Characterization of Nervana, a Drosophila melanogaster Neuron-Specific Glycoprotein Antigen Recognized by Anti-Horseradish Peroxidase Antibodies

Abstract: Antibodies to the plant glycoprotein horseradish peroxidase (HRP) are used extensively to identify neurons in Drosophila and other insects. We are interested in characterizing the gene product(s) recognized by anti-HRP antibodies because it may be important for nervous system function and/or development. Here we identify and purify from adult Drosophila heads an anti-HRP-reactive M_r 42K glycoprotein that is likely to be the major contributor to neuronal specific anti-HRP staining. Several different monoclonal antibodies to the purified 42K glycoprotein recognize up to three proteins with distinct mobilities between M_r 38K and 42K that vary as a function of developmental age. We have collectively named these components Nervana (nerve antigen), because the monoclonal antibodies also specifically stain cultured neurons and embryonic nervous system with a pattern indistinguishable from anti-HRP staining. Western blots indicate the presence of immunologically similar proteins in a wide variety of insect species and in nac (neurally altered carbohydrate) mutant Drosophila flies that lack anti-HRP staining in adult nervous system. It should now be possible to undertake a full biochemical and functional characterization of Nervana in Drosophila .