Genetic resistance to diseases in poultry: From genetics to genomics

Host and pathogen are in continuous race against each other for their existence in biological system. The host evolves its immune system to produce more potent arsenal in the form of immuno-competent cells and immune effectors to meet the new and varied pathogen challenges. Simultaneously, the pathogen also mutates to evolve mechanisms to evade or suppress or defunct or damage the immune system and to develop resistance against medicaments. As a result, the new pathogens emerge as a more dreadful threat, afflicting wider range of hosts. The man made interventions through development of vaccines and medicaments have significantly contributed in containment of diseases however genetics of host also a profound effect resisting or killing and removing the pathogens from system. Several selection experiments have been performed in several animal species. Chicken has served as the model species for conducting research on disease resistance. The researches in the areas of diseases resistance have traversed through different phases and witnessed several innovations involving recent technologies. Different pathways and systems, genes and gene products in a cascade of reaction play pivotal role mounting host response against invading pathogen. The present article reviews the research works carried in the area of disease resistance particularly in chicken. The selection for disease resistance may therefore be helpful in containment of disease with use of limited vaccine and medicaments thereby helping in resolving the problems of residues in poultry products.