FIG 9.

sypE −1 frameshift allele is not sufficient to affect colonization ability. The indicated strains were assayed in a single-strain colonization assay. Gray boxes denote alleles distinct from their wild-type background. Frameshift “fs” refers to alleles, relative to an ES114 reference, that lack rscS nucleotide A1141 or that lack sypE nucleotide G33. The wild-type MB11B1 strain contains natural frameshifts in these loci, and the ES114 nt33::ΔG allele was constructed. Addition back of the nucleotide in MB11B1 sypE is denoted (+). Hatchling squid were inoculated with 6.8 × 10² to 8.4 × 10² CFU/ml bacteria (MB11B1 background) or 4.0 × 10³ to 5.4 × 10³ CFU/ml bacteria (ES114 background), washed at 3 h and 24 h, and assayed at 48 h. Each dot represents an individual squid. The limit of detection is represented by the dashed line, and the bars represent the median for each set. Strains are MJM1100, MJM3010, MJM4323, MJM3394, MJM1130, and MJM3397. Statistical comparisons were done with the Mann-Whitney test. ns, not significant.