A cDNA fragment corresponding to sd with an internal deletion, removing amino acids 220-281, is expressed under the control of UASt regulatory sequences. The deletion removes the sd vestigial interacting domain.
sdΔ220-281.UAS/Scer\GAL4vg.boundary fails to rescue sd58d
sdΔ220-281.UAS/Scer\GAL4vg.boundary fails to rescue sdETX4