Fig. 9. Activation of Scd1 and Dpp4 enhancers by Gata6 and Nkx2.1. Region A in Scd1 and Dpp4, and region B in Scd1 were all cloned into the pGL3promoter plasmid. These regions contain both Gata6 (stars) and Nkx2.1 (circles) DNA-binding sites. (A,B) In NIH-3T3 cells, expression of either Gata6 or Nkx2.1 transactivated region A in Scd1 and Dpp4 in a dose-dependent manner. However, co-expression of Gata6 and Nkx2.1 did not synergistically activate either of these enhancer regions. (C) Gata6 and Nkx2.1 synergistically activated Scd1 region B, even though this region lacks Gata6 DNA-binding sites. Data represent the average of three assays ±s.e.m.