Goblet cell-specific expression mediated by theMUC2 mucin gene promoter in the intestine of transgenic mice

The regulation ofMUC2, a major goblet cell mucin gene, was examined by constructing transgenic mice containing bases −2864 to +17 of the human MUC25′-flanking region fused into the 5′-untranslated region of a human growth hormone (hGH) reporter gene. Four of eight transgenic lines expressed reporter. hGH message expression was highest in the distal small intestine, with only one line expressing comparable levels in the colon. This contrasts with endogenousMUC2 expression, which is expressed at its highest levels in the colon. Immunohistochemical analysis indicated that goblet cell-specific expression of reporter begins deep in the crypts, as does endogenous MUC2 gene expression. These results indicate that theMUC2 5′-flanking sequence contains elements sufficient for the appropriate expression ofMUC2 in small intestinal goblet cells. Conversely, elements located outside this region appear necessary for efficient colonic expression, implying that the two tissues utilize different regulatory elements. Thus ...