title: Molecular cloning and characterization of adult Sparus aurata hemoglobin genes.
abstract: Among Teleosts, Sparus aurata occupies a prominent place in the gastronomic and economic fields of the Mediterranean basin and other geographic districts. The knowledge of its molecular structures and functional features, such as hemoglobin, may be helpful to understand the adaptive biochemical mechanisms that allow this fish to live under extreme conditions, including fish farming. In Sparus aurata red blood cells two different alpha and one beta hemoglobin genes have been identified. The alpha1 gene codifies a putative protein of 144 amino acids, the alpha2 gene produces a protein of 143 amino acids, and the beta gene encodes a chain of 148 amino acids. Comparative analysis of various hemoglobins indicates that allosteric regulation can be modified by the substitution of one or a few key residues. The comparison of the percentage sequence differences for alpha and beta chains in fishes indicates that evolutionary relationships between different species may be helpful to understand the mechanisms of their differentiation from other vertebrates. Hemoglobin alpha and beta chains of about 50 teleostean temperate and Antarctic fishes were analyzed to build phylogenetic trees using different algorithms: the neighbor-joining method, the maximum likelihood approach, and the Bayesian inference computation. Sparus aurata alpha chains are positioned in a paraphyletic cluster, which includes the same subunit of Chrysophrys auratus and Seriola quinqueradiata, whereas the beta chain is on an homophyletic branch with that of Chrysophrys auratus. Therefore, the phylogenetic approach suggests that both Sparus aurata hemoglobin alpha genes are paralogues and may have derived from a duplication event.
authors.affiliation: Department of Biochemical, Physiological and Nutritional Sciences, School of Medicine, University of Messina, Messina, Italy. scampo@unime.it
authors.forename: Salvatore
authors.initials: S
authors.lastname: Campo
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Nastasi
authors.forename: Donatella
authors.initials: D
authors.lastname: Fedeli
authors.forename: Angela
authors.initials: A
authors.lastname: D'Ascola
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Campo
authors.forename: Angela
authors.initials: A
authors.lastname: Avenoso
authors.forename: Alida
authors.initials: A
authors.lastname: Ferlazzo
authors.forename: Alberto
authors.initials: A
authors.lastname: Calatroni
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Falcioni
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D006454:Hemoglobins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D021541:Sea Bream / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D029941:Fish Proteins; D006454:Hemoglobins