Altering the number of pMad motifs affects visceral mesoderm activity.

<p>Double <i>in situ</i> hybridizations against (A–C) the <i>lacZ</i> reporter gene driven by the pMad homotypic synthetic CRMs (red) and (A′–C′) the endogenous <i>dpp</i> gene (green). (A″–C″) Expression patterns in the foregut (white arrowhead); hindgut (arrow); parasegment 3 (PS3) (light blue arrowhead) and 7 (PS7) (dark blue arrowhead) of the midgut visceral mesoderm (VM). Dashed box is enlarged in the inset (white box). Embryos are dorsally oriented, with anterior to the left, stage 13/14. (A′″–C′″) Schematic representations of the CRM composition, where purple triangles depict the number and orientation of pMad sites with indicated spacing (bp) between adjacent sites.