Saturday, March 11, 2017

Matt Ridley: The possibilities opened up by gene editing


Scientists at the Roslin Institute, near Edinburgh, said last week that they had edited the genomes of pigs, rendering them immune to a dangerous virus. The announcement is extraordinary precisely because it sounds almost routine these days. 

Gene editing is already starting to save the lives of human cancer patients and generate healthier crops. Yet the battle to ensure it gains favour with public opinion must be urgently addressed. The usual suspects are already trying to blacken its name.

Pause first to admire the breathtaking ingenuity of modern biotechnology. Today we know the shape, structure and genetic code of the pig virus, we know which cells in the pig’s immune system it attacks and we know which pig gene encodes the protein on the cell surface that the virus uses to gain entry to the cell.

With the new gene-editing tool Crispr-Cas9, the Roslin scientists sliced out a short section from this gene in the fertilised egg of a pig. They then grew pigs from these eggs that turned out healthy and entirely normal in every way, including the functioning of the gene, but which denied the virus entry to the cell.

Crispr is the newest, fastest and most precise way to edit a genome yet invented, but it comes on the heels of others — Talens and zinc-finger nucleases among them — all just a few years old. A different technique, gene silencing by RNA interference, is also bearing fruit. This diverse toolkit now allows scientists to improve the genome with precise changes. 

Cue an outbreak of horror about the risks of (cliché alert) designer babies. One newspaper has been blathering about “Frankenstein pigs”. But a similar technique is already being used to treat leukaemia in children: are they Frankenstein kids? Cellectis, a French company, is using Talens to remove the small section of DNA that causes cells from donors to attack recipients. These donor cells are then used to treat the children with cancer and appear, in early trials, to be saving lives.

What will be the public reaction to the release of gene-edited animals or plants? Bring it on and cure us, or how dare you try to poison us? We have been here before, twice. In the 1970s, “genetic engineering” came along: the idea of putting human genes into bacteria and thereby mass-producing medicines for conditions such as diabetes and haemophilia. A few worried cities banned the technique briefly, but it is now universally available, even in Catholic countries, and saves thousands of lives every day without a peep of protest.

In the 1990s, “genetic modification” of plants arrived: putting genes from other species into crops to make them insect resistant, herbicide resistant, or healthier. Europe reacted with horror and, though the technique rapidly caught on in the Americas and parts of Asia and proved good for the environment, a rearguard action by environmentalists has gradually tied down such genetically modified organisms (GMOs) in regulatory red tape and lucrative (for activists) political feuds.

Gene editing in crops is the next such battle. There are three reasons to think it is bound to be safer than anything that went before. First, gene editing comes after genetic engineering and modification proved wholly safe. There have been no unpleasant surprises. Second, it involves no “foreign” DNA. The big objection to GMOs, we were told, was that they “crossed the species barrier”, though Mother Nature does so at will, we now know. This doesn’t.

Third, the process is indistinguishable in outcome from much older techniques, such as cross breeding, that have never been regulated, yet it is far more precise. How many people are aware that hundreds — yes, hundreds — of organic — yes, organic — varieties of crops were generated by “mutagenesis”, the random scrambling of DNA by gamma rays or carcinogenic chemicals?

Stefan Jansson, from Umea University in Sweden, put it this way: “Common sense and scientific logic says that it is impossible to have two identical plants where growth of one is, in reality, forbidden while the other can be grown with no restrictions; how would a court be able to decide if the cultivation was a crime or not?”

Last April, the US Department of Agriculture declined to regulate a gene-edited mushroom and a gene-edited maize variety as if they were GMOs, arguing, sensibly, that there was no way to distinguish them from new varieties produced in an old-fashioned way. So America can press ahead with new soybeans with healthier omega-3 fatty acids in them, cattle that don’t have to have their horns removed, and herbicide-resistant oilseed rape that can be grown without ploughing.

Europeans, meanwhile, are stuck in permanent, pathetic indecision. As Nature magazine put it in an editorial last week, the EU is “habitually paralysed whenever genetic modification is discussed. Two years ago the European Commission requested all member states to hold back on giving the all-clear on gene editing while it considered its options. Now its hand is being forced, ever so slowly, by the referral of the issue by France to the European Court of Justice last October.” A decision is not expected before 2018.

Broadly speaking, and characteristically, the French are against the new technique, the Germans are split, while the Dutch and Swedes want to go ahead. The British government is saying nothing. This is pusillanimous. We are pioneers in the use of gene editing in research, even on human embryos, and on gene-editing therapy of the kind used in the leukaemia trials and the pig experiments. We have none of the Roman Catholic hang-ups that stop some European countries tampering with nature even when nature is cruel.


We should get out there and say: gene editing is the most exciting new tool in our kit. It promises ways of improving human and animal health and reducing the environmental impact of agriculture. The technique itself cannot be considered dangerous though, of course, regulation should prevent its use for products that are thought dangerous, just as we would with any other technique. And since the European Union has not made up its mind about gene editing in farming and will not for another year, we should boldly state publicly that we are clear to press ahead with approvals, and welcome further research here.

Matt Ridley, a member of the British House of Lords, is an acclaimed author who blogs at www.rationaloptimist.com

1 comment:

Peter Caulton said...

The sooner the EU goes the way of the dodo the better.