Genetic interaction between Myc and components of the insulin and TOR pathways. (A) Scanning electron micrographs of adult eyes from ey- dm+/Y (a-d), ey- dmP0/Y (a'-d') and ey- dm4/Y (a"-d") animals expressing the following transgenes: (a) control yw, (b) UAS-Dp110, (c) UAS-PTEN, and (d) UAS-RhebAV4. All pictures are shown at the same magnification; posterior is to the left. Insets show higher-magnification views of the ommatidia. Numbers at the top right indicate cell size variation as compared to control (100) for each genotype also reported in panel B and C and Table 1. Histograms are representing the means of the (B) ommatidial size or (C) number of the indicated insulin and TOR components in different dm genetic backgrounds. The standard deviations were calculated based on the total number of animals, as indicated in Table 1. Note that the reduction of dm levels resulted in a small but significant decrease in ommatidial size in ey-dmP0/Y flies as compared to control ey-dm+/Y (Panel B and C, and Table S2 in Additional file 5; P < 0.001, calculated using Student t test). This difference was more pronounced in the eye of dm4/Y flies where the size of the ommatidia was reduced by 24% as compared to ey-dm+/Y flies. In addition, while the total number of the ommatidia was similar for ey-dmP0/Y flies and control ey-dm+/Y animals, flies with a null genetic background for dm (ey-dm4/Y) showed an 11% of reduction in the total number of the ommatidia as compared to ey-dm+/Y eyes . TOR: target of rapamycin.