MONOCLONAL-ANTIBODIES SPECIFIC FOR ENDOPLASMIC MEMBRANES OF MAMMALIANCOCHLEAR OUTER HAIR-CELLS

Monoclonal antibodies were raised in vitro against an antigen associat ed with the lateral cisternal membranes of outer hair cells. Two of th e antibodies were class IgM and one of these retained its specific rea ctivity in tissue fixed with aldehydes and embedded in the resin LR Wh ite. Immunogold labelling for electron microscopy showed that the anti gen was closely associated with the membranes rather than the cytoplas mic or lumenal regions of the cisternae. The third antibody was an IgG . All three weakly labelled a protein band with an apparent molecular weight of about 60 kD on a Western blot. The antibodies did not cross- react with any other cell in the organ of Corti, including the inner h air cells. Furthermore, they showed no cross-reactivity with skeletal muscle, kidney, gut, brain, skin, blood or retina from the guinea pig. The results suggest that the lateral cisternae in outer hair cells ma y be functionally different from those of inner hair cells. The antibo dies may provide useful markers for outer hair cells in studies of hai r cell regeneration.