Researchers have developed a novel way to protect chickens from avian influenza, a deadly disease that affects millions of poultry worldwide. By using gene editing technology, they have created chickens that are partially resistant to the virus, reducing its replication and transmission.
How gene editing works
The researchers used a technique called CRISPR/Cas9 to make precise changes in the DNA of chicken cells. They targeted three genes that encode for a protein called ANP32, which is essential for the virus to infect and multiply in the cells. By disrupting these genes, they reduced the amount of ANP32 protein available for the virus to use.
The gene-edited cells were then used to generate chickens through a process called primordial germ cell (PGC) transfer. PGCs are cells that can give rise to sperm or eggs in animals. By injecting gene-edited PGCs into chicken embryos, the researchers created chickens that inherited the modified genes.
The results of the experiment
The researchers tested the resistance of the gene-edited chickens to avian influenza by exposing them to different doses and strains of the virus. They found that most of the gene-edited chickens showed no signs of infection when exposed to a typical dose of a low-pathogenic strain of the virus. In contrast, all of the unedited control chickens became infected and shed the virus.
The gene-edited chickens also showed reduced susceptibility to a high-pathogenic strain of the virus, which can cause severe disease and death in poultry. However, some of them still got infected and shed the virus, indicating that the resistance was not complete.
The researchers also analyzed the gene expression and immune response of the gene-edited chickens. They found that the gene editing did not cause any major changes in the overall transcriptome or immune system of the chickens. They also did not observe any adverse effects on the health or fertility of the gene-edited chickens.
The implications and challenges of gene editing
The study demonstrates that gene editing can be used to create avian influenza-resistant chickens, which could potentially prevent the spread of the disease on farms and reduce its economic and health impacts. The researchers estimate that it would take about three years to develop fully resistant chickens by making further modifications to their genes.
However, there are also some challenges and limitations associated with gene editing as a disease control strategy. For instance, the technique requires specialized equipment and expertise, which may not be widely available or affordable for many poultry producers. Moreover, there are ethical and regulatory issues that need to be addressed before gene-edited animals can be approved for commercial use.
The researchers also acknowledge that gene editing is not a silver bullet solution for avian influenza, as the virus can evolve and adapt to overcome resistance. Therefore, they emphasize that gene editing should be combined with other measures such as biosecurity, surveillance, and vaccination to effectively control avian influenza.
