Genetic modification of food animals

Ovarian overexpression of ASMT gene increases follicle numbers in transgenic sheep: Association with lipid metabolism

Melatonin plays an important role in mammalian reproductive activities, to further understand the effects of endogenous melatonin on functions of ovary, the transgenic sheep with overexpression of melatonin synthetic enzyme gene ASMT in ovary were generated. The results showed that total melatonin content in follicular fluid of transgenic sheep was significantly greater than that in the wild type. Accordingly, the follicle numbers of transgenic sheep were also significantly greater than those in the WT. The results of follicular fluid metabolites sequencing showed that compared with WT, the differential metabolites of the transgenic sheep were significantly enriched in several signaling pathways, the largest number of metabolites was lipid metabolism pathway and the main differential metabolites were lipids and lipoid molecules. SMART-seq2 were used to analyze the oocytes and granulosa cells of transgenic sheep and WT sheep. The main differential enrichment pathway was metabolic pathway, in which lipid metabolism genes accounted for the majority. In conclusion, this is the first report to show that ovary overexpression of ASMT increased local melatonin production and follicle numbers. These results may imply that ASMT plays an important role in follicle development and formation, and melatonin intervention may be a potential method to promote this process.

Genetic improvement in edible fish: status, constraints, and prospects on CRISPR-based genome engineering

Conventional selective breeding in aquaculture has been effective in genetically enhancing economic traits like growth and disease resistance. However, its advances are restricted by heritability, the extended period required to produce a strain with desirable traits, and the necessity to target multiple characteristics simultaneously in the breeding programs. Genome editing tools like zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) are promising for faster genetic improvement in fishes. CRISPR/Cas9 technology is the least expensive, most precise, and well compatible with multiplexing of all genome editing approaches, making it a productive and highly targeted approach for developing customized fish strains with specified characteristics. As a result, the use of CRISPR/Cas9 technology in aquaculture is rapidly growing, with the main traits researched being reproduction and development, growth, pigmentation, disease resistance, trans-GFP utilization, and omega-3 metabolism. However, technological obstacles, such as off-target effects, ancestral genome duplication, and mosaicism in founder population, need to be addressed to achieve sustainable fish production. Furthermore, present regulatory and risk assessment frameworks are inadequate to address the technical hurdles of CRISPR/Cas9, even though public and regulatory approval is critical to commercializing novel technology products. In this review, we examine the potential of CRISPR/Cas9 technology for the genetic improvement of edible fish, the technical, ethical, and socio-economic challenges to using it in fish species, and its future scope for sustainable fish production.

Developing algae as a sustainable food source

Current agricultural and food production practices are facing extreme stress, posed by climate change and an ever-increasing human population. The pressure to feed nearly 8 billion people while maintaining a minimal impact on the environment has prompted a movement toward new, more sustainable food sources. For thousands of years, both the macro (seaweed and kelp) and micro (unicellular) forms of algae have been cultivated as a food source. Algae have evolved to be highly efficient at resource utilization and have proven to be a viable source of nutritious biomass that could address many of the current food production issues. Particularly for microalgae, studies of their large-scale growth and cultivation come from the biofuel industry; however, this knowledge can be reasonably translated into the production of algae-based food products. The ability of algae to sequester CO₂ lends to its sustainability by helping to reduce the carbon footprint of its production. Additionally, algae can be produced on non-arable land using non-potable water (including brackish or seawater), which allows them to complement rather than compete with traditional agriculture. Algae inherently have the desired qualities of a sustainable food source because they produce highly digestible proteins, lipids, and carbohydrates, and are rich in essential fatty acids, vitamins, and minerals. Although algae have yet to be fully domesticated as food sources, a variety of cultivation and breeding tools exist that can be built upon to allow for the increased productivity and enhanced nutritional and organoleptic qualities that will be required to bring algae to mainstream utilization. Here we will focus on microalgae and cyanobacteria to highlight the current advancements that will expand the variety of algae-based nutritional sources, as well as outline various challenges between current biomass production and large-scale economic algae production for the food market.

Overexpression of ASMT likely enhances the resistance of transgenic sheep to brucellosis by influencing immune-related signaling pathways and gut microbiota

Melatonin is a pleiotropic molecule with a variety of biological functions, which include its immunoregulatory action in mammals. Brucellosis is a worldwide endemic zoonotic disease caused by the Brucella, which not only causes huge economic losses for the livestock industry but also impacts human health. To target this problem, in current study, two marker-free transgenic sheep overexpressing melatonin synthetic enzyme ASMT (acetylserotonin O-methyltransferase) gene were generated and these melatonin enrich transgenic sheep were challenged by Brucella infection. The results showed that the serum melatonin concentration was significantly higher in transgenic sheep than that of wild type (726.92 ± 70.6074 vs 263.10 ± 34.60 pg/mL, P < .05). Brucella challenge test showed that two thirds (4/6) of the wild-type sheep had brucellosis, while none of the transgenic sheep were infected. Whole-blood RNA-seq results showed that differential expression genes (DEGs) were significantly enriched in natural killer cell-mediated cytotoxicity, phagosome, antigen processing, and presentation signaling pathways in overexpression sheep. The DEGs of toll-like receptors (TLRs) and NOD-like receptors (NLRs) families were verified by qPCR and it showed that TLR1, TLR2, TLR7, CD14, NAIP, and CXCL8 expression levels in overexpression sheep were significantly higher and NLRP1, NLRP3, and TNF expression levels were significantly lower than those of wild type. The rectal feces were subjected to 16S rDNA amplicon sequencing, and the microbial functional analysis showed that the transgenic sheep had significantly lower abundance of microbial genes related to infectious diseases compared to the wild type, indicating overexpression animals are likely more resistant to infectious diseases than wild type. Furthermore, exogenous melatonin treatment relieved brucellosis inflammation by upregulating anti-inflammatory cytokines IL-4 and downregulating pro-inflammatory IL-2, IL-6, and IFN-γ. Our preliminary results provide an informative reference for the study of the relationship between melatonin and brucellosis.

Comparison of Gene Editing Versus Conventional Breeding to Introgress the POLLED Allele Into the Tropically Adapted Australian Beef Cattle Population

Dehorning is the process of physically removing horns to protect animals and humans from injury, but the process is costly, unpleasant, and faces increasing public scrutiny. Genetic selection for polled (hornless), which is genetically dominant to horned, is a long-term solution to eliminate the need for dehorning. However, due to the limited number of polled Australian Brahman bulls, the northern Australian beef cattle population remains predominantly horned. The potential to use gene editing to produce high-genetic-merit polled cattle was recently demonstrated. To further explore the concept, this study simulated introgression of the POLLED allele into a tropically adapted Australian beef cattle population via conventional breeding or gene editing (top 1% or 10% of seedstock bulls/year) for 3 polled mating schemes and compared results to baseline selection on genetic merit (Japan Ox selection index, $JapOx) alone, over the course of 20 years. The baseline scenario did not significantly decrease the 20-year HORNED allele frequency (80%), but resulted in one of the fastest rates of genetic gain ($8.00/year). Compared to the baseline, the conventional breeding scenarios where polled bulls were preferentially used for breeding, regardless of their genetic merit, significantly decreased the 20-year HORNED allele frequency (30%), but resulted in a significantly slower rate of genetic gain ($6.70/year, P ≤ 0.05). The mating scheme that required the exclusive use of homozygous polled bulls, resulted in the lowest 20-year HORNED allele frequency (8%), but this conventional breeding scenario resulted in the slowest rate of genetic gain ($5.50/year). The addition of gene editing the top 1% or 10% of seedstock bull calves/year to each conventional breeding scenario resulted in significantly faster rates of genetic gain (up to $8.10/year, P ≤ 0.05). Overall, our study demonstrates that, due to the limited number of polled Australian Brahman bulls, strong selection pressure on polled will be necessary to meaningfully increase the number of polled animals in this population. Moreover, these scenarios illustrate how gene editing could be a tool for accelerating the development of high-genetic-merit homozygous polled sires to mitigate the current trade-off of slower genetic gain associated with decreasing HORNED allele frequency in the Australian Brahman population.

Integrating Philosophy of Science into Research on Ethical, Legal and Social Issues in the Life Sciences

This paper argues that research on normative issues in the life sciences will benefit from a tighter integration of philosophy of science. We examine research on ethical, legal and social issues in the life sciences (“ELSI”) and discuss three illustrative examples of normative issues that arise in different areas of the life sciences. These examples show that important normative questions are highly dependent on epistemic issues which so far have not been addressed sufficiently in ELSI, RRI and related areas of research. Accordingly, we argue for the integration of research on the epistemic aspects of the relevant areas of science into ELSI research to provide a better basis for addressing normative questions.

Harnessing endogenous repair mechanisms for targeted gene knock-in of bovine embryos

Introducing useful traits into livestock breeding programs through gene knock-ins has proven challenging. Typically, targeted insertions have been performed in cell lines, followed by somatic cell nuclear transfer cloning, which can be inefficient. An alternative is to introduce genome editing reagents and a homologous recombination (HR) donor template into embryos to trigger homology directed repair (HDR). However, the HR pathway is primarily restricted to actively dividing cells (S/G2-phase) and its efficiency for the introduction of large DNA sequences in zygotes is low. The homology-mediated end joining (HMEJ) approach has been shown to improve knock-in efficiency in non-dividing cells and to harness HDR after direct injection of embryos. The knock-in efficiency for a 1.8 kb gene was contrasted when combining microinjection of a gRNA/Cas9 ribonucleoprotein complex with a traditional HR donor template or an HMEJ template in bovine zygotes. The HMEJ template resulted in a significantly higher rate of gene knock-in as compared to the HR template (37.0% and 13.8%; P < 0.05). Additionally, more than a third of the knock-in embryos (36.9%) were non-mosaic. This approach will facilitate the one-step introduction of gene constructs at a specific location of the bovine genome and contribute to the next generation of elite cattle.

Genetic switches designed for eukaryotic cells and controlled by serine integrases

Recently, new serine integrases have been identified, increasing the possibility of scaling up genomic modulation tools. Here, we describe the use of unidirectional genetic switches to evaluate the functionality of six serine integrases in different eukaryotic systems: the HEK 293T cell lineage, bovine fibroblasts and plant protoplasts. Moreover, integrase activity was also tested in human cell types of therapeutic interest: peripheral blood mononuclear cells (PBMCs), neural stem cells (NSCs) and undifferentiated embryonic stem (ES) cells. The switches were composed of plasmids designed to flip two different genetic parts driven by serine integrases. Cell-based assays were evaluated by measurement of EGFP fluorescence and by molecular analysis of attL/attR sites formation after integrase functionality. Our results demonstrate that all the integrases were capable of inverting the targeted DNA sequences, exhibiting distinct performances based on the cell type or the switchable genetic sequence. These results should support the development of tunable genetic circuits to regulate eukaryotic gene expression.

The coding loci of evolution and domestication: current knowledge and implications for bio-inspired genome editing

One promising application of CRISPR/Cas9 is to create targeted mutations to introduce traits of interest into domesticated organisms. However, a major current limitation for crop and livestock improvement is to identify the precise genes and genetic changes that must be engineered to obtain traits of interest. Here, we discuss the advantages of bio-inspired genome editing, i.e. the engineered introduction of natural mutations that have already been associated with traits of interest in other lineages (breeds, populations or species). To obtain a landscape view of potential targets for genome editing, we used Gephebase (www.gephebase.org), a manually curated database compiling published data about the genes responsible for evolutionary and domesticated changes across eukaryotes, and examined the &gt;1200 mutations that have been identified in the coding regions of more than 700 genes in animals, plants and yeasts. We observe that our genetic knowledge is relatively important for certain traits, such as xenobiotic resistance, and poor for others. We also note that protein-null alleles, often owing to nonsense and frameshift mutations, represent a large fraction of the known loci of domestication (42% of identified coding mutations), compared with intraspecific (27%) and interspecific evolution (11%). Although this trend may be subject to detection, publication and curation biases, it is consistent with the idea that breeders have selected large-effect mutations underlying adaptive traits in specific settings, but that these mutations and associated phenotypes would not survive the vagaries of changing external and internal environments. Our compilation of the loci of evolution and domestication uncovers interesting options for bio-inspired and transgene-free genome editing.

Global developments of genome editing in agriculture

Genome editing, particularly using of site-directed nucleases such as the CRISPR system, has spread rapidly through the biological sciences. Genome editing in crops could significantly speed up the progress of breeding programs. It could drive the development of traits in new crops and allow improvements in yield and pest resistance, adaptation to climate change, and industrial and pharmaceutical applications. However biofortification is a key challenge to satisfy nutritional needs in vitamins for developing countries and new consumer's needs for developed countries. China and the USA lead scientific research in crop editing. Nigeria, being headquarters to numerous research consortia, is the most involved country in Africa. Genome editing in animals including pig, cattle, sheep, and carp, has not merely accelerated research but has made possible research that was previously unfeasible. It has been used to increase disease resistance, to make livestock better adapted to farming or environmental conditions, to increase fertility and growth, and to improve animal welfare. The USA, the UK and China are the most involved countries in animal genome editing. Global food production needs to increase as much as 70 per cent to support the growing population. Genome editing could contribute improving the efficiency of food distribution and reducing waste. Depending on the regulatory conditions, genome editing could open up the field to smaller companies and public labs.

Application of genome editing in farm animals: cattle

Milk and meat from cattle and buffaloes contribute 45% of the global animal protein supply, followed by chickens (31%), and pigs (20%). In 2016, the global cattle population of 1.0 billion head produced 6.5 billion tons of cows' milk, and 66 million tons of beef. In the past century, cattle breeding programs have greatly increased the yield per animal with a resultant decrease in the emissions intensity per unit of milk or beef, but this has not been true in all regions. Genome editing research in cattle to date has focused on disease resistance (e.g. tuberculosis), production (e.g. myostatin knockout; production of all-male offspring), elimination of allergens (e.g. beta-lactoglobulin knockout) and welfare (e.g. polled or hornlessness) traits. Modeling has revealed how the use of genome editing to introduce beneficial alleles into cattle breeds could maintain or even accelerate the rate of genetic gain accomplished by conventional breeding programs, and is a superior approach to the lengthy process of introgressing those same alleles from distant breeds. Genome editing could be used to precisely introduce useful alleles (e.g. heat tolerance, disease resistance) and haplotypes into native locally-adapted cattle breeds, thereby helping to improve their productivity. As with earlier genetic engineering approaches, whether breeders will be able to employ genome editing in cattle genetic improvement programs will very much depend upon global decisions around the regulatory framework and governance of genome editing for food animals.

Public attitudes toward genetic modification in dairy cattle

Genetic modification has been used to create dairy cattle without horns and with increased resistance to disease; applications that could be beneficial for animal welfare, farm profits, and worker safety. Our aim was to assess how different stated purposes were associated with public attitudes toward these two applications using a mixed methods approach. Using an online survey, U.S. participants were randomly assigned to one of ten treatments in a 2 (application: hornless or disease-resistant) x 5 (purposes: improved animal welfare, reduced costs, increased worker safety, all three purposes, or no purpose) factorial design. Each participant was asked to read a short description of the assigned treatment (e.g. hornlessness to improve calf welfare) and then respond to a series of questions designed to assess attitude toward the treatment using 7-point Likert scales (1 = most negative; 7 = most positive). Responses of 957 participants were averaged to creative an attitude construct score. Participants were also asked to explain their response to the treatment. Qualitative analysis of these text responses was used to identify themes associated with the participants’ reasoning. Participant attitudes were more favorable to disease resistance than to hornlessness (mean ± SE attitude score: 4.5 ± 0.15 vs. 3.7 ± 0.14). In the ‘disease-resistance’ group participants had more positive attitudes toward genetic modification when the described purpose was animal welfare versus reduction of costs (contrast = 1.00; 95% CI = 0.12–1.88). Attitudes were less favorable to the ‘hornless’ application if no purpose was provided versus when the stated purpose was either to improve animal welfare (contrast = 0.95; 95% CI = 0.26–1.64) or when all purposes were provided (contrast = 0.88; 95% CI = 0.19–1.58). Similarly, attitudes were less positive when the stated purpose was to reduce costs versus either improving animal welfare (contrast = 0.86; 95% CI = 0.09–1.64) or when all purposes were provided (contrast = 0.79; 95% CI = 0.02–1.56). Quantitative and qualitative analysis indicated that both the specific application and perceived purpose (particularly when related to animal welfare) can affect public attitudes toward genetic modification.

A Population Genomics Analysis of the Native Irish Galway Sheep Breed

The Galway sheep population is the only native Irish sheep breed and this livestock genetic resource is currently categorised as 'at-risk'. In the present study, comparative population genomics analyses of Galway sheep and other sheep populations of European origin were used to investigate the microevolution and recent genetic history of the breed. These analyses support the hypothesis that British Leicester sheep were used in the formation of the Galway. When compared to conventional and endangered breeds, the Galway breed was intermediate in effective population size, genomic inbreeding and runs of homozygosity. This indicates that, although the Galway breed is declining, it is still relatively genetically diverse and that conservation and management plans informed by genomic information may aid its recovery. The Galway breed also exhibited distinct genomic signatures of artificial or natural selection when compared to other breeds, which highlighted candidate genes that may be involved in production and health traits.

Potential of Genome Editing to Improve Aquaculture Breeding and Production

Aquaculture is the fastest growing food production sector and is rapidly becoming the primary source of seafood for human diets. Selective breeding programs are enabling genetic improvement of production traits, such as disease resistance, but progress is limited by the heritability of the trait and generation interval of the species. New breeding technologies, such as genome editing using CRISPR/Cas9 have the potential to expedite sustainable genetic improvement in aquaculture. Genome editing can rapidly introduce favorable changes to the genome, such as fixing alleles at existing trait loci, creating de novo alleles, or introducing alleles from other strains or species. The high fecundity and external fertilization of most aquaculture species can facilitate genome editing for research and application at a scale that is not possible in farmed terrestrial animals.

Proposed U.S. regulation of gene-edited food animals is not fit for purpose

Dietary DNA is generally regarded as safe to consume, and is a routine ingredient of food obtained from any living organism. Millions of naturally-occurring DNA variations are observed when comparing the genomic sequence of any two healthy individuals of a given species. Breeders routinely select desired traits resulting from this DNA variation to develop new cultivars and varieties of food plants and animals. Regulatory agencies do not evaluate these new varieties prior to commercial release. Gene editing tools now allow plant and animal breeders to precisely introduce useful genetic variation into agricultural breeding programs. The U.S. Department of Agriculture (USDA) announced that it has no plans to place additional regulations on gene-edited plants that could otherwise have been developed through traditional breeding prior to commercialization. However, the U.S. Food and Drug Administration (FDA) has proposed mandatory premarket new animal drug regulatory evaluation for all food animals whose genomes have been intentionally altered using modern molecular technologies including gene editing technologies. This runs counter to U.S. biotechnology policy that regulatory oversight should be triggered by unreasonable risk, and not by the fact that an organism has been modified by a particular process or technique. Breeder intention is not associated with product risk. Harmonizing the regulations associated with gene editing in food species is imperative to allow both plant and animal breeders access to gene editing tools to introduce useful sustainability traits like disease resistance, climate adaptability, and food quality attributes into U.S. agricultural breeding programs.

The antioxidant components of milk and their role in processing, ripening, and storage: Functional food

The current rate of population growth is so fast that, to feed this massive population, a 2-fold increase in land is required for the production of quality food. Improved dietary products such as milk and its products with antioxidant properties and functional foods of animal origin have been utilized to prevent chronic diseases. The designer milk contains low fat and less lactose, more protein, modified level of fatty acids, and desired amino acid profiles. The importance of milk and its products is due to the presence of protein, bioactive peptides, conjugated linoleic acid, omega-3 fatty acid, Vitamin D, selenium, and calcium. These constituents are present in milk product, play a key role in the physiological activities in human bodies, and act as anti-inflammatory, anti-tumor, antioxidant, hypocholesterolemic, immune boosting, and antimicrobial activities. Consumer awareness regarding benefits of designer foods such as milk and its products is almost non-existent worldwide and needs to be established to reach the benefits of designer food technologies in the near future. The main objective of this review was to collect data on the antioxidant properties of milk and its constituents which keep milk-derived products safe and preserved.

Screening of Streptococcus Suis serotype 2 resistance genes with GWAS and transcriptomic microarray analysis

BACKGROUND

Swine streptococcosis has caused great economic loss in the swine industry, and the major pathogen responsible for this disease is Streptococcus Suis serotype 2 (SS2). Disease resistance breeding is a fundamental way of resolving this problem. With the development of GWAS and transcriptomic microarray technology, we now have powerful research tools to identify SS2 resistance genes.

RESULTS

In this research, we generated an F₂ generation of SS2 resistant C57BL/6 and SS2 susceptive A/J mice. With the F₂ generation of these two mice strains and GWAS analysis, we identified 286 significant mouse genome SNPs sites associated with the SS2 resistance trait. Gene expression profiles for C57BL/6 and A/J were analyzed under SS2 infection pressure by microarray. In total, 251 differentially expressed genes were identified between these two mouse strains during SS2 infection. After combining the GWAS and gene expression profile data, we located two genes that were significantly associated with SS2 resistance, which were the UBA domain containing 1 gene (Ubac1) and Epsin 1 gene (Epn 1). GO classification and over-representation analysis revealed nine up-regulated related to immune function, which could potentially be involved in the C57BL/6 SS2 resistance trait.

CONCLUSION

This is the first study to use both SNP chip and gene express profile chip for SS2 resistance gene identification in mouse, and these results will contribute to swine SS2 resistance breeding.

Invited review: Reproductive and genomic technologies to optimize breeding strategies for genetic progress in dairy cattle

Abstract. Dairy cattle breeders have exploited technological advances that have emerged in the past in regards to reproduction and genomics. The implementation of such technologies in routine breeding programs has permitted genetic gains in traditional milk production traits as well as, more recently, in low-heritability traits like health and fertility. As demand for dairy products increases, it is important for dairy breeders to optimize the use of available technologies and to consider the many emerging technologies that are currently being investigated in various fields. Here we review a number of technologies that have helped shape dairy breeding programs in the past and present, along with those potentially forthcoming. These tools have materialized in the areas of reproduction, genotyping and sequencing, genetic modification, and epigenetics. Although many of these technologies bring encouraging opportunities for genetic improvement of dairy cattle populations, their applications and benefits need to be weighed with their impacts on economics, genetic diversity, and society.

Advances in genome editing for improved animal breeding: A review

Since centuries, the traits for production and disease resistance are being targeted while improving the genetic merit of domestic animals, using conventional breeding programs such as inbreeding, outbreeding, or introduction of marker-assisted selection. The arrival of new scientific concepts, such as cloning and genome engineering, has added a new and promising research dimension to the existing animal breeding programs. Development of genome editing technologies such as transcription activator-like effector nuclease, zinc finger nuclease, and clustered regularly interspaced short palindromic repeats systems begun a fresh era of genome editing, through which any change in the genome, including specific DNA sequence or indels, can be made with unprecedented precision and specificity. Furthermore, it offers an opportunity of intensification in the frequency of desirable alleles in an animal population through gene-edited individuals more rapidly than conventional breeding. The specific research is evolving swiftly with a focus on improvement of economically important animal species or their traits all of which form an important subject of this review. It also discusses the hurdles to commercialization of these techniques despite several patent applications owing to the ambiguous legal status of genome-editing methods on account of their disputed classification. Nonetheless, barring ethical concerns gene-editing entailing economically important genes offers a tremendous potential for breeding animals with desirable traits.

Engineering Quantitative Trait Variation for Crop Improvement by Genome Editing

Major advances in crop yields are needed in the coming decades. However, plant breeding is currently limited by incremental improvements in quantitative traits that often rely on laborious selection of rare naturally occurring mutations in gene-regulatory regions. Here, we demonstrate that CRISPR/Cas9 genome editing of promoters generates diverse cis-regulatory alleles that provide beneficial quantitative variation for breeding. We devised a simple genetic scheme, which exploits trans-generational heritability of Cas9 activity in heterozygous loss-of-function mutant backgrounds, to rapidly evaluate the phenotypic impact of numerous promoter variants for genes regulating three major productivity traits in tomato: fruit size, inflorescence branching, and plant architecture. Our approach allows immediate selection and fixation of novel alleles in transgene-free plants and fine manipulation of yield components. Beyond a platform to enhance variation for diverse agricultural traits, our findings provide a foundation for dissecting complex relationships between gene-regulatory changes and control of quantitative traits.

Genome edited animals: Learning from GM crops?

Genome editing of livestock is poised to become commercial reality, yet questions remain as to appropriate regulation, potential impact on the industry sector and public acceptability of products. This paper looks at how genome editing of livestock has attempted to learn some of the lessons from commercialisation of GM crops, and takes a systemic approach to explore some of the complexity and ambiguity in incorporating genome edited animals in a food production system. Current applications of genome editing are considered, viewed from the perspective of past technological applications. The question of what is genome editing, and can it be considered natural is examined. The implications of regulation on development of different sectors of livestock production systems are studied, with a particular focus on the veterinary sector. From an EU perspective, regulation of genome edited animals, although not necessarily the same as for GM crops, is advocated from a number of different perspectives. This paper aims to open up new avenues of research on genome edited animals, extending from the current primary focus on science and regulation, to engage with a wider-range of food system actors.