title: Immunolocalization of immune cells and cell cycle proteins in the bulbus arteriosus of Atlantic salmon (Salmo salar L.).
abstract: The bulbus arteriosus is the most anterior chamber of the teleost heart. The present study aimed to establish the presence, and to provide semi-quantitative information on the abundance, of several immune and cell-cycle proteins in the bulbus arteriosus of healthy Atlantic salmon (Salmo salar L.). Using immunohistochemistry, lymphocyte-like cells were identified in the bulbus arteriosus using antibodies to CD3ε and MHC class IIβ. Few PCNA positive cells were identified in post-smolt fish as compared to moderate levels of staining in fresh water fry. Interestingly no staining was evident in adult fish (1-3 kg), thus there was a loss of cells expressing cell-cycle regulatory proteins with ontogeny/progressive life-history stages. Eosinophilic granulocytes (EGCs) were identified in the bulbus arteriosus using TNFα and HIF1α antibodies. Anti-caspase 3 immune-reaction identified a strong endothelial cytoplasmic staining in the bulbus arteriosus. Taken together, the immunolocalization of immune-related molecules (CD3, MHC class II and TNFα), cell-cycle regulatory proteins (PCNA and HIF1α) and apoptosis markers (TUNEL, caspase 3) suggest that the bulbus arteriosus may have an immune component within its functional repertoire.
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, Bodø, Norway. Electronic address: drnavidyusuf@yahoo.com.
authors.forename: Muhammad Naveed
authors.initials: MN
authors.lastname: Yousaf
authors.affiliation: Department of Basic Sciences and Aquatic Medicine, School of Veterinary Medicine, NMBU, Oslo, Norway.
authors.forename: Erling Olaf
authors.initials: EO
authors.lastname: Koppang
authors.affiliation: Scottish Fish Immunology Research Centre, University of Aberdeen, Aberdeen, UK.
authors.forename: Jun
authors.initials: J
authors.lastname: Zou
authors.affiliation: Scottish Fish Immunology Research Centre, University of Aberdeen, Aberdeen, UK.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Secombes
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, Bodø, Norway.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Powell
mesh_terms: D000818:Animals; D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D006321:Heart / Q000502:physiology; D007150:Immunohistochemistry / Q000662:veterinary; D009206:Myocardium / Q000166:cytology* / Q000276:immunology; D020317:Salmo salar / Q000276:immunology*
chemical_list: D018797:Cell Cycle Proteins; D029941:Fish Proteins
keywords: Atlantic salmon; Bulbus arteriosus; CD3; Caspase; HIF1α; Immunohistochemistry; MHC II; TNFα