(A) We generated a DPAGT1 model that drives RNAi against DPAGT1 in the fly eye (middle). This causes a small, rough eye phenotype. In addition to the DPAGT1 model, we also used an ER stress fly model that overexpresses the misfolded protein Rh1G69D in the eye (right). (B) RNAi against the mannosyltransferase Dpm1 strongly rescues the DPAGT1 model. The three images are representative from the same experimental cross and RNAi line (BDSC 51396) or control RNAi background (attP2, BDSC 36303). (C) Quantification of Dpm1 rescue of the DPAGT1 model. For reference, a representative DPAGT1 genetically-matched background strain crossed to the control RNAi line is included to indicate the wild type eye size (Wild type).**** p<0.0001 (Student’s t test). (D) Dpm1 RNAi rescues the ER stress model. Eye images are representative from the same experimental cross and RNAi line (BDSC 50713) or control RNAi background (attP40, BDSC 36304). (E) Quantification of Dpm1 rescue of the ER stress model. For reference, a representative ER stress genetically-matched background strain crossed to the control RNAi line is included to indicate the wild type eye size (Wild type). **** p<0.0001 (Student’s t test).