USING THE GENOME TO UNDERSTAND IMMUNOGENETICS OF POULTRY
Location: Avian Disease and Oncology Laboratory
Title: Identifying genetic determinants of host resistance to Marek's disease
Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2011
Publication Date: February 8, 2011
Citation: Zhang, H., Chang, S., Dunn, J.R., Luo, J., Song, J. 2011. Identifying genetic determinants of host resistance to Marek's disease [abstract]. International Plant and Animal Genome Conference PAG XIX, January 15-19, 2011, San Diego, California. Paper #W466. Available: http://www.intl-pag.org/.
Marek's disease (MD) is a contagious disease of poultry induced by an alpha-herpesvirus known as Marek's disease virus (MDV). MD has been controlled by vaccination since the 1970s but it remains a serious potential threat to the world poultry industry since: 1) commercial poultry populations at large are susceptible to MD worldwide, 2) new and more virulent strains of MDV keep emerging, and, 3) wide use of vaccines may have been involved in the evolution of MDV toward higher pathogenicity. Therefore, using host genetic resistance to augment the vaccinal measure is critical to continue keeping MD under control and to sustain the prosperity of the world poultry industry. To advance the understanding of host resistance to MD and identify genetic determinants of MD resistance, we conducted a genome-wide association study, a DNA copy number variation association study, and a candidate gene genotype effect study. A genome-wide association study using a 60K SNP panel in a F2 population identified 172 SNP associated with MD, which are distributed over chromosomes 1, 3, 15, and Z. Within the same F2 population, association between 15 identified copy number variation (CNV) and MD are under evaluation. The genotypes of a candidate gene, tumor virus B gene, in conjunction with the genotypes of an endogenous retrovirus gene, ev21, in relation to MD incidence induced by a vv+ strain of MDV were evaluated. In addition, through collaboration with University of Maryland, two inbred lines of chickens, one relatively resistant (line 63) and the other highly susceptible (line 72) to MD, were assessed for epigenetic differences. DNA methylation pattern differences have been identified between the two lines of chickens. Ongoing projects are aimed to construct a genome-wide map of methylation pattern landscape for the two lines of chickens and to assess any association between DNA methylation patterns and MD. Better understanding should lead to better strategies, which in turn lead to better and more efficient approaches to fight against MD.