Fly Visual Pigments Difference in Visual Pigments of Blowfly and Dronefly Peripheral Retinula Cells

The visual pigments of peripheral retinula cells in fly eyes have been investigated by microspectrophotometry in vivo. Since flies have a pupil mechanism which may invalidate the visual pigment measurements, the technique has been applied to the pupil-less mutant chalky of the blowfly Calliphora erythrocephala. It proves that the data acquired previously from wild type blowflies with the in vivo method are indeed reliable. Blowfly peripheral retinula cells contain a blue-green absorbing rhodopsin. P495, which is photo-interconvertible with a yellow absorbing metarhodopsin M580. The transformation of rhodopsin into metarhodopsin occurs within milliseconds. Peripheral retinula cells of wild type droneflies contain a rhodopsin P460 and a metarhodopsin M550. Both blowfly and dronefly belong to the suborder of Brachycera and both have a strongly bathochromic shifted metarhodopsin; yet, the characteristics of their visual pigments appear to be quite distinct.