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A preliminary study of possible genetic influences on the susceptibility of sheep to Johne's disease
Author(s) -
REDDACLIFF LA,
BEH K.,
McGREGOR H.,
WHITTINGTON RJ
Publication year - 2005
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.2005.tb13087.x
Subject(s) - paratuberculosis , flock , biology , disease , immune system , immunity , genotype , allele , immunology , major histocompatibility complex , immunodiffusion , antigen , mycobacterium , genetics , gene , medicine , pathology , bacteria , paleontology
Objective To investigate possible genetic influences on susceptibility or resistance of sheep to Johne's disease. Design A field and laboratory study of two fine‐wool Merino flocks with a high prevalence of disease due to Mycobacterium avium subsp paratuberculosis infection. Procedure Adult sheep were phenotypically classified as having severe, mild or no disease on the basis of clinical, pathological and cultural tests for paratuberculosis, and as positive or negative in tests for humoral immunity (agar gel immunodiffusion test) or cell mediated immunity (skin test for delayed type hyper‐sensitivity). Correlations with phenotype were sought for polymorphisms at loci within selected immune function genes (NRAMP, MHC complex, IFN‐γ, lysozyme, leukaemia inhibiting factor). Results Possible associations of particular NRAMP and MHC alleles with susceptibility or resistance to Johne's disease were detected. Conclusion If the results of this preliminary study are confirmed in further work, then the use of rams with “resistant” genotypes may assist in the control of Johne's disease in infected flocks.