title: Biochemical, genetic and physiological characterization of venom components from two species of scorpions: Centruroides exilicauda Wood and Centruroides sculpturatus Ewing.
abstract: Current literature concerning the taxonomic names of two possibly distinct species of scorpions from the genus Centruroides (sculpturatus and/or exilicauda) is controversial. This communication reports the results of biochemical, genetic and electrophysiological experiments conducted with C. exilicauda Wood of Baja California (Mexico) and C. sculpturatus Ewing of Arizona (USA). The chromatographic profile fractionation of the soluble venom from both species of scorpions is different. The N-terminal amino acid sequence for nine toxins of C. exilicauda was determined and compared with those from C. sculpturatus. Lethality tests conducted in mice support the idea that C. exilicauda venom should be expected to be medically less important than C. sculpturatus. Thirteen genes from the venomous glands of the scorpion C. exilicauda were obtained and compared with previously published sequences from genes of the species C. sculpturatus. Genes coding for cytochrome oxidase I and II of both species were also sequenced. A phylogenetic tree was generated with this information showing important differences between them. Additionally, the results of electrophysiological assays conducted with the venom from both species on the Ca(2+)-dependent K(+)-channels, showed significant differences. These results strongly support the conclusion that C. exilicauda and C. sculpturatus are in fact two distinct species of scorpions.
authors.affiliation: Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico.
authors.forename: Norma A
authors.initials: NA
authors.lastname: Valdez-Cruz
authors.forename: Sonia
authors.initials: S
authors.lastname: Dávila
authors.forename: Alexei
authors.initials: A
authors.lastname: Licea
authors.forename: Miguel
authors.initials: M
authors.lastname: Corona
authors.forename: Fernando Z
authors.initials: FZ
authors.lastname: Zamudio
authors.forename: Jesús
authors.initials: J
authors.lastname: García-Valdes
authors.forename: Leslie
authors.initials: L
authors.lastname: Boyer
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001130:Arizona; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D004594:Electrophysiology / Q000379:methods; D005260:Female; D008800:Mexico; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D010802:Phylogeny; D021122:Protein Subunits; D012604:Scorpion Venoms / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity*; D012605:Scorpions / Q000145:classification / Q000502:physiology*; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000187:drug effects; D013045:Species Specificity; D014118:Toxins, Biological / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D004272:DNA, Mitochondrial; D021122:Protein Subunits; D012604:Scorpion Venoms; D015222:Sodium Channels; D014118:Toxins, Biological; D003576:Electron Transport Complex IV