Hsp70 promoter sequences drive expression of the exd coding region, poly(A) tail is provided by Ubx.
wild-type
Ubiquitous expression in wild type flies during development does not appear to have any morphological consequences.
exdhs.PR3 rescues exd1
Single heat shock at the onset of gastrulation rescues exd1 embryos A1 to A2 transformation to almost normal morphology.