Fig. 2

Enhanced expression of codon optimized MiniSOG in Drosophila which generates robust EM contrast after photo-oxidation reaction. a. Western blot of cell extracts prepared from cells transfected with equal amounts of original human MiniSOG (hMiniSOG, left lane)[1] and Drosophila codon optimized MiniSOG (DmMiniSOG or DMS, right lane) probed with anti-HA antibodies (upper panel) and anti-actin antibodies (lower panel) as a loading control. b. Bar chart showing the normalized expression levels (HA/actin ratio) for hMiniSOG and DmMiniSOG from three independent experiments. DmMiniSOG shows an 83 % increase in expression level compared to hMiniSOG. c. inducible expression of DMS fusion proteins by metallothionein promoter. Cells transfected with pMK33B-mCherry DMS-His2Av construct were observed under confocal microscopy. Robust expression of the DMS-His2Av fusion was only observed after 0.5 M copper sulphate was added to the culture (lower right panel, mCherry chanel) whereas no expression in cells without cupper induction (upper right panel). d. High-contrast dark precipitate observed in cells transfected with pUbi-DMS after photo-oxidation (lower right panel, dark arrows) but not in mock transfected cells (upper panels), under a light microscope