The RMCE cassette in TI{T-GEM.0}EhGal4 has been replaced with sequence encoding Eh third intron sequence (from 3' to the original insertion site) and the coding sequence of Eh exon 4, following by T2A-GAL4. This results in the reconstitution of full-length Eh coding sequence, and the presence of the T2A sequence allows separate translation of the GAL4 driver under the control of endogenous Eh regulatory sequences.
Reporter expression is observed in the EH neurosecretory neurons in L1, L2 and L3 and in additional neurons in L3. Labeling is consistantly observed in all larval stages in the anterior and posterior spiracles and in cells associated with the mouthparts. In addition to spiracle and mouthpart labeling, expression at L1/L2 includes epithelial cells of the dorsal tracheal trunks, numerous superficial cells along the ventral and lateral body wall, and cells in segments T1 to T3 surrounding Keilin’s organs. Cells on the segmental branches of the dorsal tracheal trunks are also weakly labeled. In pharate adults, expression is observed in presumptive head and thoracic air sacs.