FIG 2.

Growth and spread of UL51 deletions on Vero and HEp-2 cells. (A) Single-step growth of BAC-derived HSV-1(F), UL51-FLAG, and two independently isolated UL51 deletion viruses was measured on Vero cells. Stocks were prepared from the total infected culture (cells and medium). (B) Virus released into the medium during the single-step growth experiment shown in panel A. (C) Sizes of plaques formed by wild-type and mutant viruses on Vero cells. Plaque areas were measured 2 days following low-multiplicity infection as described in Materials and Methods. Each oval represents the area of a single plaque. Twenty plaques were measured for each virus. Note that the y axis has a logarithmic scale. (D) Same as panel C except that plaques were measured on Vero and UL51-complementing cells, as indicated below the graph. (G to H) Same as panels A to C except that measurements were performed by using HEp-2 cells. Note that the y axis in panel F has a linear scale. For replication and release measurements (A, B, E, and F), each point represents the mean of three independent experiments, and the error bars represent the ranges of values obtained. Statistical significance for replication and release experiments, where noted in the text, was determined by using a Student t test, as implemented in Microsoft Excel. Panels C and F are each representative of three independent experiments. The differences in plaque sizes between the HSV-1(F) BAC and the UL51 deletion mutants shown in panel G are significant, with P values of <0.01 determined by using a Kolmogorov-Smirnov test.