Preparation of monoclonal antibody against celangulin V and immunolocalization of receptor in the oriental armyworm, Mythimna separata walker (Lepidoptera: Noctuidae).

The botanical insecticide celangulin V (CA-V) is an insect digestive poison acting on midgut tissue of the target insect larvae. With the aim of localizing the receptor enacted by CA-V, monoclonal antibodies (MAbs) specific to the compound were developed. A hapten was synthesized by introducing a succinoyl into the CA-V structure and conjugated with three carrier proteins. From mice immunized with one conjugate, three MAbs were obtained with a potential capacity of detecting protein-bound residue forms of CA-V in the biological tissues. The oriental armyworm larvae ingested CA-V were examined by the technique of immuno-electron-microscopy (IEM) using the anti-CA-V MAb as the primary antibody and goat anti-mouse/IgG labeled with colloidal gold as the secondary antibody. Electron micrographs of the armyworm midgut tissues showed that the CA-V was associated with the midgut epithelia of the insects. These results demonstrated the existence of a receptor enacted by CA-V on the midgut cells of the oriental armyworm larvae.