The RAD-SMAD reporter consists of tandem Smad GTCT binding sites driving expression of nuclearly localized GFP. GFP expression levels from this construct are positively regulated by DBL-1 signaling.
adt-2(RNAi) reduces the expression of RAD-SMAD in an otherwise wild-type background. In the
dbl-1 mutant background, RAD-SMAD expression is reduced to a few dimly fluorescing nuclei in the posterior and this expression is not diminished further by
adt-2(RNAi). Thus,
adt-2 is a positive regulator of a DBL-1-responsive reporter.