The Developmental Profile of Ornithine Decarboxylase in Drosophila Melanogaster

Abstract

A convenient assay for ornithine decarboxylase (ODC) in Drosophila melanogaster has been developed, and is based upon the measurement of 14c-radioactivity in the form of l4co2 cleaved from 14 C-ornithine through the action of ODC in the Drosophila supernatant. Using this assay to measure ODC activity in different stages of larval development showed that the activation of ODC may be biphasic with dramatic peaks occurring at 35 hours and 58 hours of larval development. This is consistent with other studies made on ODC activity in other systems. Furthermore, evidence is given showing that ODC may be repressed nutritionally when yeast is provided to the larvae for added nourishment. Some explanation of this phenomenon is provided.