Pigs developed with classical swine fever resistance
CSF is endemic in parts of Asia, Africa, Latin America and Europe.
A new gene editing project has successfully produced pigs that are resistant to classical swine fever (CSF).
The research, conducted by the Roslin Institute, could offer a new approach to contagious disease control for a wide range of livestock.
CSF is a highly contagious, often fatal, disease, which has a significant impact on global pig farming. Although it is not currently found in the UK, there have been significant outbreak in parts of Asia, Africa, Latin America and Europe.
This has led to trade bans and serious financial losses for farmers.
Before they began producing the gene-edited pigs, Roslin Institute researchers worked with collaborators to examine how viruses including CSF, known as pestiviruses, interact with pig cells.
Researchers particularly focused on a key pig protein called DNAJC14, which plays an important role in the virus replication process. Lab studies found that altering the gene which produced this protein therefore prevented the virus from reproducing.
Based on this finding, the team surmised that the same genetic change in live animals could result in livestock which are resistant to the viruses.
In the live trial, scientists made a precise change to part of the DNAJC14 gene in pig embryos. This would prevent the virus from using pig cells to produce its own viral proteins.
These embryos were then implanted into surrogate mothers.
Once the gene-edited pigs had reached adulthood, they were exposed to the CSF virus. After several weeks of observation, researchers found that these pigs displayed no signs of viral infection.
Meanwhile pigs which had not undergone gene editing, when exposed to the virus, displayed the typical signs of infection.
Although there are vaccines for CSF, control is challenging due to the virus’ persistence. It can also transmit across species, with the pestivirus family including bovine viral diarrhoea virus in cattle and border disease virus in sheep.
The gene-edit method could therefore offer a new disease control technique for all livestock, including cows and sheep.
Simon Lillico, core scientist at the Roslin Institute, said: “While previous research had identified this protein’s role in cell cultures, translating that into living animals is a major step, and one that requires the infrastructure to breed, monitor, and safely test gene-edited livestock.
“Our Large Animal Research and Imaging Facility allows us to gene edit and assess a variety of livestock species, with colleagues at the Animal and Plant Health Agency providing expertise and biosecure facilities for this viral challenge.”
The full study can be found in the journal Science Direct.
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