Letter on the problems associated with CRISPR-mediated gene editing. Cruelty Fee INTERNATIONAL: Ending animal experiments worldwide.
Trends in Biotechnology has published a letter by Dr Jarrod Bailey, Senior Research Scientist at Cruelty Free International, which summarizes the many scientific and ethical issues with the use of clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genetic modification (GM) (Bailey, 2019).
The CRISPR technique is becoming an increasingly popular tool for gene editing because it is an inexpensive, relatively simple and quick way of producing GM animals. It has also been claimed to not only be more accurate than traditional methods but to actually help reduce animal numbers (because it is so accurate that fewer animals might be wasted). However, there remains substantial evidence to warrant great concern over the poor efficiency of CRISPR. In his Letter, Dr Bailey argues that there is evidence that the efficiency of CRISPR to "knock-in" a particular gene in an animal is less than 4%, while the efficiency to "knock-out" a gene is around 7%. Furthermore, it appears that CRISPR introduces unwanted or "off-target" mutations and while the degree is open to question, these unintended genetic modifications can have serious consequences for animal welfare and wastage.