FIG. 7.

Apoptosis of HeLa Tet-Off cells expressing genes encoding different fragments of VgrG1. Apoptosis rates were measured by quantification of cytoplasmic nucleosomes (A) and levels of caspase 3 and caspase 9 activity (B) in lysates of HeLa Tet-Off cells expressing vector alone (pBI-EGFP) or genes encoding NH₂- and COOH-terminal fragments and full-length VgrG1 from A. hydrophila ATCC 7966. Means ± standard deviations of the results from three different assays are shown, and statistical significance (P < 0.001) is indicated. The designation ter refers to NH₂- or COOH-terminal domains. OD_405nm, optical density at 405 nm.