Intermediate filament expression in human fetal olfactory epithelium

Antibodies to intermediate filaments and to desmoplakin were used to investigate the histogenetic origin of the olfactory neuroepithelium. Intermediate-filaments are tissue-specific molecular cytoskeletal markers; desmoplakin is the major desmosomal protein. The olfactory epithelia of eight human fetuses, aged 7 to 10 weeks (fertilization age) were immunofluorescently labeled with antibodies to the five classes of intermediate-filament proteins and to desmoplakin. Positive immunoreactivity to keratin and to desmoplakin was observed; both results indicate the epithelial nature of this tissue. The absence of neurofilaments and glial-fibrillary acidic protein in the tissue containing sensory neurons and gliallike supporting cells is a unique feature, and may be related to the fact that olfactory neuroepithelium, like other epithelia, undergoes continuous turnover.