Natural breeding more dangerous than genetic engineering

3 March 2008

OK, that title is slightly mischievous. When I say natural breeding, we’re not talking normal hot plant sex here, but something even hotter: bombarding the hapless veggies with gamma radiation to induce mutations.

It might not sound very natural to you and I, but according to regulators around the world, this counts as natural compared with genetic modification. If you induce a change by genetic engineering, you have to prove it’s safe. Do it by mutagenesis and no one cares.

Except a team in Portugal are now claiming that mutatagenesis results in more changes in gene expression (which genes are turned on or off) than genetic engineering. For greater changes read more potential to produce (more) toxic substances. After all, plants are primed to produce toxins to deter those that want to eat them.

In fact, history shows that even old-fashioned conventional breeding can be dangerous. The Lenape potato bred in the 1960s turned out to have dangerously high levels of solanine, the toxin found in all potatoes. The Magnum Bonum, an century-old breed from England reintroduced into Sweden in the 1990s, was similarly toxic. (“Old”; “traditional”; “natural”: gotta be good, hmm?)

The kiwi fruit bred in New Zealand from an inedible (but not toxic) Chinese berry and introduced to the US in the 1960s never underwent safety testing and caused allergic reactions in some people (recently shown to be due to a protein called actinidin). Hybrids between ordinary potatoes and related species have been found to produce a novel toxin not found in either parent called demissidine.

The list could go on and on. My point is not that genetic modification is wonderful but that we should be wary of everything we eat, however it was bred or created.


A cure for the common cold

7 December 2007

The last couple of weeks have been miserable at times. My son got a particularly nasty cold, which he passed on to me (I’m sure you get a megadose of virus from babies) and which seems to last for a fortnight.

“The common cold”, of course, is really a description of a particular set of symptoms. These can be caused by some very different viruses, some of which have been identified only in the past few years. There are undoubtedly others which have yet to be identified.

The diversity of these viruses, and the ability of some of them to mutate so fast they can repeatedly evade our immune system, means there’s never going to be a single effective treatment or vaccine against the common cold anytime soon. And with so many more hosts for them to mutate in than ever before – six billion and counting – I do worry that more nasty strains will emerge than before.

I’ve sometimes wondered if there is a simple way to eliminate the common cold.

Imagine if we planned an Global Cold Elimination Fortnight or Month. Basically, everyone who could stay at home would have to stay at home for at least a couple of weeks. All non-essential flights, trains, cars, bicycles and pedestrians would be halted. Those who absolutely had to go in to work, at power stations or hospitals, say, would wear biosafety suits and undergo screening if rapid tests become available, or both. At the end of the period, rigorous measures would be put in place to identify any outbreaks and contain them.

Done properly, it could eliminate many if not all of the dozens of cold viruses circulating in the population. Of course, in time new cold-like viruses would appear as animal viruses jumped into humans, but this will happen anyway and could prevented by a swift and effective reaction. Think SARS. It might eliminate many other viruses as well, from the vomit and diarrhoea-fest that is Norfolk virus to flu strains (although flu is so common in birds it will inevitably jump back into humans).

Now of course I realise this is never going to happen, in our lifetimes at least. Too many parts of the world are in too much chaos for this to be organised even if the agreement and will was there. And the agreement would never be forthcoming. The waaa-why-can’t-I-want-to-do-whatever-I-want-to-do-and-fuck-everyone-else brigade would declare it a federalist plot by Washington and Brussels, as they do any attempt to coordinate a global response to common threats such as climate change. The imams would declare it a plot against Islam. The capitalists would call it a communist plot… you get the picture.

But it does make sense economically. I haven’t been able to find any reliable figures for days lost to colds per year per worker, but some put it as high as 7 sick days a year. Even if you assume the average is just two, stopping the world for a couple of weeks would pay for itself in just five years. OK, everyone staying home at the same time isn’t the same as sick days spread among the population and in time, but the figures are probably in the same ball park.

Baby geniuses?

23 November 2007

This is what the researchers claim to have shown

Here we show that 6- and 10-month-old infants take into account an individual’s actions towards others in evaluating that individual as appealing or aversive: infants prefer an individual who helps another to one who hinders another

What they actually did was show babies a kind of puppet show and get them to pick a triangle or a square afterwards (apparently they varied the symbol/colour to rule out any effect from appearance alone but I haven’t checked the methods section myself). Call me sceptical, but I’m not convinced that picking a square or a triangle equates to preferring an “individual”.

I’d like to believe it’s true. But watching my own child hasn’t convinced me that such young children are capable of such sophistication. And while it’s undoubted true, as the researchers point out, that all social animals benefit from the ability to distinguish friend from foe, does it really help six-month-old babies?

I’m reserving judgement until the studies are repeated with humans rather than wooden symbols.

Reprogrammed skin cells

21 November 2007

Curious timing, isn’t it. On the weekend, Dolly creator Ian Wilmut announces he is abandoning cloning for reprogramming to create embryonic stem cells. On Tuesday, two teams announce that they have created ESC-like cells from human skin cells by adding various combinations of genes. 

So was Telegraph journalist Roger Highfield trying to beat the competition by running a related story? Or was Ian Wilmut attempting to steal his colleagues’ thunder ahead of the real event? (It worked. British TV news covered the Wilmut story but devoted little time to the latest news.)

I have to say that the thing that makes me least excited about the new method of creating ESC-like cells is that Wilmut is turning his attention to it. There are some brilliant scientists who never get lucky. There are some very poor scientists who get very lucky. I have no doubt which category Wilmut falls in.

Personalities (or the lack thereof) aside, I’m still can’t get very excited about a technique that generates cells that turn into teratomas when injected into mice. (Teratomas are very nasty cancers containing a mixture of cell types, sometimes even teeth.)

Regardless of whether you get them from cloning or reprogramming, cells with ESC properties are potentially very dangerous. My view is that the only way to make them safe will be to engineer a suicide gene that can be triggered, say, by a certain antibiotic. Having to trigger the switch will, of course, be a major bummer if you spent years recuperating from a stroke thanks to stem cells injected into the brain, only for them all to have to be destroyed. Still, it’s a risk worth taking.

The really interesting question is who will get the chance to take it. The success rate of the reprogramming techniques is pretty low and even if it can be dramatically improved, and made safe, it’s not going to become cheap anytime soon. Even in the unlikely event that any treatments based on this hit the clinic within a decade or so, it is likely to remain a (very) rich person’s treatment for some decades to come. That is, after it has been tested on poor people, of course. That will pose serious issues for public health systems like the UK’s.