Ultrastructural localization of H human-blood-group immunoreactivity rat cochlear hair cells.

Human blood-group antigens are transiently expressed in developing cochlear hair cells. This temporal antigen expression seems to correspond to the main events of inner ear differentiation (e.g. hair cell development, synaptogenesis, ciliogenesis). In the present report, the cochlear expression of H human blood group antigen has been analyzed with the aid of the electron microscope. Ultrastructurally, cochleas stained with anti-H antibody exhibited an intense immunoreactivity on the apical hair cell membrane and on stereocilia. Cell surface glycoconjugates may serve a large number of functions and could be important during cell development. The temporal expression of H blood-group antigen in developing cochlear hair cells could be related to stereocilia differentiation.