Fig. 6. Progression through endocytosis promotes EGFR signaling. (A,B) An Hrs^D28/Df(2L)Exel6277 Drosophila eye disc stained with anti-Elav (A, green in B) and anti-Sens (magenta in B). The arrow in B indicates a group of ommatidia containing only R8 photoreceptors. (C,D) aos-lacZ expression in wild-type (C) and Hrs^D28/Df(2L)Exel6277 (D) wing discs stained in parallel with X-Gal. R1-7 differentiation and aos expression are reduced in Hrs mutants. (E) Semi-quantitative RT-PCR for Actin, mop, Tsg101 and Vps28 mRNA in D2F cells treated with mop, Tsg101 or Vps28 dsRNA, demonstrating efficient knockdown in each case. (F) Western blot with antibodies to Tubulin and diphospho-MAPK of lysates from D2F cells treated with lacZ, mop, Tsg101 or Vps28 dsRNA and incubated with Spi for 0 or 30 minutes. Depletion of either Mop or the ESCRT-I complex components reduced MAPK phosphorylation.