Figure 4

RNA chromogenic in-situ hybridization dual probe for sucrase-isomaltase (brown) and Hes1 (red). Transcripts were quantified in the ileum of non-infected pigs (NC), non-vaccinated Lawsonia intracellularis inoculated pigs (PC), and vaccinated Lawsonia intracellularis inoculated pigs (VAC) at days post-inoculation 21. Representative images of dual stain in A NC, B PC, and C VAC pigs. Sucrase-isomaltase transcript was found throughout the intestinal epithelium, particularly concentrated in the mid-villus region and villus tips. Near complete abolition of this transcript was observed in affected crypts in pigs challenged with L. intracellularis. The abundance of transcription factor Hes1 was also evaluated by RNA in-situ hybridization. D Example of Hes1 staining in the crypts. Hes1 transcript appeared sporadically throughout the crypt-villus axis in all treatment groups. However, due to the overwhelming sucrase-isomaltase staining, this transcript was unable to be quantified. E Quantification of sucrase isomaltase stain in the crypt, mid-villus, and villus tip.