by Matthew Cobb
I’ve recently made a BBC radio programme about gene editing, a new form of genetic manipulation that generally goes by the name of the acronym CRISPR. Over the last 3-4 years this technique has taken biological and medical research by storm. Clinical trials of therapies for patients suffering blood-born genetic diseases may be only a couple of years away. Although the prospect of ‘designer babies’ excite ethicists and the media, I think a bigger issue is posed by the prospect of CRISPR-based ‘gene drives’.
Gene drives are techniques for spreading genes through a sexually-reproducing population, which can very quickly affect every organism. These are the approaches that some people are suggesting would be a way of stopping diseases transmitted by certain species of mosquito, by rendering all the mosquitoes sterile (and thereby making them disappear) or by altering them so that they cannot host the malaria parasite, or they cannot detect their human prey).
Clearly, things could go wrong, and we could find ourselves doing serious damage to the ecosystem. For the moment, there are no international regulations to control this kind of work, even though many of the scientists involved are keen to see such a framework.
In the radio programme, which only lasts 30 minutes, I explain how CRISPR works, talk to some of the people who developed CRISPR, and to those who are seeking to apply it, both in humans – there is a moving interview with the mother of a young boy with Duchenne’s Muscular Dystrophy, who founded a charity to support research – and in insects. The theme is the scientific, ethical and ecological implications of this amazing new technology.
The programme, which is called “Editing Life”, will be on BBC Radio 4 at 11:00 am UK time, tomorrow morning, Tuesday 9 February. There will also be an article in The Guardian, which I’ll link to tomorrow. In March there will be an extended version, consisting of two programmes, which will go out on the BBC World Service.
You can listen to the programme live here, from anywhere in the world. If you miss the programme, you can catch up with it here, again from anywhere in the world.
Thanks, Matthew. I look forward to listening to this. I’ve followed a bit about CRISPR ( Eric Lander at the Broad Institute and the woman at Berkeley whose name escapes me…)
Thanks for the info and links.
This question is probably stupid (sorry), is there a difference between gene therapy and gene editing?
Sure is. I’m no doctor, but we were talking about gene therapy in the 90s as being one of the promising avenues for an HIV cure. The idea in this instance (not that all gene therapy is the same) was to modify the way T-cells were being made in the body… from progenitor stem cells, which are determined to be different types mostly in key places in the body. The focus was on the sternum as a place where whole-scale modifications to the human genome could take place. By splicing in desired genes into key cells, the idea was that the body would continue to produce T-cells that were resistant to infection by HIV and which would eventually outnumber other T-cells getting taken out by the virus. Eventually, it was thought, all the cells in the body would turn over, leaving the patient HIV-free in 10-20 years or so. The short story here is that gene therapy involved splicing comparatively big hunks of DNA into the genome.
Gene editing, on the other hand, seems to be more akin to gene microsurgery. Like taking a typewriter and making slight edits in key places… substituting smaller sequences here and there for other ones. I’m learning the methods are sometimes similar (use of “nucleases” to target where to cut into existing DNA strands), but gene editing seems to be newer, more exacting methods of modifying a genome for whatever purpose, whereas gene therapy more commonly describes all manner of delivery of therapeutic nucleic acid agents to address disease. (above article mentions using viruses as a delivery system for gene therapy, for example).
Thank you, very much! I see the distinction now.
You’re very much welcome. On re-reading my explanation, it looks like I said “Sure is” in answer to your phrase: “This question is probably stupid.” I’m glad you used the principle of charity regarding my response. 🙂
No prob. Take care.
I believe 11AM would be about 5 AM. Chicago time.
I’ve set my Deranged Idiot to record it (I’ll be in a meeting at the time), and if necessary I’ll try to hack that into an MP£, if I can’t find it directly.
MP3, even.
MP$! 😉
It’s a radio programme!
Reblogged this on My Selfish Gene and commented:
If you haven’t yet heard of CRISPR you will. It’s a genome editing tool that has given genomic researchers the ability to edit genes with precision and efficiency only dreamed of just a few years ago. Using CRISPR, also called Cas9, researchers have excised the HIV-1 genome from an infected cell (cf here http://www.pnas.org/content/111/31/11461.abstract) and Chinese researchers have used the technique on non-viable human embryos. The technique holds great promise. I’ve recently written about the Zika outbreak in South and Central America (cf here) and CRISPR could be used to remove this virus from the mosquito vector or even to remove the ability for the mosquito to reproduce and thereby eradicating the insect. Is this ethical? Is it healthy for the ecosystem? Whatever promise CRISPR has there are just as many ethical questions for something so powerful. Designer babies may be a ways off but are certainly in view.
Matthew Cobb, professor, researcher, and writer by day, is also a stalwart on Jerry Coyne’s website Why Evolution is True. Per Coyne’s site, Cobb has done a radio broadcast with the BBC regarding the CRISPR tool. The program is called ‘Editing Life’ and can be heard live or later as a recording. Sounds like good stuff to me!
Texas too, if I’ve heard correctly.
I was trying to get some handle on the actual risks from Zika. From what I understand from the news, the microcephaly case count in Brazil has gone from O(300) (“order of 300″) to O(4000), so far, suggesting O(3700) cases of microcephaly consequent on Zika infection. So far, so uncontroversial.
But what’s the case count of Zika cases? If it’s O(10k), then it’s a sever threat. If it’s O(million), then it’s a significant side effect, but it’s not the end of civilisation.
Other than the risk of microcephaly, the disease is described as mild, which is unlikely to lead to an accurate case count.
For comparison, I wonder what the brain-damage effect rate for Scarlet Fever (Rubella) was. [Wikipedia]”In Japan, [over 2013] 15,000 cases of rubella and 43 cases of congenital rubella syndrome” About 1:350, just under 0.3%. Which is a rate worth doing something about, but not needing Chicken Little responses.
Are you epidemiologist? Only someone seeing populations as stats would put microcephaly and Chicken Little in the same sentence! I have read that Brazil reported 100k adult cases in 2015. But the stat that interests me is how many pregnant women or soon to be pregnant woman were exposed and how many carried babies to term and how many developed or evinced microcephaly. 4k out of a 100k is small. 4k out of 50k (half women) is getting serious. 4k out of 25k is truly a concern. I read a report today that Brazilian researchers found that Zika can be detected in saliva. Can it pass through kissing? Not enough known yet.
What really interests me in the church’s position. To my knowledge the RCC hasn’t made any public statement yet. What will they say other than abstain from sex? For how long? It will be interesting to see how this plays out.
Not an epidemiologist at all, though having spent most of the last couple of years working in and around West Africa, one does pay attention to the health situation, if only out of self preservation.
There are a lot of unknowns about Zika, but it has already been demonstrated to be sexually transmissible for some months after the patient becomes symptom-free. Another open question is whether the microcephaly is a consequence of foetal exposure to the virus, or of exposure to the antibodies (in which case, women who have had the disease in the past would be more prone to giving birth to microcephalic infants in the future. The mode of causation of the microcephaly is another interesting question.
But overall, it doesn’t seem to be a (locally) civilisation threatening disease. Unlike Ebola.
I think you mean “German Measles (Rubella)”. Scarlet fever is a childhood disease.
Doh! Oops.
Looking forward to the show. It’s been a while since I’ve done any chromosome slicing and dicing but the CRISPR tool and surrounding ethical issues area fascinating. Thanks for the heads up.
The ability to eliminate a species from the wild by gene editing is frightening. But I don’t understand how a self-destructive gene could spread faster than any ordinary deleterious or nearly neutral gene. I suppose you could create a “sleeper gene” that isn’t deleterious until some special event (like an extreme cold snap). But even this would not spread faster than a normal neutral gene, with very low probability of fixation. Am I missing something?
With gene drive you can make genes for which inheritance is non-mendelian, so the gene’s frequency increases even with no honest selective advantage. If the gene has the effect of making all offspring male (one example), then the fraction of the population that is female can go to zero and extinction occurs.
Yes, meiotically driven t alleles that cause sterility are thought to have driven mouse populations extinct–JAC
I have been hearing about CRISPR for a couple years now. My old post-doc mentor, Ethan Bier, has been using it in Drosophila), and he was interviewed on NPR a while back about it. I was very delighted to hear his voice coming over the radio while I drove down the highway.
There is a substantial dust-up over competing groups about who gets credit over key parts in the evolution this major new technology. At stake are whopping patent rights, a Nobel prize, etc. The sordid story is summarized in an article in the latest Scientific American.
By coincidence, I’m watching a programme about, amongst others, one of the most famous clinical cases of haemophilia – Tsarovich Alexei.
I would expect that this would be one of the high-priority targets (one of many, admittedly).
Great!
We were talking about gene editing last night at the Royal Institute’s Fiction Lab run by UCL scientist Dr. Jenny Rohn…
Thanks! Will be sure to listen when time allows.