FIG 8.

Drosophila mutants for Tep2 and Tep4 exhibit elevated levels of nitric oxide after infection with Photorhabdus. Nitrite levels in tep loss-of-function mutants and background controls (n = 5) injected with E. coli (Ec), P. luminescens (Pl), P. asymbiotica (Pa), or 1× PBS (negative control) were estimated. The concentration of nitrite (micromolar) is normalized to the protein content (micrograms per milliliter) and represented as a ratio of total nitrite levels to total protein levels in tep2 mutants (A and B) and tep4 mutants (C and D) with the corresponding background control strains (w¹¹¹⁸ and yw, respectively) at 6 and 18 h postinjection. The means from three independent experiments are shown, and error bars represent standard deviations. Significant differences are shown with asterisks (*, P < 0.05; **, P < 0.01; ***, P < 0.001).