a preliminary study of genetic factors that influence susceptibility to bovine tuberculosis in the british cattle herd一项初步研究影响对牛结核病的易感性的遗传因素在英国牛羊群.pdfVIP

A Preliminary Study of Genetic Factors That Influence Susceptibility to Bovine Tuberculosis in the British Cattle Herd 1 1¤ 2 2 1 Erin E. Driscoll *, Joseph I. Hoffman , Laura E. Green , Graham F. Medley , William Amos 1 Department of Zoology, University of Cambridge, Cambridge, United Kingdom, 2 Department of Biological Sciences, University of Warwick, Coventry, United Kingdom Abstract Associations between specific host genes and susceptibility to Mycobacterial infections such as tuberculosis have been reported in several species. Bovine tuberculosis (bTB) impacts greatly the UK cattle industry, yet genetic predispositions have yet to be identified. We therefore used a candidate gene approach to study 384 cattle of which 160 had reacted positively to an antigenic skin test (‘reactors’). Our approach was unusual in that it used microsatellite markers, embraced high breed diversity and focused particularly on detecting genes showing heterozygote advantage, a mode of action often overlooked in SNP-based studies. A panel of neutral markers was used to control for population substructure and using a general linear model-based approach we were also able to control for age. We found that substructure was surprisingly weak and identified two genomic regions that were strongly associated with reactor status, identified by markers INRA111 and BMS2753. In general the strength of association detected tended to vary depending on whether age was included in the model. At INRA111 a single genotype appears strongly protective with an overall odds ratio of 2.2, the effect being consistent across nine diverse breeds. Our results suggest that breeding strategies could be devised that would appreciably incre