The genes of some chickens makes them almost resistant to bird flu according to new research results published by The Pirbright Institute in Surrey.
“Until now, scientists around the world have not paid enough attention to the role the genetics of birds play in the transmission of flu, focusing instead on how the virus itself evolves and infects,” said Pirbright, adding that the new results show that genetics play a key part in whether the birds are susceptible or resistant to the potentially deadly virus.
“It is important to understand how different genetic lines of birds react to influenza viruses, so that we can begin to understand the spread of the disease,” said research leader, Dr Colin Butter, Reader in Bioveterinary Science at the University of Lincoln, who researched influenza viruses while at Pirbright.
“Our results are valuable in emphasising the important role a ‘host’ plays in the spread of avian flu, and also in highlighting a number of factors relating to the chain of infection and control mechanisms which are affected by the route of infection.”
The research involved an examination of two genetically distinct lines of chickens to determine whether genetics played a part in the susceptibility or resistance to infection. This showed that birds that carried the virus, but were genetically resistant to the disease, only shed the virus through their respiratory tract and for a limited period of time. In contrast, birds which were susceptible to the disease, also shed virus in faeces and over a longer time.
The research team also discovered that this was the only relevant means of spreading the virus and that resistant birds were therefore unable to initiate or sustain the chain of transmission.
Further research results suggest that this could be due to a genetic restriction within the animal which stops the virus spreading when inside the body.
Pirbright is now planning additional research to examine the precise biological mechanisms behind the genetic resistance. Researchers believe this could have major implications for poultry breeding, as well as human flu treatments.
The Pirbright work was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and included scientists from the University of Oxford and The Francis Crick Institute in London.
