title: Spheniscins, avian beta-defensins in preserved stomach contents of the king penguin, Aptenodytes patagonicus.
abstract: During the last part of egg incubation in king penguins, the male can preserve undigested food in the stomach for several weeks. This ensures survival of the newly hatched chick, in cases where the return of the foraging female from the sea is delayed. In accordance with the characterization of stress-induced bacteria, we demonstrate the occurrence of strong antimicrobial activities in preserved stomach contents. We isolated and fully characterized two isoforms of a novel 38-residue antimicrobial peptide (AMP), spheniscin, belonging to the beta-defensin subfamily. Spheniscin concentration was found to strongly increase during the period of food storage. Using a synthetic version of one of two spheniscin isoforms, we established that this peptide has a broad activity spectrum, affecting the growth of both pathogenic bacteria and fungi. Altogether, our data suggest that spheniscins and other, not yet identified, antimicrobial substances may play a role in the long term preservation of stored food in the stomach of king penguins.
authors.affiliation: Centre National de la Recherche Scientifique, Centre d'Ecologie et Physiologie Energétiques, 23 rue Becquerel, F67087 Strasbourg Cedex 2, France. ceceile.thouzeau@c-strasbourg.fr
authors.forename: Cécile
authors.initials: C
authors.lastname: Thouzeau
authors.forename: Yvon
authors.initials: Y
authors.lastname: Le Maho
authors.forename: Guillaume
authors.initials: G
authors.lastname: Froget
authors.forename: Laurence
authors.initials: L
authors.lastname: Sabatier
authors.forename: Céline
authors.initials: C
authors.lastname: Le Bohec
authors.forename: Jules A
authors.initials: JA
authors.lastname: Hoffmann
authors.forename: Philippe
authors.initials: P
authors.lastname: Bulet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000302:isolation & purification; D001419:Bacteria / Q000254:growth & development; D001717:Birds / Q000502:physiology*; D005247:Feeding Behavior; D005658:Fungi / Q000254:growth & development; D005766:Gastrointestinal Contents / Q000737:chemistry*; D008297:Male; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000302:isolation & purification; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D023083:beta-Defensins / Q000032:analysis*
chemical_list: D023181:Antimicrobial Cationic Peptides; D020033:Protein Isoforms; D023083:beta-Defensins