.