Tissue localization of esterase-5 in Drosophila pseudoobscura.

Disc gel electrophoresis of dissected adults of Drosophila pseudoobscura showed that most of the esterase-5 activity was in the head (36%) and thorax (51%), with little activity in the abdomen (13%). No activity was found in digestive tissues, reproductive tissues, or nervous tissues. Most of the est-5 activity (61%) was found to be associated with hemolymph. However, the eyes contained 39% of the total est-5 activity. These results were supported by spectrophotometric assays of esterase activity in crude extracts of eyes and whole flies without eyes which showed that 27% of the total est-5 activity was in the eyes.