title: Admixture mapping of tuberculosis and pigmentation-related traits in an African-European hybrid cattle population.
abstract: Admixture mapping affords a powerful approach to genetic mapping of complex traits and may be particularly suited to investigation in cattle where many breeds and populations are hybrids of the two divergent ancestral genomes, derived from Bos taurus and Bos indicus. Here we design a minimal genome wide SNP panel for tracking ancestry in recent hybrids of Holstein-Friesian and local Arsi zebu in a field sample from a region of high bovine tuberculosis (BTB) endemicity in the central Ethiopian highlands. We first demonstrate the utility of this approach by mapping the red coat color phenotype, uncovering a highly significant peak over the MC1R gene and a second peak with no previously known candidate gene. Secondly, we exploit the described differential susceptibility to BTB between the ancestral strains to identify a region in which Bos taurus ancestry associates, at suggestive significance, with skin test positivity. Interestingly, this association peak contains the toll-like receptor gene cluster on chromosome 6. With this work we have shown the potential of admixture mapping in hybrid domestic animals with divergent ancestral genomes, a recurring condition in domesticated species.
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin Dublin, Ireland.
authors.forename: Yonas
authors.initials: Y
authors.lastname: Kassahun
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin Dublin, Ireland.
authors.forename: Valeria
authors.initials: V
authors.lastname: Mattiangeli
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University Addis Ababa, Ethiopia ; Armauer Hansen Research Institute Addis Ababa, Ethiopia.
authors.forename: Gobena
authors.initials: G
authors.lastname: Ameni
authors.affiliation: Armauer Hansen Research Institute Addis Ababa, Ethiopia.
authors.forename: Elena
authors.initials: E
authors.lastname: Hailu
authors.affiliation: Armauer Hansen Research Institute Addis Ababa, Ethiopia.
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
authors.affiliation: Centre for Molecular Microbiology and Infection, Imperial College London London, UK.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Young
authors.affiliation: TB Research Group, Animal and Plant Health Agency Addlestone, UK.
authors.forename: R Glyn
authors.initials: RG
authors.lastname: Hewinson
authors.affiliation: TB Research Group, Animal and Plant Health Agency Addlestone, UK.
authors.forename: H Martin
authors.initials: HM
authors.lastname: Vordermeier
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin Dublin, Ireland.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Bradley
keywords: Bos indicus; Bos taurus; Mycobacterium bovis; SNPs; admixture mapping