FIG. 2.

The tsD5 viruses exhibit a temperature-sensitive reduction in the production of infectious virus during a single round of infection. Confluent 35-mm dishes of BSC40 (A) or L929 (B) cells were infected with the WR (wt, Cts17, Cts24, and Ets69) (left graphs) and IHD-W (wt, Dts12, Dts56, and Dts6389) (right graphs) strains at an MOI of 2 and incubated for 24 h at either 31.5°C or 39.7°C. The yield of cell-associated virus was quantitated by titration on BSC40 cells at 31.5°C. The dashed line denotes the amount of infectious virus made during a wt infection at 31.5°C. Each infection was performed in duplicate, and each assay was titrated in duplicate. Error bars denote standard deviations.