Evidence for an inactive plasma membrane-associated precursor of active cytoplasmic ornithine decarboxylase in developing embryos of Muscadomestica

During embryonic development of Musca domestica inactive ornithine decarboxylase protein appears in the embryos at 6 h postoviposition, increases in concentration and reaches a maximum level at 9 h postoviposition. The inactive enzyme is associated with the plasma membrane and appears to be the precursor for active ornithine decarboxylase, which is associated with the cytosolic fraction just prior to hatching. Both ornithine decarboxylase protein and enzymatic activity disappear during the early larval stage of this insect.