title: Identification of factor XI deficiency in Holstein cattle in Turkey.
abstract: BACKGROUND
  Factor XI (FXI) is a plasma protein that participates in the formation of blood clots. Factor XI deficiency is autosomal recessive hereditary disorder that may be associated with excess bleeding in Holstein cattle.
  
  
  METHODS
  In this study, 225 Holstein cows reared in Turkey were screened in order to identify FXI genotypes. DNA extractions were obtained from the fresh blood of the cows. Amplicons of FXI exon 12 were obtained by Polymerase Chain Reaction (PCR), and analyzed by 2% agarose gel electrophoresis stained with ethidium bromide. Additionally, all cows were confirmed by DNA sequencing to determine whether or not there was a mutant allele.
  
  
  RESULTS
  Carriers of the FXI deficiency have two DNA fragments of 320 bp and 244 bp in size. The results of our study demonstrated that only four out of the 225 Holstein cows tested in Turkey carried the FXI deficiency. The frequency of the mutant FXI allele and the prevalence of heterozygous cows were found as 0.9% and 1.8%, respectively.
  
  
  CONCLUSIONS
  The DNA-based test determines all genotypes, regardless of phenotype or FXI activity. The mutation responsible for the FXI deficiency had not been detected in Holstein cattle in Turkey before prior to this study. The frequency of the mutant FXI allele needs to be confirmed by carrying out further analyses on cattle in Turkey and the selection programs should be developed to eliminate this genetic disorder.
authors.affiliation: Ankara University, Faculty of Agriculture, Animal Sciences, Ankara, Turkey. hasan_meydan@hotmail.com
authors.forename: Hasan
authors.initials: H
authors.lastname: Meydan
authors.forename: Mehmet A
authors.initials: MA
authors.lastname: Yildiz
authors.forename: Fulya
authors.initials: F
authors.lastname: Ozdil
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Gedik
authors.forename: Ceyhan
authors.initials: C
authors.lastname: Ozbeyaz
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics*; D005172:Factor XI / Q000235:genetics; D005173:Factor XI Deficiency / Q000175:diagnosis / Q000235:genetics / Q000662:veterinary*; D005260:Female; D020022:Genetic Predisposition to Disease; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014421:Turkey
chemical_list: D005172:Factor XI