Peptidomic analysis of skin secretions from Rana heckscheri and Rana okaloosae provides insight into phylogenetic relationships among frogs of the Aquarana species group.
The members of the Aquarana (or Rana catesbeiana species group) form a monophyletic group comprising seven species: R. catesbeiana, Rana clamitans, Rana grylio, Rana virgatipes, Rana septentrionalis, Rana heckscheri and Rana okaloosae. Previous work has led to structural characterization of the antimicrobial peptides present in electrically-stimulated skin secretions from the first five species listed and this study presents the primary structures of orthologs from the river frog R. heckscheri and the Florida bog frog R. okaloosae. Peptidomic analysis of R. heckscheri and R. okaloosae skin secretions led to the identification of peptides with antimicrobial activity belonging to the ranalexin, ranatuerin-2, and temporin families. In addition, a peptide (GFLDIIKDTGKDFAVKILNNLKCKLAGGCPR) was isolated from R. okaloosae whose primary structure identified it as a member of the palustrin-2 family. Consistent with previous data based upon morphological analysis and comparisons of the nucleotide sequences of mitochondrial and ribosomal genes, cladistic analysis based upon a comparison of the amino acid sequences of antimicrobial peptides indicates a sister-group relationship between R. heckscheri and R. grylio and a close, but less well defined, phylogenetic relationship between R. okaloosae and R. clamitans.
Conlon
J Michael
JM
Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates. jmconlon@uaeu.ac.ae
Coquet
Laurent
L
Leprince
Jérôme
J
Jouenne
Thierry
T
Vaudry
Hubert
H
Kolodziejek
Jolanta
J
Nowotny
Norbert
N
Bevier
Catherine R
CR
Moler
Paul E
PE
D000470:Alkaloids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000818:Animals; D023181:Antimicrobial Cationic Peptides; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011898:Ranidae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D012867:Skin / Q000378:metabolism*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000470:Alkaloids; D029845:Amphibian Proteins; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D010456:Peptides, Cyclic; D011506:Proteins; C121230:ranatuerin; C104501:temporin; C086618:ranalexin; C099474:palustrine