title: Immunity traits in pigs: substantial genetic variation and limited covariation.
abstract: BACKGROUND
  Increasing robustness via improvement of resistance to pathogens is a major selection objective in livestock breeding. As resistance traits are difficult or impossible to measure directly, potential indirect criteria are measures of immune traits (ITs). Our underlying hypothesis is that levels of ITs with no focus on specific pathogens define an individual's immunocompetence and thus predict response to pathogens in general. Since variation in ITs depends on genetic, environmental and probably epigenetic factors, our aim was to estimate the relative importance of genetics. In this report, we present a large genetic survey of innate and adaptive ITs in pig families bred in the same environment.
  
  
  RESULTS
  Fifty four ITs were studied on 443 Large White pigs vaccinated against Mycoplasma hyopneumoniae and analyzed by combining a principal component analysis (PCA) and genetic parameter estimation. ITs include specific and non specific antibodies, seric inflammatory proteins, cell subsets by hemogram and flow cytometry, ex vivo production of cytokines (IFNα, TNFα, IL6, IL8, IL12, IFNγ, IL2, IL4, IL10), phagocytosis and lymphocyte proliferation. While six ITs had heritabilities that were weak or not significantly different from zero, 18 and 30 ITs had moderate (0.1<h2≤0.4) or high (h2>0.4) heritability values, respectively. Phenotypic and genetic correlations between ITs were weak except for a few traits that mostly include cell subsets. PCA revealed no cluster of innate or adaptive ITs.
  
  
  CONCLUSIONS
  Our results demonstrate that variation in many innate and adaptive ITs is genetically controlled in swine, as already reported for a smaller number of traits by other laboratories. A limited redundancy of the traits was also observed confirming the high degree of complementarity between innate and adaptive ITs. Our data provide a genetic framework for choosing ITs to be included as selection criteria in multitrait selection programmes that aim to improve both production and health traits.
authors.affiliation: INRA, UMR 1313 de Génétique Animale et Biologie Intégrative, Domaine de Vilvert, Jouy-en-Josas, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Flori
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Denis
authors.initials: D
authors.lastname: Laloë
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Lemonnier
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Leplat
authors.forename: Angélique
authors.initials: A
authors.lastname: Teillaud
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Cossalter
authors.forename: Joëlle
authors.initials: J
authors.lastname: Laffitte
authors.forename: Philippe
authors.initials: P
authors.lastname: Pinton
authors.forename: Christiane
authors.initials: C
authors.lastname: de Vaureix
authors.forename: Marcel
authors.initials: M
authors.lastname: Bouffaud
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Mercat
authors.forename: François
authors.initials: F
authors.lastname: Lefèvre
authors.forename: Isabelle P
authors.initials: IP
authors.lastname: Oswald
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bidanel
authors.forename: Claire
authors.initials: C
authors.lastname: Rogel-Gaillard
mesh_terms: D056704:Adaptive Immunity / Q000235:genetics*; D000818:Animals; D001947:Breeding; D016207:Cytokines / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D005819:Genetic Markers; D014644:Genetic Variation; D007113:Immunity, Innate / Q000235:genetics*; D008297:Male; D045705:Mycoplasma hyopneumoniae / Q000276:immunology; D010641:Phenotype; D045729:Pneumonia of Swine, Mycoplasmal / Q000235:genetics / Q000276:immunology / Q000517:prevention & control; D025341:Principal Component Analysis; D012641:Selection, Genetic; D013552:Swine; D013553:Swine Diseases / Q000235:genetics* / Q000276:immunology*; D014611:Vaccination
chemical_list: D016207:Cytokines; D005819:Genetic Markers