Fig. 6. Intestinal differentiation in pancreatic explants is induced by activin A, but not by activin B. Treatment of explants with activin A leads to the appearance of an intestinal structure (A) seen here on day 4 in culture (scale bar, 500 µm) and induces the intestinal markers i-Fabp and l-Fabp, detected by RT-PCR on day 7, as well as Shh, detected by semi-quantitative RT-PCR on day 7 (B). None of these effects are seen when activin B is used instead of activin A.