FIG 2.

Strain frequency of crypts in cocolonized light organs. (A) Scoring system for individual squid from a cocolonization assay. Crypts of colonized animal are scored as CFP/YFP/mixed/empty. I, II, and III refer to crypt numbers, and L and R indicate left and right sides of light organ, respectively. CFU-based competitive index (CFU CI) values were determined by calculating the test CFU/control CFU ratio using homogenized animals. (B) CFU-based competitive index values determined for individual squid cocolonized with the CFP-labeled wild-type strain (control) and the indicated YFP-labeled test strain. Each triangle represents an individual animal. Data sets correspond to trial 1 of the respective test strain (Table 1). Circles and error bars represent means and 95% confidence intervals. For each trial, gray bars represent the 95% confidence interval, and black and white bars represent the corresponding lower and upper confidence bounds, respectively. (C and D) Strain frequencies of crypts in animals determined as described for panel B. The test strains were the WT strain (C) and the Δlux mutant (D). Blue, green, and red represent the control strain (CFP), the test strain (YFP), and both strain types, respectively. Grayscale bars indicate animal subgroups defined by 95% confidence intervals as described for panel B. Crypt competitive indices (crypt CI) were calculated as numbers of crypts containing the test strain/numbers of crypts containing the control strain.