FIG. 7.

B1 is not required for late gene expression. L929 cells were transfected with p11K-CAT alone or with three plasmids (pT7-A1L, pT7-A2L, and pT7-G8R) that express VLTFs regulated by T7 promoters. The transfected cells were infected with ts25T7 at 32 or 39.5°C to provide T7 RNA polymerase. CAT activity was assayed at 24 h after infection and normalized to the value obtained for sample 1.