Fig. 2

Position effects and DCV-1A mediated suppression of silencing by the white GMR-hairpin transgene in the presence or absence of gypsy insulators. Far left, (1) eye color phenotype of GMR-GAL4; UAS-GFP flies (VK1). (2) Eye color of flies bearing GMR-whiteIR; GMR-GAL4; UAS-GFP transgenes (VK1). (3–6) Suppression of white silencing by DCV-1A expressed from the VK1 landing site with upstream, downstream, flanking (both), or no gypsy insulators. (7–10) Suppression from the attP40 landing site with upstream, downstream, flanking, or no gypsy insulators. (11) Eye color phenotype of GMR-whiteIR; GMR-GAL4; UAS-GFP (attP18) flies. (12–15) Suppression from attP18 landing site with upstream, downstream, flanking, or no gypsy insulators. Eye pigment levels were measured in three separate experiments using age-matched 4-day-old adults, and are expressed as a percentage relative to the pigment levels measured in the GMR-GAL4; UAS-GFP (VK1) controls. Error bars represent standard error. Significance was calculated by Student’s t-test.