G-protein(S), G alpha q/G alpha 11, in the olfactory neuroepithelium of the channel catfish (Ictalurus punctatus) is altered by the herbicide, dichlobenil.

The immunohistochemical localization of G alpha q/G alpha 11 was studied in the olfactory neuroepithelium of the channel catfish. Antigenicity in the rosette was found at the apical surfaces of cells, within the apical neck regions of some cells, and within the area of the basal nerve tracts. Specific labeling was eliminated by preincubation of the G alpha q/G alpha 11 antibodies with the cognate peptide. Catfish, exposed to a 20 ppm dose of the herbicide, dichlobenil, displayed a reduction in G alpha q/G alpha 11 antigenicity. Proteins were extracted from olfactory tissues and solubilized. Using SDS-PAGE and Western blotting, bands corresponding in apparent molecular weight to a 38 kD protein were found. These data demonstrate that the herbicide may be a potent nasal olfactory toxicant in aquatic situations.