FIG. 1.

Histological analysis of trinitrobenzene sulfonic acid (TNBS) -induced enterocolitis in zebrafish larvae reared in conventionally reared (CV) conditions or a germ-free (GF) environment and harvested at 8 days post fertilization (dpf ), and ex-germ-free (XGF) zebrafish conventionalized at 8 dpf and harvested 2 days later. (A) Representative hematoxylin-eosin-stained sagittal sections of the intestine of zebrafish from different groups. Arrows indicate goblet cells, and arrowheads demonstrate projections and clefts. a, anus; ib, intestinal bulb; Ph, pharynx; s, somite; sb, swim bladder. (B) Total enterocolitis score. A total of 30 folds (10 per intestinal segment) were evaluated per intestine, and six intestines were evaluated for each experimental group from three independent experiments. The scores were quantified by a blinded scorer. All error bars are represented as means±SEM. *p<0.05, **p<0.01, and ***p<0.001. Color images available online at www.liebertpub.com/zeb