The chicken major histocompatibility complex in disease resistance and poultry breeding

Numerous studies confirm that genes in the chicken major histocompatibility complex exert major genetic control over host resistance to autoimmune, viral, bacterial, and parasitic diseases. Examples of major histocompatibility complex associations with traits of growth and reproduction in the chicken are also available. Thus, the major effects of the major histocompatibility complex on the economically important traits of disease resistance, growth, and reproduction make the major histocompatibility complex a valuable subject for intensive analysis in agricultural species. This paper examines, as a model for integration of genetics and immunology, the research on the chicken major histocompatibility complex, which confirmed its role in genetic control of disease resistance, focusing on Marek's disease, a virally induced cancer. Current knowledge of associations of the chicken major histocompatibility complex with specific disease resistance, immune response, and other economic traits are selectively reviewed. Use of major histocompatibility complex typing in the poultry industry, including speculation about future applications, is presented.