Fig. 1.

Reduction of dELL levels on polytene chromosomes after RNAi. Flies carrying a Gal4-responsive dsRNA construct were crossed to flies expressing one copy of Gal4 driven by the Actin5C promoter. (Upper) Salivary gland polytene chromosomes from control larvae (RNAi OFF) carrying the second chromosome balancer CyO were seen to express dELL at numerous interband sites of polytene chromosomes. (Lower) In contrast, RNAi larvae (RNAi ON), expressing Gal4, have greatly reduced levels of dELL throughout the salivary gland nucleus. HP1 levels on control and dELL knockdown larvae were comparable.