Figure 1.—

Schematic of the heritable and inducible RNAi system. Two transgenic fly stocks, GAL4-driver and UAS-D-DDB1(650)-dsRNA, are used in this system. The GAL4-driver fly used in this experiment has a transgene-conjugating yeast transcriptional factor GAL4. In this report, we used Act5C-GAL4 and Act25-GAL4 as a GAL4 driver to induce D-DDB1 gene silencing in all cells of the fly, ey-GAL4 and GMR-GAL4 to induce D-DDB1 gene silencing in the eye imaginal disc, and CgGAL4 to induce D-DDB1 gene silencing in the fat body. The UAS-D-DDB1(650)-dsRNA fly has a transgene containing the inverted repeat of the 650-bp dsRNA fragment (101–750 bp of the ORF) of D-DDB1 separated by the D-DDB1 gene (1–100 bp of the ORF) sequence ligated to the UAS promoter, a target of GAL4. In the F₁ progeny of these flies, the 650-bp dsRNA of the target gene is expressed to induce the gene silencing.