SCIENTISTS have used gene editing techniques to identify and change parts of chicken DNA that could limit the spread of the bird flu virus in the animals.

Researchers were able to restrict – but not wholly block – the virus from infecting chickens by altering a small section of their DNA.

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In the trials, birds showed no signs that the change in their DNA had any impact on their health or well-being.

Scientists from the University of Edinburgh, Imperial College London and the Pirbright Institute bred the chickens using gene editing techniques to alter the section of DNA responsible for producing protein molecules that flu viruses “hijack” to help replicate themselves.

Exposed to a “normal” dose of the H9N2-UDL strain of avian influenza, nine out of 10 birds remained uninfected, and there was no spread to other chickens.

Dosage

The research team then exposed the gene-edited birds to an artificially high dose of avian influenza virus to further test their resilience.

When exposed to the high dose, half of the group – five out of 10 birds – became infected.

However, the gene edit did provide some protection, with the amount of virus in the infected gene-edited chickens much lower than the level typically seen during infection in non-gene-edited chickens.

Onward spread

The gene edit also helped to limit the onward spread of the virus to just one of four non-gene-edited chickens placed in the same incubator. There was no transmission to gene-edited birds.

Bird flu is a major global threat with a devastating impact on both farmed and wild bird populations.

In the UK alone, the current outbreak of H5N1 bird flu has decimated seabird populations and cost the poultry industry more than £100 million in losses.

Gene editing

The study’s principal investigator, Mike McGrew, from the University of Edinburgh’s Roslin Institute, said: “Bird flu is a great threat to bird populations. Vaccination against the virus poses a number of challenges, with significant practical and cost issues associated with vaccine deployment.

“Gene-editing offers a promising route towards permanent disease resistance, which could be passed down through generations, protecting poultry and reducing the risks to humans and wild birds.”

The research was funded by UKRI-BBSRC, which also provides strategic funding to The Roslin Institute, and was supported by Edinburgh Innovations, the University’s commercialisation service.

The study is published in the journal Nature Communications: https://www.nature.com/articles/s41467-023-41476-3