title: The genomic architecture of resistance to Campylobacter jejuni intestinal colonisation in chickens.
abstract: BACKGROUND
  Campylobacter is the leading cause of foodborne diarrhoeal illness in humans and is mostly acquired from consumption or handling of contaminated poultry meat. In the absence of effective licensed vaccines and inhibitors, selection for chickens with increased resistance to Campylobacter could potentially reduce its subsequent entry into the food chain. Campylobacter intestinal colonisation levels are influenced by the host genetics of the chicken. In the present study, two chicken populations were used to investigate the genetic architecture of avian resistance to colonisation: (i) a back-cross of two White Leghorn derived inbred lines [(61 x N) x N] known to differ in resistance to Campylobacter colonisation and (ii) a 9(th) generation advanced intercross (61 x N) line.
  
  
  RESULTS
  The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait. A back-cross experiment using 1,243 fully informative single nucleotide polymorphism (SNP) markers revealed quantitative trait loci (QTL) on chromosomes 7, 11 and 14. In the advanced intercross line study, the location of the QTL on chromosome 14 was confirmed and refined and two new QTLs were identified located on chromosomes 4 and 16. Pathway and re-sequencing data analysis of the genes located in the QTL candidate regions identified potential pathways, networks and candidate resistance genes. Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.
  
  
  CONCLUSIONS
  Campylobacter resistance in chickens is a complex trait, possibly involving the Major Histocompatibility Complex, innate and adaptive immune responses, cadherins and other factors. Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK. Androniki.psifidi@roslin.ed.ac.uk.
authors.forename: A
authors.initials: A
authors.lastname: Psifidi
authors.affiliation: The Pirbright Institute, Genetics & Genomics Group, Surrey, GU240NF, UK.
authors.forename: M
authors.initials: M
authors.lastname: Fife
authors.affiliation: The Pirbright Institute, Genetics & Genomics Group, Surrey, GU240NF, UK.
authors.forename: J
authors.initials: J
authors.lastname: Howell
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: O
authors.initials: O
authors.lastname: Matika
authors.affiliation: Jenner Institute, Nuffield Department of Clinical Medicine, The Centre for Cellular and Molecular Physiology, Roosevelt Drive, Headington, Oxford, OX3 7BN, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: van Diemen
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: R
authors.initials: R
authors.lastname: Kuo
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Hocking
authors.affiliation: The Pirbright Institute, Genetics & Genomics Group, Surrey, GU240NF, UK.
authors.forename: N
authors.initials: N
authors.lastname: Salmon
authors.affiliation: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Jones
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Hume
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.|Scotland's Rural College, Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: G
authors.initials: G
authors.lastname: Banos
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Stevens
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
authors.forename: P
authors.initials: P
authors.lastname: Kaiser
mesh_terms: D000818:Animals; D002169:Campylobacter Infections / Q000235:genetics / Q000662:veterinary*; D016123:Campylobacter jejuni; D002645:Chickens / Q000235:genetics* / Q000382:microbiology; D003433:Crosses, Genetic; D055106:Genome-Wide Association Study; D060005:Genotyping Techniques; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011201:Poultry Diseases / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci; D012481:Salmonella Infections, Animal / Q000235:genetics* / Q000382:microbiology
keywords: Advanced intercross; Back-cross; Campylobacter; Chicken; Genome-wide association; Quantitative trait; Resistance