copia insertion 243bp 5' to the distal transcription start site.
The relative level of transcripts in the AdhSL variant is 2-10 fold lower than in AdhS at all developmental stages tested except embryos where the levels are the same. The most dramatic reductions in Adh transcript levels occur in stages and tissues where copia is abundantly expressed, namely in larvae, >2 day old adults, and in fat body. AdhRI-42 transcript levels are elevated in adults in a su(wa) or a su(f) genetic background.
Precise deletion of the copia insertion by in vitro mutagenesis demonstrates the insertion causes the very low Adh protein levels. Excision of the copia insertion causes a three fold increase in the level of Adh protein.