Gene-edited chickens may help limit bird flu

When avian influenza, or bird flu, strikes, it can be hazardous to human health and potentially devastating for the poultry industry.

Unlike some animal diseases, some strains of bird flu can affect humans, and over the years numerous high-profile outbreaks have garnered attention to these viruses. And every time there’s a reported case, poultry producers perk up their ears and bolster down their biosecurity protocols, trying to protect their flock.

Last week, scientists in Scotland reported on their recent work on one way to stop a bird flu epidemic: gene-edited chickens.

Researchers from the Roslin Institute of the University of Edinburgh say that, if all goes well, the first chicks in their gene-editing study will hatch later this year. CRISPR technology has allowed the research team to remove parts of the birds’ DNA, specifically the protein that the flu virus depends on in order to infect its host.

The protein in question is encoded by the gene ANP32. Previous research has shown that simply removing this gene has made cells immune to flu viruses.

“We have identified the smallest change that will stop the virus in its tracks,” said project co-lead Wendy Barclay.

Because humans often get bird flu from the poultry they raise or consume, the scientists hope that a flu-resistant chickens will act as a “buffer” between wild birds, which often spread flu viruses to domestic flocks, and humans. They would also save poultry producers the pain of needing to cull birds during outbreaks.

“If we could prevent influenza virus crossing from wild birds into chickens, we would stop the next pandemic at its source,” said Barclay.

How does CRISPR work?

Gene-editing involved hands-on manipulation of DNA. One of the biggest ways scientists do this today is using the CRISPR method, which stands for clustered regularly interspaced short palindromic repeats. You can see why they made an acronym.

This technology mimics a process found in the original gene-editing scientists: bacteria. In this process, bacteria capture snippets of DNA from invading viruses, and use them to create entirely new DNA segments. These segments allow bacteria to maintain a record of the viruses that have attacked them before, so if it happens again, the bacteria can produce RNA segments to target the enemy virus DNA. The bacteria then uses the Cas9 enzyme, or a similar enzyme, to halt the invading DNA.

In the lab, scientists create an RNA segment with a built-in “guide” DNA sequence. The guide sequence binds to a targeted DNA sequence in a specific genome, as well as the Cas9 enzyme. That modified RNA recognizes the DNA segment, and Cas9 cuts the DNA at the targeted location. At this point, scientists take advantage of the cell’s natural ability to repair DNA in order to add, delete, or modify segments of genetic material.

Neogen’s advanced genomics services provide poultry producers with the information they need to better understand their flock and made informed breeding decisions. See our website for more information, or check out our page on biosecurity solutions for in and around the poultry house, including disinfectants proven to kill flu-causing viruses.