Scientists have uncovered genetic clues that could help protect chickens from deadly bird flu outbreaks.
In a study of chickens that survived a major outbreak of highly infectious avian influenza in 2015, researchers found several areas of the chickens’ DNA that may influence natural resistance.
Using blood samples, the Roslin Institute team analysed the DNA from chickens that survived this viral outbreak and compared them with that of uninfected, presumed-susceptible birds, seeking differences that could reveal genes linked to resistance.
Results uncovered specific regions across nine different areas of the chicken genome where genetic variations appeared to play a role.
Although no single gene fully explained why some chickens survived, the study pinpointed several genes likely associated with the immune system and the birds’ response to the virus.
This work offers a first step toward breeding chickens with greater resilience to avian flu, which would improve both bird welfare and the stability of the poultry industry.
Genetic resilience
The chickens studied survived a particularly lethal avian flu outbreak, with a mortality rate of over 99 per cent, resulting in large economic impacts on poultry farmers across the USA.
Some of the genes identified in these chickens, including one known as ANP32A, are already known to play a role in how animals respond to bird flu.
This suggests researchers are on the right track, as the presence of a gene with a known role in viral resistance supports the idea that the other newly-identified genes may also be relevant to defence against bird flu.
Poultry health
With highly pathogenic avian influenza (HPAI) outbreaks becoming more common worldwide and infecting a wider host-range, further research could help scientists develop strategies to protect poultry and inform public health.
This research has been published in the International Journal of Molecular Sciences, in collaboration with industrial partners, Hy-line International (USA) and colleagues in Warsaw, Poland and Iowa State University, USA.
The project was funded by a grant from the Iowa Egg Industry Center and the BBSRC.
Dr Jacqueline Smith said:
“Chickens are extremely vulnerable to highly pathogenic strains of avian flu, so being able to examine DNA from a few birds that survived, provided us with a unique opportunity to try and understand the genetics underlying resistance.
“This research gives us our first look at how the host response may enable birds to fight off infection—something we’re only beginning to understand now.”