DNA analysis research could help breed chickens that are more resistant to damaging viral infections like avian influenza, Marek’s disease, infectious bursal disease and infectious bronchitis virus, according to a study published in the journal Animal Genetics.
“Between them, these viruses are responsible for huge economic losses to the poultry industry. This could be through chicken mortality, decreased production or vaccination costs. Currently, there is no cure for these diseases,” Jacqueline Smith, Roslin Institute at the University of Edinburgh, said.
DNA changes with disease resistance
The study evaluated the genetic differences between chickens that naturally display greater immunity against viruses versus those that are more likely to develop viral infections.
These findings were compared with a standard reference chicken genome to identify how variations in these regions affected immunity and the bird’s response to infection.
“Depending on what part of the gene sequence we found to be different, we could then identify whether the mutation might cause a change to the protein encoded by that gene or whether it might cause a change in how the protein would be regulated in the chicken’s immune system,” she said.
“We identified a set of genetic differences in the interferon genes in these birds, and with knowledge of how each type of bird reacts to each virus, we can highlight DNA changes which might be potentially important for disease resistance.”
Improving disease resistance in chickens and people
In the future, this research could be valuable in breeding chickens that are more resistant to disease or in the development of drugs or vaccines against viral infections.
“If we can identify DNA markers that are important for increased disease resistance, chickens can be selectively bred to be more resilient to disease. This would have a profound effect on both animal welfare and economic savings for the industry,” Smith explained.
Humans could also benefit from this research, she added, noting that “although different in some ways, the interferon system is similar in many ways in both chickens and in humans. The more we understand about how immune genes work, and their role in the immune system, the better equipped we are to be able to combat disease.”