Expression of SV-40 T antigen in the small intestinal epithelium of transgenic mice results in proliferative changes in the crypt and reentry of villus-associated enterocytes into the cell cycle but has no apparent effect oncellular differentiation programs and does not cause neoplastic transformation

The relationshipbetween cell division and cell differentiation was studied in transgenic mice expressing SV-40 T antigen (Tag) in the epithelial cells of the small intestinal crypts and in the already committed, differentiating enterocytes that have begun migrating up the villus. The results showed that Tag productionwas associated with an increase in cell proliferation, but it had no effect on cellular commitment to differentiate into enterocytic, enteroendocrine or Paneth cells.