Cutting Edge Technology
Erica Mannis looks at the 2020 Nobel prize winning discovery on gene editing using the CRISPR-Cas9 system and discusses potential ethical aspects of the discovery
CRISPR-Cas9 genetic technology has been at the forefront of scientific news in recent years for its breakthrough in genetic research. However, with its vast applications come worrying ethical dilemmas. Two women; Emmanuelle Charpentier and Jennifer Douda have won the 2020 Nobel Prize in Chemistry for their contribution to this ground-breaking research.
CRISPR is a genome editing tool which has huge potential to treat or prevent human diseases. It works by finding a specific section of DNA within a cell and editing it. Methods using CRISPR technology were first unveiled in 2012, however, they are now far cheaper and are becoming increasingly common; many people around the world already eat food that has been edited by CRISPR technology!
Cas proteins are found in bacteria and are used by them to kill viruses- destroying their DNA in the immune response. Using RNA guided endonucleases, bacteria cut the viral DNA integrated to their own genome. The spacing of viral section DNA in the bacteria’s genome is what CRISPR is named after: clustered regularly interspaced short palindromic repeats.
In the CRISPR system an RNA guide complementary binds to target genes and the cas-9 protein cuts this section of DNA. When bacteria are performing repair mechanisms, mutations can be introduced into the desired gene and extremely precise alterations of genes can be created via this method, however, this is difficult. There are also types of customised Cas proteins which have the ability to completely turn genes on or off.
In 2011 Charpentier identified the RNA section involved in recognising the viral phage sequence of the genome. In 2012 the pair then worked together to isolate and adapt parts of the system so that it would work in a test tube and cut specific sites of DNA.
Whilst this work is truly outstanding, with the possibility to prevent life threatening genetic disorders, there are many ethical concerns.
One of the greatest concerns is gene-edited babies. The concept of customising a baby’s genetics can lead to other enhancements beyond disease prevention (for example, prosthetics). In 2018 a Chinese scientist admitted to editing 2 human embryos to give them resistance to HIV, whilst there is little evidence of any other harm to the babies, the scientist did received a prison sentence for his lack of ethical considerations when performing these genetic alterations.
Other concerns include difficulties with DNA variants on a single gene and the possibility of it leading to unwanted changes to the genome. Better screening methods must be developed to check for these errors. A bit concern is that the long-term effects of this sort of gene editing is not known.
CRISPR technology has many applications in aspects such as; genetically edited foods, mutations for scientific research and in disease prevention. However, before it can become a widely used medical treatment, national and international evidence based legislation is required to prevent unethical and potentially life threatening use of gene editing technology. However, the recognition of the two female scientists for their work in developing this method is a crucial turning point in society- reducing the stigma surrounding women in STEM.
