(A) Fold changes of respective transcripts (thickvein (tkv), schnurri (shn), Mothers against dpp (Mad) and GATAe) in Sox21a mutant EBs compared to wild type EBs. (B-C) The level of Dpp signaling activity was detected with the Dad-GFPnls reporter (in green) in wild-type flies (B) or flies over-expressing Sox21a in progenitors for 36 hours (C). Some differentiating EBs are indicated with yellow arrows (C). Arm (in red, membrane), Pros (in red, nuclei) and DAPI staining are shown. (D-E) Sox21a mutant clones (positively labeled by GFP, D) and Sox21a mutant clones expressing the Dpp pathway transcription factor Schnurri (E) are analyzed 7 days after clone induction. Note that the blockage in differentiation of Sox21a mutant clone cells was not rescued by the shn expression.