Fig. 2

Extremes of LTA4H Expression Drive Hypersusceptibility in Zebrafish (A) Median number of macrophages recruited to the hindbrain ventricle of wild-type and LTA4H-high siblings 4 hr after injection of 150-200 M. marinum into this space at 30 hpf. p = 0.01 (Student′s unpaired t test). Representative of two independent experiments. (B) TNF mRNA levels (mean ± SEM of three independent experiments) for control and LTA4H-high siblings 1 dpi with 150-200 M. marinum. p = 0.02 by Student′s unpaired t test. (C) Fluorescence images of representative wild-type, LTA4H-low and LTA4H-high larvae 3 dpi with 90-100 M. marinum. (D) Bacterial burden of all larvae from (C) by fluorescence pixel counts (FPC). ^**p < 0.01; ^***p < 0.001. (one-way ANOVA with Tukey′s post hoc test; all other comparisons not significant). Representative of > 7 independent experiments measuring differences in bacterial burden of the three genotypes. (E) Mean (±SEM) number of bacteria per infected macrophage in 11 wild-type larvae, 8 LTA4H-low larvae and 13 LTA4H-high larvae, 40 hpi with 150-200 erp mutant M. marinum. ^***p < 0.001 (one way ANOVA with Dunnett′s post hoc test). Representative of two independent experiments. (F) Fluorescence images showing discrete bacterial clumps indicative of macrophage residence in wild-type versus corded extracellular bacteria in their LTA4H-low and LTA4H-high siblings at 3 dpi with 150-200 M. marinum. (G) Percentage of animals in (F) with cording among wild-type, LTA4H-low and LTA4H-high siblings 4 dpi after infection with 90-100 M. marinum. ^*p < 0.05; ^***p < 0.001 (Fisher′s exact test comparing LTA4H-low and LTA4H-high to wild-type). (H) Quantitation of neutral red positive cells 4 dpi after infection with approximately 100 M. marinum in sibling controls and LTA4H-high animals and (I) sibling controls and LTA4H-low animals. See also Figure S2 and Movie S1, Movie S2, and Movie S3.