FIG. 4.

Colonic tissues taken from wild-type (wt) and RAG1 KO mice express IFN-γ mRNA during C. rodentium infection, but only wild-type mice showed increased expression during infection. RT-PCR for IFN-γ shows expression significantly increases in the tissues of wild-type mice, from undetectable levels in uninfected mice to a progressive elevation in expression seen on days 6, 10, and 18 p.i. In contrast, as the infection progressed, IFN-γ mRNA expression progressively decreased in the colons of RAG1 KO mice at each of days 6, 10, and 18 p.i. GAPDH was used as the housekeeping gene control.