title: Cell proliferation and apoptosis in the olfactory epithelium of the shark Scyliorhinus canicula.
abstract: To date, no study has been published on cell renewal in the olfactory epithelium of Chondrichthyes. Our work aimed at detecting proliferating cells (by Proliferating Cell Nuclear Antigen - PCNA immunohistochemistry) and apoptotic cells (by terminal uridine deoxynucleotidyl transferase nick end labeling method) in the olfactory epithelium of the shark Scyliorhinus canicula. PCNA immunoreactivity and mitotic figures were localized almost exclusively at the basal and apical thirds of the epithelial thickness. Double immunofluorescence for PCNA and OMP (a marker of mature olfactory neurons) showed that PCNA immunoreactivity is lacking in mature olfactory neurons, with the exception of crypt neurons. Crypt neurons, a cell type peculiar to fish, often showed PCNA immunoreactivity in the nucleus and may be involved in repair processes. The role of PCNA in mature crypt neurons requires further investigation to be clarified. Apoptosis was observed in sensory neurons and in basal cells. Our data highlight the presence of cell proliferation at different levels within the epithelium and the occurrence of apoptosis in both mature and proliferating cells.
authors.affiliation: Department of Biology, University of Genoa, Viale Benedetto XV, Genoa, Italy. sara.ferrando@unige.it
authors.forename: Sara
authors.initials: S
authors.lastname: Ferrando
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gallus
authors.forename: Chiara
authors.initials: C
authors.lastname: Gambardella
authors.forename: Laura
authors.initials: L
authors.lastname: Ghigliotti
authors.forename: Silvia
authors.initials: S
authors.lastname: Ravera
authors.forename: Mauro
authors.initials: M
authors.lastname: Vallarino
authors.forename: Marino
authors.initials: M
authors.lastname: Vacchi
authors.forename: Grazia
authors.initials: G
authors.lastname: Tagliafierro
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D049109:Cell Proliferation; D004284:Dogfish / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D020287:In Situ Nick-End Labeling / Q000379:methods; D008297:Male; D023421:Models, Animal; D009831:Olfactory Mucosa / Q000166:cytology* / Q000254:growth & development; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000378:metabolism