FIGURE 3.

Colonization of the light organ competition assays of the various strains compared with the wild-type strain. Competition between wild type or waaL strains and MJM1575 (lacZ-labeled wild-type V. fischeri) is shown. The RCI is calculated as the ratio of (unlabeled strain/MJM1575) colonies from each animal plated, divided by the ratio of those strains in the original inoculum (20). Log₁₀(RCI) <0 indicates that MJM1575 is more prevalent than the unlabeled strain, and log₁₀(RCI) >0 indicates the opposite. Closed circles represent individual animals in which both strains were detected, and open circles indicate animals in which only one strain was detected; the value of log₁₀(RCI) for these points represents a limit of detection. n = 10 animals for each treatment. Treatments for which mean log₁₀(RCI) was significantly different from 0 by one sample t test are indicated by †† or ††† (p < 0.01 and p < 0.001, respectively). One-way analysis of variance and unpaired t tests were also used to compare log₁₀(RCI) between competitions, with significant differences shown in figure (**, p < 0.01; ***, p < 0.001).