Scientists from Germany and Scotland have pinpointed a gene in the DNA of pigs that is needed by a deadly virus to cause infection, according to a news release from the Roslin Institute.

The discovery could help researchers understand the development of pigs resistant to African swine fever (ASF).

ASF has killed more than 200 million pigs worldwide, is a major issue across Asia, and has the potential to cause major outbreaks in Europe and America.

A team of researchers found that the gene, which is involved in the pig immune system, is essential for replication of the ASF virus. The finding opens the possibility of using gene editing to amend the gene, enabling the development of ASF-resistant pigs. 

There is currently no treatment available for ASF. 

Immunity proteins

A team led by the Friedrich-Loeffler Institute, in cooperation with the Roslin Institute, sought to pinpoint which pig genes were needed for the virus to replicate.

In lab tests they examined a collection of pig cells, each one edited to lack a specific gene compared with the rest, to observe how they responded to the African swine fever virus.

Their research revealed a number of genes that produce proteins associated with immune response to infections, known as the MHC-II complex, as being key to allowing the virus to take hold. A single protein within the complex, known as SLA-DM, is crucial for the replication of the virus in cells. 

The researchers believe that editing the SLA-DM gene could enable the development of ASF-resistant pigs. 

"This collaboration brings together the Friedrich-Loeffler Institute’s capacity to study ASF virus in the lab, and gene-editing tools developed at the Roslin Institute," said Katrin Pannhorst of the Friedrich-Loeffler-Institute.

"Our study points to genes that are candidates for editing to develop pigs resistant to African Swine Fever," added Finn Grey of the Roslin Institute. "Our study identifies target genes for editing to develop pigs resistant to African Swine Fever. Although more work is required, this finding represents an important first step towards the generation of ASF-resistant pigs."

The study was published in Scientific Reports.