title: Peptidomic analysis of skin secretions provides insight into the taxonomic status of the African clawed frogs Xenopus victorianus and Xenopus laevis sudanensis (Pipidae).
abstract: Peptidomic analysis was used to compare the distribution of host-defense peptides in norepinephrine-stimulated skin secretions from Xenopus victorianusAhl, 1924 (also described as the subspecies X. laevis victorianus) and Xenopus laevis sudanensisPerret, 1966 with the previously determined distributions in Xenopus laevis (Daudin, 1802) and Xenopus petersii Bocage, 1895. Peptides belonging to the magainin, peptide glycine-leucine-amide (PGLa), and caerulein precursor fragment (CPF) families were purified by reversed-phase HPLC and characterized by electrospray mass spectrometry. Magainin-P2, PGLa-P1, CPF-P1, CPF-P2, and CPF-P3 previously isolated from X. petersii and structurally different from orthologous peptides from X. laevis, were identified in X. victorianus and X. laevis sudanensis skin secretions whereas the corresponding X. laevis peptides were absent. Magainin-1, identical in X. petersii and X. laevis, was also identified in the secretions. Xenopsin-precursor fragment (XPF) peptides, absent from X. petersii but present in X. laevis skin secretions, were not identified in the X. victorianus and X. laevis sudanensis secretions. The data indicate that X. victorianus and X. laevis sudanensis are more closely related to X. petersii than to X. laevis and support separate species status. The study illustrates the value of analysis of host-defense peptides in the evaluation of taxonomic and phylogenetic relationships between closely related frog species.
authors.affiliation: Rare Species Conservatory Foundation, St. Louis, MO 63110, USA.
authors.forename: Jay D
authors.initials: JD
authors.lastname: King
authors.forename: Milena
authors.initials: M
authors.lastname: Mechkarska
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Meetani
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment; D012867:Skin / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D014981:Xenopus / Q000145:classification* / Q000378:metabolism; D029867:Xenopus Proteins / Q000737:chemistry / Q000378:metabolism*; D014982:Xenopus laevis / Q000145:classification / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D029867:Xenopus Proteins
keywords: Frog skin; Host-defense peptide; Taxonomy; Xenopus