3‐H‐YDROXYRETINAL AS A CHROMOPHORE OF Drosophila melanogaster VISUAL PIGMENT ANALYZED BY HIGH‐PRESSURE LIQUID CHROMATOGRAPHY

Abstract— The chromophore of the visual pigment of the fruit fly Drosophila melanogaster was studied by high‐pressure liquid chromatography (HPLC). Oxime derivatives of the chromophore were successfully analyzed with a more polar solvent than has been used for retinaloximes. A preceding monochromatic irradiation resulted in reversible interchanges in the amount among geometric isomers of the oximes that reflected the photointerconversion of rhodopsin and metarhodopsin of the peripheral photoreceptors (Rl‐R6). Authentic all‐trans‐3‐h‐ydroxyretinal was used to identify the chromophore from metarhodopsin. Results demonstrated that the chromophore of the visual pigment in Drosophila is 3‐h‐ydroxyretinal as was proposed in larger flies.