Gene editing, which has grown fast in the field of genetic technology, raises ethical questions. Is gene editing any more legitimate than any other method previously used to edit animal genomes? The issue prompted consideration by Penny Hawkins, head of the Animals in Science section of the British Royal Society for the Prevention of Cruelty to Animals. Hawkins was speaking at a Animal Welfare and Selective Breeding seminar organized by the Animal Welfare Ombudsman and the Finnish Centre for Animal Welfare at the end of May. Hawkins thinks gene editing is proceeding at such an action-packed pace that public understanding cannot keep up with it. She also raised concerns about gene editing techniques trickling out of laboratories all the way to farm animals and pets.
Use of gene scissors brings precision to modifying animal genomes, raises ethical issues
The genome of animals, plants and microbes can change in nature through unforeseen spontaneous mutations. Spontaneous mutation can lead to traits beneficial to the survival of the species, but also disease and health-degrading characteristics.
In mice, for example, there is a spontaneous mutation that leads to insufficient production of the dystrophin protein, which is important for the normal functioning of muscles. This condition called Duchenne muscular dystrophy also occurs in humans. In mice, however, Duchenne muscular dystrophy is not as pronounced as in humans and the discovery of a spontaneous mutation that causes muscular dystrophy led to the use of mice as a scientific model for the disease so that the disease can be studied.
Spontaneous mutations occurring in nature are unpredictable and slow. Human paces mutations through gene editing. The field of gene editing has come a long way from relatively inaccurate genome editing methods in the last decade to CRISP-CAS-9, commonly known as gene scissors, which has revolutionised the field and is cited as one of the biggest scientific breakthroughs of the 21st century. Unlike before, in the CRISP-CAS-9 technique, DNA can be modified exactly at the desired point in the genome. Gene scissors have revolutionized medical research and caused an explosive increase in gene editing in animals. The use of gene scissors improves accuracy in editing the animal’s genome. Despite its accuracy, genetic scissor technology raises ethical issues.
Gene editing briefly:
The genome of a microbe, animal, or plant is consciously altered, either by spurring a natural mutation or by modifying, removing or inserting a strand of DNA in a way that does not occur through natural mutation.
Laboratory animals are used as models for human and animal diseases and for understanding the function of individual genes. Among laboratory animals, the most genetically engineered animals are zebrafish and mice. Procedures that gene editing requires can be painful, especially for female mammas. In order to be able to edit mammalian genes, females’ eggs need to be collected.
The 3R principle protects against the unnecessary use of laboratory animals
In addition to the law, actions against laboratory animals in the EU and Norway are guided by the principles of 3R — replacement, reduction and refinement; experiments should use animal-free methods where possible, as few animals as possible, and test arrangements must be arranged to inflict minimal pain and suffering on the animal concerned. Methods that replace animal testing are constantly being developed, for example, utilizing cell culture, but progress is not yet reflected in the number of laboratory animals used.
If the transformative method of gene scissors has caused an explosive increase in animal gene editing, it is appropriate to ask whether the discovery of a new technique is sufficient justification for the use of animals?
Consideration of the welfare of animals used in experiments is a prerequisite for reliable research
Although genetically modified animals can serve as a good and more accurate model in medicine, animal testing settings are complicated for the welfare of laboratory animals. Laboratory animals spend most of their time outside experiments, in cages where the number of stimuli and the possibility for species-specific behaviour is limited.
Research suggests that as a result of an unstimulating environment, laboratory animals’ mental state and brain chemistry deviates from normal. An animal can be frustrated, depressed and apathetic when it cannot get to fulfil its species-specific behavioural needs. Hawkins mentions that this may also have an impact on the quality and reliability of research. When a laboratory animal acts as a model, for example, for the functioning of the human mind it can be difficult to assess whether the change in animal behaviour is due to the environment or genes.
In general, biological organisms are associated with the problem of characteristical differences between species and even individuals; even if a particular laboratory animal is considered to serve as the best possible model for humans, only minority of the drugs tested and found to be functional in animals are suitable for humans.
Gene scissor trickling out of laboratories causes concern
What Hawkins finds worrying, in particular, is that the use of gene scissors is trickling out of laboratories. Laboratory animals used for research purposes are protected by EU directives and country-specific regulations, as well as individually obtained permits for projects and people dealing with animals. The use of gene scissors in farmed animals could lead to the production of larger animals and increased yields of farmed animals.
Gene scissor technology is also covered by intellectual property rights, which guarantees exclusive business rights related to industrial activities. In the EU, genetic modification of animals for commercial breeding purposes is prohibited. With Brexit, regulation will not reach Great Britain, which has decided to loosen its regulations on gene-edited plants and possibly animals intended for food.
Gene scissors should not be used at the expense of animal welfare
The use of gene scissors can contribute to animal welfare, for example, in the form of better immune defences, or through the breeding of hornless cattle. Hornless cattle would not have to go through the painful disbudding that causes the animal to have a burn on the head. Disbudding is used because, in tight barn conditions, horns can be a safety hazard to both stockpersons and other animals.
Hawkins thinks using gene scissors is yet another way to modify an animal, and possibly more so. She recalls that the animal should not be processed to fit the environment; instead, the environment should be built to suit the animal. Hawkins underlines that the gene scissor method that revolutionized gene modification in animal breeding should not be used at the expense of animal welfare.
In the eyes of the law, animals are silent actors; they are subject to regulations that cannot be influenced by themselves and thus someone must do it for them. As an ending anecdote, Hawkins asks who has the power to decide which way to shape the genomes of animals and whether there is public understanding and general consent for gene editing in animals.
Hawkins was a keynote speaker at the seminar on Animal Welfare and Selective Breeding 23.-24.5.2022 in Helsinki, Finland. The seminar was organized by the Animal Welfare Ombudsman and the Finnish Centre for Animal Welfare FCAW.
Read more:
BBC, 2021. Rules to create gene-edited farm animals must put welfare first – a review.
See also:
Welfare of laboratory animals, Animal welfare in Finland 2022 (in Finnish)