title: Genetic variability in cysteine protease genes of Haemonchus contortus.
abstract: To increase the existent genetic variability in cysteine proteases, a polymorphism study was performed in Haemonchus contortus by comparing 2 different strains of the parasite: North American (NA) and Spanish (SP) strains. For this purpose, the polymorphism of 5 previously reported genes (AC-1, AC-3, AC-4, AC-5 and GCP-7) were analysed by PCR-SSCP and sequencing procedures. Based on the SSCP results, a total of 20 different alleles were identified for the 5 loci assessed. Except locus AC-5, all the loci were polymorphic. Loci AC-1, AC-3, AC-4 and GCP-7 showed 5, 8, 2 and 4 alleles, respectively. The allelic frequencies ranged from 0.0070 to 0.8560 and were significantly different between strains. In addition, nucleotide diversity analyses showed a significant variation within and between strains. The variations in the nucleotide sequence of the different alleles were translated in some cases into changes in the amino acid sequence. Evidence of genetic variability in cysteine proteases from two different strains of H. contortus for the same set of genes had not been previously reported.
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Veterinary Faculty, University of Las Palmas de Gran Canaria, 35416 Arucas, Las Palmas, Spain. aruiz@dpat.ulpgc.es
authors.forename: A
authors.initials: A
authors.lastname: Ruiz
authors.forename: J M
authors.initials: JM
authors.lastname: Molina
authors.forename: A
authors.initials: A
authors.lastname: Njue
authors.forename: R K
authors.initials: RK
authors.lastname: Prichard
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003546:Cysteine Endopeptidases / Q000235:genetics*; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006189:Haemonchus / Q000201:enzymology* / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009656:North America; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D018807:Polymorphism, Single-Stranded Conformational; D016415:Sequence Alignment; D013030:Spain
chemical_list: D018509:DNA, Helminth; D003546:Cysteine Endopeptidases