Characterization of nervana, a Drosophila melanogaster neuron-specific glycoprotein antigen recognized by anti-horseradish peroxidase antibodies.

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 Mr 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 Mr 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.