Scientists have developed the first genetically modified (GM) chicken, engineered to prevent the spread of the H5N1 avian influenza virus. The researchers at the Roslin Institute of the University of Edingburgh and at the University of Cambridge bred the transgenic chicken to be unable to transmit avian influenza to other chickens.
Prof Helen Sang, from the Roslin Institute said she saw the development as a possible boon for farmers in areas where avian influenza is endemic.
"The results achieved in this study are very encouraging. Using genetic modification to introduce genetic changes that cannot be achieved by animal breeding demonstrates the potential of GM to improve animal welfare in the poultry industry," she said. "This work could also form the basis for improving economic and food security in many regions of the world where bird flu is a significant problem."
* The study, Suppression of Avian Influenza Transmission in Genetically Modified Chickens, was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), and has been published in the latest issue of the journal Science.
How the science works
In their study, the scientists introduced a new gene to a chicken embryo to create a "decoy" module, resembling a primary control section of the bird flu virus. The mechanism which controls the virus's replication mistakenly recognises the decoy as the actual viral genome, interfering with the replication cycle.
Transgenic chickens bred by the scientists were infected with avian flu and became sick. But, importantly, they did not transmit the infection to other chickens kept in the same pen. This remained the case even if the other chickens in the pen were non-GM birds.
"We expect the decoy to work against all strains of avian influenza and that the virus will find it difficult to evolve to escape the effects of the decoy," said Dr Laurence Tiley, senior lecturer in molecular virology at the University of Cambridge.
"This is quite different from conventional flu vaccines, which need to be updated in the face of virus evolution, as they tend only to protect against closely matching strains of virus and do not always prevent spread within a flock."
The technique of using genes to create 'decoy' molecules to prevent the spread of viruses is also applicable for other viruses such as Newcastle Disease and with more research Mareks Disease.
Source: Farmers Weekly Interactive
