title: Genetic Diversity and Population Structure of Theileria annulata in Oman.
abstract: BACKGROUND
  Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle.
  
  
  METHODS
  Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites) representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman.
  
  
  RESULTS
  We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia). A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075, θ = 0.07) were detected when the data for T. annulata parasites in Oman was compared with that previously generated for Turkey and Tunisia.
  
  
  CONCLUSIONS
  Genetic analyses of T. annulata samples representing four geographical regions in Oman revealed a high level of genetic diversity in the parasite population. There was little evidence of genetic differentiation between parasites from different regions, and a high level of genetic diversity was maintained within each sub-population. These findings are consistent with a high parasite transmission rate and frequent movement of animals between different regions in Oman.
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, P.O Box 35 Postal Code 123, Al-Khod, Sultanate of Oman.
authors.forename: Salama
authors.initials: S
authors.lastname: Al-Hamidhi
authors.affiliation: Department of Animal and Veterinary Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O Box 34 Postal Code 123, Al-Khod, Sultanate of Oman.
authors.forename: Mohammed
authors.initials: M
authors.lastname: H Tageldin
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Weir
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, P.O Box 35 Postal Code 123, Al-Khod, Sultanate of Oman.
authors.forename: Amira
authors.initials: A
authors.lastname: Al-Fahdi
authors.affiliation: Department of Animal and Veterinary Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O Box 34 Postal Code 123, Al-Khod, Sultanate of Oman.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Johnson
authors.affiliation: Department of Animal and Veterinary Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O Box 34 Postal Code 123, Al-Khod, Sultanate of Oman.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bobade
authors.affiliation: Ministry of Agriculture and Fisheries, Muscat, Oman.
authors.forename: Badar
authors.initials: B
authors.lastname: Alqamashoui
authors.affiliation: Research Centre in Biodiversity and Genetic Resources (CIBIO), University of Porto, Rua Padre Armando Quintas 7, Vairão, 4485-661, Portugal.
authors.forename: Albano
authors.initials: A
authors.lastname: Beja-Pereira
authors.affiliation: Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Joanne
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Kinnaird
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Brian
authors.initials: B
authors.lastname: Shiels
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Andy
authors.initials: A
authors.lastname: Tait
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, P.O Box 35 Postal Code 123, Al-Khod, Sultanate of Oman; Centre for Immunity, Infection & Evolution. Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Hamza
authors.initials: H
authors.lastname: Babiker
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D005787:Gene Frequency; D056426:Genetic Loci / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D023281:Genomics; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats / Q000235:genetics; D018598:Minisatellite Repeats / Q000235:genetics; D009850:Oman; D011110:Polymorphism, Genetic; D016796:Theileria annulata / Q000235:genetics* / Q000502:physiology
chemical_list: D005819:Genetic Markers