A new threat to animals – the CRISPR GM technique
A new way of producing genetically modified animals could lead to increase in animal tests
- In a particularly cruel experiment on monkeys in China, researchers wanted to determine the function of a gene thought to play a significant role in ageing. This gene was ‘knocked-out’ of GM monkeys using CRISPR. To generate these monkeys, 48 embryos were transferred into 12 surrogate mothers, and of these, only 4 were successfully impregnated, with 3 completing their pregnancy and giving birth. Sadly, all 3 babies died soon after birth, and showed ‘retarded development’ that resembled that of a 2 to 4-month old foetus. Shockingly, the authors plan to continue to create these monkeys to study miscarriages and stillbirths (Ref. 8). We are writing to Nature to complain about their decision to publish this unethical study, which has little scientific merit.
- Scientists at the UK’s Royal Veterinary College have been breeding dogs with Duchenne muscular dystrophy (DMD), a rare and devastating muscle-wasting disease, in a bid to find a cure for the condition in humans. According to a journalist who visited the breeding facility, dogs with the disease were visibly weak and were seen stumbling and struggling to walk9. The scientists claim that they have managed to ‘cure’ DMD in dogs thanks to CRISPR, which they used to edit a mutated gene to once again produce dystrophin, an important muscle protein. Regardless of the hype, the study has already been widely criticised for several reasons including; its short duration (less than 2 months), the small number of dogs used (4 beagles), and uncertainty surrounding the long-term effects of the CRISPR, e.g. possibility that cancer-causing mutations may be introduced. Further, while the dogs were able to produce dystrophin, there was little evidence they regained any muscle function. Sadly, the researchers plan to conduct longer lasting experiments on a larger number of dogs (Ref. 10).
- UK Home Office. (2018). Statistics of Scientific Procedures on Living Animals: Great Britain 2017. [online] Available at: https://www.gov.uk/government/statistics/statistics-of-scientific-procedures-on-living-animals-great-britain-2017.
- LASA (Laboratory Animal Science Association). (2008). Position paper: transgenics. [online] Available: http://www.lasa.co.uk/PDF/position_transgenics.pdf
- BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement (2003). Refinement and reduction in the production of genetically modified mice. Laboratory Animals ;37 Suppl 1:S1-S49.
- Genome editing using CRISPR/Cas9-based knock-in approaches in zebrafish. (2017). Methods 121, 77-85.
- Ultra-superovulation for the CRISPR-Cas9-mediated production of gene-knockout, single-amino-acid-substituted, and floxed mice. (2016). Biology Open 5, 1142-1148.
- Refining strategies to translate genome editing to the clinic. (2017). Nature Medicine 23, 415-423.
- Opportunities and challenges in modeling human brain disorders in transgenic primates. (2016). Nature Neuroscience 19, 1123-1130.
- SIRT6 deficiency results in developmental retardation in cynomolgus monkeys. (2018). Nature, 560: 661-665.
- Beagles bred with muscular dystrophy offer ‘hope of a human cure’. (2015). The Guardian, 14 November: http://www.theguardian.com/science/2015/nov/15/beagles-study-hope-cure-muscular-dystrophy.
- In dogs, CRISPR fixes a muscular dystrophy. (2018). Science, 36(1): 835.
- Every silver lining has a cloud: the scientific and animal welfare issues surrounding a new approach to the production of transgenic animals. (2014). Alternatives to Laboratory Animals 42, 137-145.