title: Thrombostasin isoform frequency in a Central Texas field population of the horn fly, Haematobia irritans.
abstract: Thrombostasin is an anti-thrombin factor that plays a role in successful feeding of the horn fly, Haematobia irritans. It has been isolated and characterized from saliva, and polymorphisms in the gene coding sequence have been previously reported. In the present study, the thrombostasin gene was analyzed from 60, field-collected flies from Camp Stanley, Texas and the allele and genotype frequencies were compared with previously published data for an Alabama field collection and a Texas in vitro colony-reared collection. Significant differences in genotype frequency and extent of genotypic diversity observed between the Alabama and Camp Stanley field collections may be attributable to host genetic differences. In addition, bull calves that were phenotyped as either high- or low-carriers were parasitized by horn flies that displayed a significantly different genotype distribution, supporting a possible explanation for horn fly host selection behavior, as evidenced by thrombostasin sequence analysis of 95 additional horn flies collected from respective hosts.
authors.affiliation: USDA-ARS, Knipling Bushland U.S. Livestock Insect Research Laboratory, 2700 Fredericksburg Road, Kerrville, TX 78028, United States. pia.untalan@ars.usda.gov
authors.forename: Pia M
authors.initials: PM
authors.lastname: Untalan
authors.forename: John H
authors.initials: JH
authors.lastname: Pruett
authors.forename: Heather N
authors.initials: HN
authors.lastname: Atteberry
authors.forename: C Dayton
authors.initials: CD
authors.lastname: Steelman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics / Q000469:parasitology*; D017931:DNA Primers / Q000737:chemistry; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006790:Host-Parasite Interactions / Q000502:physiology; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009117:Muscidae / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000662:veterinary; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D013781:Texas
chemical_list: D017931:DNA Primers; D019476:Insect Proteins; D020033:Protein Isoforms; C439004:Thrombostasin protein, Haematobia irritans