Can we talk about GM crops?

[gavin]

Shill I post something now?!

http://precedings.nature.com/documents/4765/version/1

The human genome is composed of viral DNA: Viral homologues of the protein products cause Alzheimer's disease and others via autoimmune mechanisms.

Christopher J. Carter1

The human genome is composed of millions of fragmented contiguous viral DNA sequences, dating from the dawn of evolution and reflecting retroviral insertions over millions of years of coexistence. Herpes and other viral insertion points correspond to the locations of over 120 Alzheimer's disease susceptibility genes and to linkage hotspots. The greater the number of pathogen matches, the more important the gene. These DNA sequences are translated into short contiguous 5-12 amino acid stretches (vatches), identical in viruses and man, and in other pathogens implicated in Alzheimer's disease (Borrelia, Chlamydia, Helicobacter, C. Neoformans , P. Gingivalis). C. Neoformans, which has been associated with a rare but curable form of dementia, expresses the most number of hits to Alzheimer's disease proteins. Vatches are often immunogenic and antibodies to viral proteins may knock down their human counterparts or activate immune responses killing the cells containing their human homologues. This is supported by the presence of the complement membrane attack complex in Alzheimer's disease neurones and by the ability of tau antigens (homologous to pathogen proteins) to promote the formation of neurofibrillary tangles and Alzheimer's disease pathology in mice. Vatches may act as dummy ligands or decoy receptors and interfere with the interactome of their human counterparts. Alzheimer's disease is thus a "pathogenetic" disorder caused by pathogens but dependent on the genes that create these matching sequences. This scenario is relevant to many other, and perhaps most human disorders, given the massive genomic extent of viral coverage. The vatches in the human proteome, dictated by polymorphisms and mutations, may predict, from birth, the spectrum of pathogens that match our proteins and which pathogenetic disease we are likely to develop. These may all be preventable by vaccination, pathogen detection and elimination and curable by immunosuppressant approaches, perhaps with a unique, safe, and effective immunosuppressant panacea.

[Rosie]

How about this then. On subject as well!

Rosie

[gavin]

LOL! Pot-potatoes? We have the technology!

[Stromnessbees]

Shill I post something now?!

http://precedings.nature.com/documents/4765/version/1

The human genome is composed of viral DNA: Viral homologues of the protein products cause Alzheimer's disease and others via autoimmune mechanisms.

Christopher J. Carter1

The human genome is composed of millions of fragmented contiguous viral DNA sequences, dating from the dawn of evolution and reflecting retroviral insertions over millions of years of coexistence. Herpes and other viral insertion points correspond to the locations of over 120 Alzheimer's disease susceptibility genes and to linkage hotspots. The greater the number of pathogen matches, the more important the gene. These DNA sequences are translated into short contiguous 5-12 amino acid stretches (vatches), identical in viruses and man, and in other pathogens implicated in Alzheimer's disease (Borrelia, Chlamydia, Helicobacter, C. Neoformans , P. Gingivalis). C. Neoformans, which has been associated with a rare but curable form of dementia, expresses the most number of hits to Alzheimer's disease proteins. Vatches are often immunogenic and antibodies to viral proteins may knock down their human counterparts or activate immune responses killing the cells containing their human homologues. This is supported by the presence of the complement membrane attack complex in Alzheimer's disease neurones and by the ability of tau antigens (homologous to pathogen proteins) to promote the formation of neurofibrillary tangles and Alzheimer's disease pathology in mice. Vatches may act as dummy ligands or decoy receptors and interfere with the interactome of their human counterparts. Alzheimer's disease is thus a "pathogenetic" disorder caused by pathogens but dependent on the genes that create these matching sequences. This scenario is relevant to many other, and perhaps most human disorders, given the massive genomic extent of viral coverage. The vatches in the human proteome, dictated by polymorphisms and mutations, may predict, from birth, the spectrum of pathogens that match our proteins and which pathogenetic disease we are likely to develop. These may all be preventable by vaccination, pathogen detection and elimination and curable by immunosuppressant approaches, perhaps with a unique, safe, and effective immunosuppressant panacea.

Good job we have Gavin, who explains everything in easy to understand language and never tries to baffle us with science!

[beeanne]

But the article itself says the viral insertion took place over millenia. Not that it happened over the shortened period of GM. From my position of ignorance, is the DNA of virus' not relatively simple, and much simpler than of the DNA used in GM? Even if sometimes viral insertions were helpful, and sometimes indifferent, it does seem plausible that there's a decent risk of unintended consequences.
More importantly: it doesn't give me a warm glow that viral insertions into DNA are Good Things.... but this could be more about the article looking at altzeimers etc rather than longevity or Olympic-level athleticism than owt else!

[gavin]

The DNA of retroviruses has remarkable similarities to the casettes used to create a GM line. Genes with promoters, just a couple essential for the thing to work or maybe one, with flanking sequences to make the transfer work well.

Yes, the paper is about the mechanisms of Altzheimers and possibly a whole other range of conditions, and also the propsects of novel treatments and vaccines. Amazing stuff. But it lifts the lid on the fact that the genomes of humans, other animals and plants are not just littered with but in part built on genes from viruses and virus-derivatives. They replicate and hop around, then they mutate over time and lose their identity. The constants are the genes themselves and these are mostly maintained as they are by selection - over evolutionary time - essential to the survival of the organism. Duff ones are dead meat along with the individual carrying them. Unintended consequences are the norm. This is nature. Unintended worse ones are lost from the gene pool. Unintended changes that are neutral are allowed. Unintended better changes - for the time and circumstance - persist and thrive.

Does this mean that everyone should relax about GM? No, of course not! But a lot of the hysteria whipped up just seems alien to the working biologist. The act of inserting a gene of known type may have the effect intended from the understanding of the gene. It might also have unintended effects. Sometimes, depending on what the gene does and exactly where it sits. So test it first, that is all.

[beeanne]

By "unintended consequences" I only really meant unintended by the scientist, am not sure that Mother Nature sits thinking through the impact of introducing virus' to genes....

GM crops aren't necessarily sterile (or are they?). Can even the most rigourous testing really show that the interaction between various differnt types of GM plants and the various non-GM plants can give us no problem? I'm far from convinced that the testing ever could be "enough".

[gavin]

People are now really wound up about GM, at least in the West. I was speaking to some passing Chinese scientists on Wednesday. Their society has quite a different attitude.

In the context of people on edge, no amount of testing can ever be 'enough'. There will always be some doubt out there. When society gets in a tizz about something new it can take a generation before people relax, unless of course people see direct benefit to themselves, then they are prepared to take the (small) risk. Mobile phones and brain cancer maybe, there could be a long list. Look back and you will see concerns that seem laughable now but perhaps were understandable in their time. The risks of high-speed transport such as the burgeoning train network in Victorian times when some wouldn't go on them for fear of physiological difficulties due to the forces on the body. Of course mass transport (and other modern ways of living) *is* seriously damaging for the planet and perhaps we should have thought carefully about that.

My perspective is that of a scientist who, at one time, was partly working on GM for the common good. The technology was bought up and controlled by a few big companies, and the reaction of the public, amplified by vocal and often misleading campaigning meant that public good work stopped. As a technology it doesn't scare me in the least, though I am aware that being too gung-ho can lead folk to doing things that have consequences. It was also over-sold and pushed down people's throats as the answer to everything when it plainly isn't. But at its heart it is simply a tool that plant scientists could use to do good, in the right context and when applied carefully.

G.

PS No, they are not necessarily sterile. Just pretty normal organisms with a couple of extra genes in most cases. Not much different from the crops they may otherwise be - yet those crops are often quite different from their wild ancestors and taken to parts of the world where they were never found before.

[beeanne]

So... at worst it would be like introducing Japanese Knotweed on steriods, and the risk is worthwhile?
Are we risking interbreeding to make significant range of plants (including wild ones) resistant to insect attack? And if we do that, surely then we've just destroyed huge areas of habitat- not becuase we farm it, but even wild areas would become inhospitable. It won't just be agricultural crops that will be GM; am sure there'll be (eg) roses or whatever that won't "feed" greenfly (poor blue-tits, what will they do then?).
We're continuing to cheerily invent technology that will allow us to have huge areas on mono culture which might as well be concrete as far as insect etc are concerned.
I can see a humanitarian argument for researching staple crops which developing countries rely heavily on. But that's not where the line is drawn. It won't save the world from starvation, it might delay that point at the very best, and at some considerable environmental cost.

[Jon]

It is the monoculture aspect which is disastrous for the environment rather than the tabloid 'frankenfood' headlines.
I don't know how invertebrates or anything else can thrive in that kind of roundup ready environment due to lack of forage.
Like you say, might as well be concrete.

And as in the link Doris posted, there is something odd about almost all current maize varieties needing to be seed treated as I always found it one of the most reliable crops to grow, one which suffered from very few pests and parasites. But I was never involved in growing more than a couple of acres and we grew a heritage variety. The most important aspect was making sure there was enough nutrient/manure in the soil and plenty of water when cobs are forming as maize is a greedy feeder.
Some crops are next to impossible to grow successfully on a large scale without chemicals, chillies, brassicas, potatoes spring to mind.

The only chemical I use on my allotment is bordeaux mix on the spuds, usually get away with just one or two applications when there are optimum blight conditions.
Pests like white fly make growing courgette and pumpkin next to impossible. In a hot climate the pests and parasites can reproduce at an incredible rate.