h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I am getting really sick and tired of people moaning about how GM food is going to be the end of life on earth. Of how it's going to "infect" all other crops and poison everything, and how I am "full of s**t" for not believing them.

I am doing a BSc(hons) in Genetics! I'd hope that I know just a little more about the subject than your average person on the street!

*whew* That feels better

Then you'll be able to confirm that soil bacteria can pick up genes from their surroundings.

You may also be able to confirm that the British wild flower, Brassica napus, may cross-pollinate with its cultivated cousins of the same species, oilseed rape and the swedish turnip and that feral rape commonly grows in the verges in areas where rape is cultivated.

By the way, I have bought & eaten what I think were GM tomatoes without having or worrying about ill effects. The only downside is their bland taste. (So why are they called "Flava Sava"?? The name alone gets me going.)

Dry.

Yup, you're exactly right about the Oilseed Rape. Nice to have someone who actually knows a little about the subject

And yes, some bacteria can take up genes from their surroundings. Heck, some do it so much that you just need to stick some naked DNA in their environment and they'll suck it up like a vacuum cleaner! But in order for it to actually make a difference it needs to a) be taken up, b) be stably inheritable and c) be of adaptive advantage to the organism.

Some can take up DNA quite easily, but for them to be stably inherited they need to either be circular with an origin of replication (ie. a plasmid) or to insert into the bacterial chromosome - and this requires homology. And for adaptive advantage you need to have it expressed, which is very difficult to do with a plant gene in a bacterium. The promoter wouldn't work, the codon bias would be all wrong, and it's got all sorts of things like different ribosome recognition sites, etc..

Anyway, its important to remember that this can happen with _any_ gene, not just inserted ones. A bacterium can, theoretically, take up any DNA from its environment, and there is not really any reason why, for example, a fish gene that happens to be in a plant would be any more likely to be horizontally transferred than a fish gene that's in a fish, or a plant gene that's in a plant.

Ahh.. rants are fun

Did you know that the tobacco plant has been genetically modified to produce a caries vaccine?

It's great that a plant which has been responsible for so much damage to people's health can now be used to improve health.

Here in the states we have a group call science in the public intrest. and they have released the shocking news that chinese, mexicin, indian, food are bad for you, you are also not suppost to drink alcahol, smoke, have unprotected sex. or not where a seat belt and a helment while walking.
I beleve I have found the secret if we all don't eat anything and just hide under our bed, We well live forever.

Scaryfish: Sorry for the tardy reply. Many thanks for taking the time to explain that. So soil bacteria are unlikely vectors for the distribution of any genes. Is it true, as I remember hearing somewhere, that soil bacteria are used to introduce genes into plant chromosomes? How does that work, if plant (or, presumably, animal) genes cannot be replicated by the bacterial system?

I have an update on the feral rape plants. I had noticed they don't (usually) grow in the same place twice. The seeds are viable, as I've germinated them, but the pods just stay on the dead plant without dehiscing, so the seeds can't disperse. Presumably this is a trait introduced to aid harvesting and implies that the feral plants I've found must have grown from seeds dropped the previous season. There must be a steady supply of dropped seeds therefore.

Dry.

Take a look at this website:

http://www.netspeed.com.au/ttguy/default.htm

Thanks, Giskard. I haven't had such a good laugh for days. DNA free tomatoes indeed! Seriously, stuff like that is really bad news for those of us who think there may be serious scientific concerns about GM.

Some time ago I suggested that the farm-scale trials in Britain wouldn't solve the problem, as those in favour would play down any negative results and those against would do the reverse, which recent events promise to confirm. It's a fair bet that the modified genes from the GM rape trials have by now escaped into the native/feral Brassica napus population, but this is something the trials weren't designed to test.

I had come round to the idea that GM maize may not be such a bad idea after seeing a report comparing GM and non-GM maize in Spain, showing that the non-GM maize suffers really badly from a stem boring parasite, which is why they blast it with pesticides. An important consideration, from my point of view, is that maize has no near relatives in the UK flora, which is not the case with the Swedish turnips & oilseed rape. Another plus is that, as far as I know, maize isn't an important "organic" crop in Britain.

Dry.