P{EP}EP3330 is inserted at 64 bp upstream of the first exon specific to rols isoform 6 (3rd exon of rols), into the putative promoter for this isoform.
Initial determination, budding and elongation of Malpighian tubules during stage 13-14 is normal in rolsEP3330 homozygous embryos. However rearrangement of tubule cells to produce elongated, 2 cell wide tubules is delayed (from stage 15 to stage 16-17) and partially disrupted. Tubule migration is defective from stage 15. The anterior tubules appear to follow a random path through the body cavity, sometimes doubling back on themselves and failing to form the usual kink at A2/A3.