50 Gene Editing Applications in Livestock Production

Abstract

Abstract Gene editing is a technology that allows changes in the DNA of organisms from plants to animals, to humans. Its application in research has been around for a long time, and different techniques were developed over the years such as Zinc-finger nucleases, TALENs and more recently the CRISPR-Cas9 system. The latter has gained popularity for being much simpler to implement and at the same time being able to perform more precise edits with less off targets. Scientists and farmers have been using genetics selection to improve productivity and sustainability of agriculture for many decades using information from phenotypes, pedigrees, and more recently genomic information. With the increasing demand for food production, the investigation and adoption of new technologies will continue to drive and accelerate genetic improvement in animals and plants to meet consumer demands and expectations. A lot of effort has been devoted to developing gene editing research and applications for a variety of traits to improve production, health, and wellbeing of farmed animals. Although gene editing and more specifically the CRISPR technology was met with great expectations for genetic improvements in animals, a few challenges are still unresolved and are under constant research and development. For instance, many of the economically relevant traits for animal production are controlled by many genes with small effects (polygenic traits). For these traits, editing many loci would be required to make significant improvements, which adds a lot of complexity for the current technologies. Another challenge for further development, and deployment of this technology has been on the regulatory side, in which legislation for the use of gene edited animals for food production is still under development, and many regulatory aspects are not clear. These have been largely addressed on case-by-case basis, with recent approvals for Atlantic Salmon (fast growing), swine (hypoallergenic) and beef cattle (slick coat) being granted for specific use cases. Other examples of applications of gene editing are the coat color change, and creation of polled animals in cattle, which target improvements on environmental adaptability and animal welfare. In swine, researchers have been working on developing pigs that are resistant to the porcine reproductive and respiratory syndrome (PRRS) which could lead to a great health and economic benefits for the swine industry. These are a few examples of how gene editing could help improve disease resistance, well-being and climate adaptation traits for many livestock and aquaculture species in the future. Further refinements of the technology, the development of policies and legislation, and strategies for deployment in commercial applications will continue to be key aspects to guide a safe and responsible use of gene editing in livestock production.