Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2010
Publication Date: 10/11/2011
Citation: Casas, E., Garcia, M.D., Wells, J., Smith, T.P.L. 2011. Association of single nucleotide polymorphisms in the ANKRA2 and CD180 genes with bovine respiratory disease and presence of Mycobacterium avium subsp. paratuberculosis. Animal Genetics. 42:571-577. Interpretive Summary: The objective of this study was to replicate and validate previous findings that one end of bovine chromosome 20 was associated with diseases in cattle. Two independent populations were used. One population was recorded for incidence of respiratory disease (pneumonia) and the other population for the presence or absence of the pathogen that causes Johne’s disease in dairy cattle. Genetic markers were selected in two genes with known function in the immune response of livestock. These markers were used to ascertain their association with incidence of the two conditions in both populations. Results from this study show evidence that the region where these genes reside is associated with incidence of diseases in cattle. Further studies will be required to ascertain if these genes, or neighboring genes, are the ones responsible for the difference in disease incidence. The region of chromosome 20 where these genes are located is associated with incidence of disease in cattle.
Technical Abstract: Previous studies have established the presence of genetic variation on bovine chromosome 20 affecting a range of infectious disease-related phenotypes. The objective was to determine if single nucleotide polymorphisms (SNP) in the ANKRA2 and RP105 genes were associated with incidence of bovine respiratory disease (BRD) and presence of Mycobacterium avium subsp. paratuberculosis in cattle. Two independent populations were used. The first population (BRD; N = 90) was composed of 31 half-sib progeny from a Brahman x Angus sire that were treated for bovine respiratory disease. Untreated offspring from the sire were selected to serve as controls. The second population (MAP), of 330 animals of unknown parentage was evaluated for the presence of M. paratuberculosis in ileocecal lymph node and classified as positive or negative, to assess association with active infection with the pathogen. Multiple markers in both genes were assessed for association in these two populations. In the BRD population, five SNP in the ANKRA2 gene were significantly associated (P < 0.05), and two SNP were highly associated (P < 0.01) with incidence of bovine respiratory disease. In addition, two SNP in the RP105 were found to be associated with this trait. In the MAP population, one SNP in the ANKRA2 gene was significantly associated (P < 0.05) with presence or absence of M. paratuberculosis, and an SNP in the RP105 gene was highly associated (P < 0.01) with the trait. Haplotypes, using significant markers in both genes, showed an increased association with both, incidence of bovine respiratory disease (P = 0.0001) in the BRD population and with presence of M. paratuberculosis in the MAP population (P = 0.0032). Markers in the ANKRA2 and RP105 genes are associated with the ability of the animal to cope with pathogens.