Radio Review: Editing Life

Professor Matthew Cobb, a biologist at the University of Manchester, investigates some of the implications of the groundbreaking CRISPR genome-editing technology in this 30-minute BBC Radio 4 documentary.

With the help of international researchers and academics, he highlights some of the arguments for and against allowing progress in this rapidly changing field of genetic research, in humans as well as the natural world. The documentary provides an excellent explanation of the science, and a balanced view on its implications.

CRISPR, has been a revolution in genome editing, allowing us to edit DNA at the level of single nucleotides – a level of precision we have never achieved before. The technology is 'easy, fast and fun', as described by Sheila Jasanoff, professor of science and technology studies at the Harvard Kennedy School.

And, as Professor Cobb explains, CRISPR is taking the world of biological research by storm. For the documentary, he asked fellow colleagues who work with CRISPR for their thoughts and contributions. Within an hour of doing so, he had received over ten emails – indicating the volume of work currently being done in the field.

Much of the media coverage on CRISPR so far has – understandably – focused on its potential use in eradicating genetic disorders in humans, and the associated ethical dilemmas. As a result, the word CRISPR has become almost inextricably tied up with tricky moral dilemmas.

The technology has the potential to lead to unintended consequences but also, if used to modify the germline, CRISPR would affect the genomes of subsequent offspring. Consequently, an international summit held in December 2015 reached an agreement that research involving CRISPR technology for human genome editing should be allowed to continue, but that any application in embryos or germline cells should be avoided – for the moment (see BioNews 831).

Emily Crossley, Director of the Duchenne Children's Trust, said she would welcome the use of CRISPR to correct what she called 'faulty' genes. She referred to CRISPR's potential as the 'holy grail' in the case of Duchenne muscular dystrophy, a rare and incurable disease that leads to muscle degeneration and premature death in boys. Her son has the condition, and Emily said it is 'unbearable' to watch him struggle to walk up stairs, to walk and to run.

But this programme also raised as many questions about CRISPR's implications for the natural world. And with the recent emergence of the Zika virus raising the possibility of using CRISPR, Professor Cobb's focus on how the technology could help is extremely timely.

He interviewed Dr Tony Nolan, a molecular biologist at Imperial College London, who is part of a team of researchers using CRISPR technology to create what is known as a 'gene drive'. This is an attempt to spread a genetic alteration throughout a species or population by forcing it to be passed on to subsequent offspring (as opposed to the 50/50 chance of that happening by nature).

In Dr Nolan's case, the goal is to genetically edit malaria-carrying mosquitos to make them sterile, release them back into the wider malaria-carrying mosquito population and spread infertility, eventually wiping them out entirely. But what are the risks? Could there be unintended consequences? Dr Nolan explains that risk assessments are being carried out to look at the ecological effects of such a strategy but that at present, no known predator relies on the malaria-carrying mosquito.

Whether that is reason enough to carry on with a gene drive may be a matter for ecologists. Professor Mike Bonsall from the Department of Zoology at the University of Oxford is concerned that 'we have not yet had full conversations about the broader environmental implications' of gene drives. If you remove something from the ecosystem, what will happen? What will replace it?

Professor Bonsall does concede however, that the problem with a moratorium on the use of CRISPR in such scenarios is that you have to be content to carry on 'letting' huge numbers of people – particularly children – die of malaria each year, when there could be a way to stop it.

Professor of Genetics at Harvard Medical School, George Church believes that international decision-making is key here. He says that, whether intentional or not, gene drives have the potential to cross international borders.

And Professor Cobb agrees. The focus of discussion about CRISPR has so far been on human genome editing, which is ethically challenging and potentially life-changing for millions of people around the world. However, he points out that CRISPR-modified life forms could be a much more far-reaching issue, and therefore requires international agreement about when it should be used, who should decide that, and how its effects should be monitored. 'Such an international framework will require scientific understanding on the part of the whole population – and “political will”. Right now, we’re a long way from there,' he concludes.