Genetic Modification in Food

[wellAlbidarned]

Are you actually just frightened of a zombie apocalypse?

a plant zombie apocalypse wouldn't be very exciting tbh

 

[uvelocity]

young ****s these days

 

[wellAlbidarned]

everyone knows you just spin them away though, no challenge.

 

[Ruckus]

And you don't need to look to dogs - most of the food you eat isn't the wild type, it's been heavily selected for over thousands of years (e.g bananas without seeds).

Don't know much about genetics, but I don't think the wild banana/selective breeding analogy is comparable at all to genetic engineering. First line off wiki: "Genetic engineering, also called genetic modification, is the direct manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest."

You then click on foreign (recombinant) DNA, and you get this:

"Recombinant DNA (rDNA) molecules are DNA sequences that result from the use of laboratory methods (molecular cloning) to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms."

Genes don't operate in isolation, so I'd imagine knowing exactly how gene expression is regulated plus epigenetic stuff would make it a complex problem. Most studies on GM foods don't really show any safety issues, but I think there are some acknowledged limitations in what the testing accounts for, and I'm not sure there are many on long term studies either. Overall there are probably very good early signs, but I still wouldn't be going nuts with the technology on a large scale yet. Gotta surely take a very measured, slow approach with something like this, especially given the understanding of complex genetics processes is still in a work in progress.

 

[silentstriker]

Don't know much about genetics, but I don't think the wild banana/selective breeding analogy is comparable at all to genetic engineering. First line off wiki: "Genetic engineering, also called genetic modification, is the direct manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest."

You then click on foreign (recombinant) DNA, and you get this:

"Recombinant DNA (rDNA) molecules are DNA sequences that result from the use of laboratory methods (molecular cloning) to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms."

Genes don't operate in isolation, so I'd imagine knowing exactly how gene expression is regulated plus epigenetic stuff would make it a complex problem. Most studies on GM foods don't really show any safety issues, but I think there are some acknowledged limitations in what the testing accounts for, and I'm not sure there are many on long term studies either. Overall there are probably very good early signs, but I still wouldn't be going nuts with the technology on a large scale yet. Gotta surely take a very measured, slow approach with something like this, especially given the understanding of complex genetics processes is still in a work in progress.

We don't have the ability to create genes from scratch yet. When you breed two species of plant, vegetable, or whatever, you're going to get a sequence not found in either (it will be a mix). Except now you can do it in a lab. Yet we don't require massive testing for every food product created by bumbling around in a field creating new genetic sequences. Why? Because you're just eating it - it's DNA isnt becoming a part of you or anything! It's digested all the same way - whether you eat fish, a vegetable or a hypothetical "frankenfood" fish-vegetable.

 

[Ruckus]

We don't have the ability to create genes from scratch yet. When you breed two species of plant, vegetable, or whatever, you're going to get a sequence not found in either (it will be a mix). Except now you can do it in a lab. Yet we don't require massive testing for every food product created by bumbling around in a field creating new genetic sequences. Why? Because you're just eating it - it's DNA isnt becoming a part of you or anything! It's digested all the same way - whether you eat fish, a vegetable or a hypothetical "frankenfood" fish-vegetable.

Artificial gene synthesis - Wikipedia, the free encyclopedia?

And I don't think many potential arguments against GM food are to do with the DNA becoming part of you, they are to do with the metabolites produced by the new DNA (and just other stuff like how the inserted DNA effects the expression in other genes etc.). My knowledge of genetics isn't good enough to assert this, and I cbf researching it, but it would surprise me if recombinant DNA was effectively the same as any new genetic sequences created through processes like selective breeding.

 

[smalishah84]

yeah....I am not very well versed in genetics either but I would have been thinking along the lines of what Ruckus is saying.

btw IIRC some groups have been blaming genetically modified food for being one of the major causes of cancer. Any truth to such claims?

 

[Ruckus]

'One of the major causes'? I highly, highly doubt that. From the literature review I read, there weren't any studies that, with proper evidence, indicated carcinogenic effects. There were a few that possibly suggested some other problems, but the data/methodology was limited etc. etc. I think that basically sums up the whole issue as it stands anyway; good signs the technology is safe at the moment, but still some acknowledged areas that need to be researched + a need for more long terms studies.

 

[Shri]

Would be cool to have protein rich/vitamin rich/low carb rice one day.<_<

 

[silentstriker]

Artificial gene synthesis - Wikipedia, the free encyclopedia?

And I don't think many potential arguments against GM food are to do with the DNA becoming part of you, they are to do with the metabolites produced by the new DNA (and just other stuff like how the inserted DNA effects the expression in other genes etc.). My knowledge of genetics isn't good enough to assert this, and I cbf researching it, but it would surprise me if recombinant DNA was effectively the same as any new genetic sequences created through processes like selective breeding.

What new metabolites are you talking about?

 

[Ruckus]

Specifically? No idea. I was speaking in general terms, because you were suggesting that an argument against GM was to with the direct assimilation of the DNA into your body - which just isn't a very big concern. It's the unintended metabolic effects and how the inserted gene/s interact with other genes which is the main research area. I.e. in some way or another, it comes down to the products of the process, which is basically what your eating, and what can remain potentially harmful to your body despite digestive processes - e.g. are potential allergens being produced? Are carcinogenic metabolites being produced? Has the new food become deficient in certain nutrients? Etc. Some of those concerns could, no doubt, be targeted towards conventional breeding as well, but if anything that just means there needs to be stricter regulation there as well.

 

[silentstriker]

But as you said, that's no different whatsoever to the thousands of years of cross breeding that we've been doing. I think it's way overkill - generating a random metabolite that's so poisonous and yet insidious to escape detection is unlikely - but as you mentioned that's a problem for all foods, not specifically to GM foods.

 

[Ruckus]

But as you said, that's no different whatsoever to the thousands of years of cross breeding that we've been doing. I think it's way overkill - generating a random metabolite that's so poisonous and yet insidious to escape detection is unlikely - but as you mentioned that's a problem for all foods, not specifically to GM foods.

I'm not sure of that, evidence? Unintended effects are just a natural product of genetic processes, so it doesn't clarify much in itself. I'd want to to know things like if the frequency is the same, and if the diversity and type of potential unintended effects is in any way different for recombinant DNA. As the wiki article said above with recDNA your "creating sequences that would not otherwise be found in biological organisms", so I don't think it's that unreasonable to question whether the ways in which the inserted genes interact could be different to conventional breeding. It might be effectively the same (I don't know), but nonetheless it doesn't change the fact that all types of 'new' food sources should be monitored.

And I don't think it's a case of metabolites being 'so poisonous' - those would be the type of thing that testing immediately can account for. The problem is the ones that only have noticeable effects in the long term (often because their action in the body involves very indirect and complex mechanisms). Those are the things that are difficult to test for, and where you absolutely need long term studies.

 

[silentstriker]

I'm not sure of that, evidence? Unintended effects are just a natural product of genetic processes, so it doesn't clarify much in itself. I'd want to to know things like if the frequency is the same, and if the diversity and type of potential unintended effects is in any way different for recombinant DNA. As the wiki article said above with recDNA your "creating sequences that would not otherwise be found in biological organisms", so I don't think it's that unreasonable to question whether the ways in which the inserted genes interact could be different to conventional breeding. It might be effectively the same (I don't know), but nonetheless it doesn't change the fact that all types of 'new' food sources should be monitored.

When they mean creating things "not found in nature", that's us taking a specific gene (say from a pear) and inserting it somewhere in an apple - thereby creating a new genetic sequence. When we purposefully cross breed two species, we are also creating new gene sequences not previously found in nature - except we have very little control over the end product. Hell when you were conceived, your genetic sequence was a product of genetic recombination from your parents. And unless you have a twin, it was a unique sequence not previously found in nature!

And I don't think it's a case of metabolites being 'so poisonous' - those would be the type of thing that testing immediately can account for. The problem is the ones that only have noticeable effects in the long term (often because their action in the body involves very indirect and complex mechanisms). Those are the things that are difficult to test for, and where you absolutely need long term studies.

You are talking about a brand new chemical compound in food that did not exist previously which could potentially cause problems. I'm not aware of anything like that happening - I'm not even sure the mechanism by which it COULD happen at a higher frequency than in traditional farming methods.

 

[Ruckus]

When they mean creating things "not found in nature", that's us taking a specific gene (say from a pear) and inserting it somewhere in an apple - thereby creating a new genetic sequence. When we purposefully cross breed two species, we are also creating new gene sequences not previously found in nature - except we have very little control over the end product. Hell when you were conceived, your genetic sequence was a product of genetic recombination from your parents. And unless you have a twin, it was a unique sequence not previously found in nature!

This is from the same page: "Recombinant DNA differs from genetic recombination in that the former results from artificial methods in the test tube, while the latter is a normal biological process that results in the remixing of existing DNA sequences in essentially all organisms."

As far as I was aware (once again might be wrong - this is like high school biology!) genetic variation is basically a result of the resorting of homologous genes - so even if you get a new genetic sequence different to either parent, the chromosome will still have genes coding for the same traits (e.g. eye colour) and there will still be some similarity in the sequence. On the other hand, if you are using recDNA technology, you can end up with things that just won't occur naturally (unless by mutation or maybe some genetic replication error). E.g. the human insulin gene being inserted into bacteria for the production of insulin. That's the actual addition of a gene that the species didn't even have before.

 

[Son Of Coco]

So name them.

At this stage all you're doing is just trotting out meaningless half-statements with variable basis in actual fact, and asserting without evidence (and please lay off the 'ebil corporations' bull****, it's tiresome). For example, your claim that GM crops are exorbitantly expensive, to the point where we shouldn't bother - evidence?

Monsanto

Edit: A guy at school who covered this sort of stuff in his Masters did a fascinating 2 hour presentation (with English as his second language) about GM Foods. It's his area of expertise...if only I could remember some of his main points. I did take notes. Maybe I can just get him to sign up to CW and reproduce it all here.

 

[silentstriker]

What was his main thrust?

 

[silentstriker]

This is from the same page: "Recombinant DNA differs from genetic recombination in that the former results from artificial methods in the test tube, while the latter is a normal biological process that results in the remixing of existing DNA sequences in essentially all organisms."

As far as I was aware (once again might be wrong - this is like high school biology!) genetic variation is basically a result of the resorting of homologous genes - so even if you get a new genetic sequence different to either parent, the chromosome will still have genes coding for the same traits (e.g. eye colour) and there will still be some similarity in the sequence. On the other hand, if you are using recDNA technology, you can end up with things that just won't occur naturally (unless by mutation or maybe some genetic replication error). E.g. the human insulin gene being inserted into bacteria for the production of insulin. That's the actual addition of a gene that the species didn't even have before.

Yea but humans are one species. When you breed two different species - you do get a new gene which is the same as your insulin gene example. And you also bring up a great example about gene mutations - we don't test every piece of fruit for genetic mutations - even though we undoubtedly eat millions of pieces of fruits, vegetables, and meats with all sorts of mutations.

 

[Ruckus]

Yep that's true, but you brought up the example of human genetic recombination.

There is hybridization within plants (and some animals, but won't go into that here) species where you get polyploidy - where the offspring actually have a different number of chromosomes to the parent (modern wheat strains are an example). But once again I'm not sure if you can actually call that equivalent to what's achieved in some recDNA situations. "A number of conditions exist that limit the success of hybridization, the most obvious is great genetic diversity between most species". All hybrids that are naturally occurring or artificially selected have been bred from different species that are relatively similar genetically. So I'd want to know if, because of the closely shared ancestry, it means how the genes interact and how expression is regulated in the new species is in some way more coordinated than in, say, a tomato with a fish gene stuck into it - which is an example of genetic diversity that just won't occur naturally (except maybe in Tasmania). Because there's a lot more than just genes which code for the obvious physical attributes - there's a whole array of regulatory genes etc. which have very important roles in determining how the organism functions (which I'm sure must have 'co-evolved' in some sense). I don't know the answers to these things though, and it's seemingly pretty hard stuff to find out.

I haven't looked at this genetic stuff since basically high school, but I've gotta to say it's damn fascinating isn't it? Makes me kind of wish I studied it at uni.

 

[silentstriker]

There is hybridization within plants (and some animals, but won't go into that here) species where you get polyploidy - where the offspring actually have a different number of chromosomes to the parent (modern wheat strains are an example). But once again I'm not sure if you can actually call that equivalent to what's achieved in some recDNA situations. "A number of conditions exist that limit the success of hybridization, the most obvious is great genetic diversity between most species". All hybrids that are naturally occurring or artificially selected have been bred from different species that are relatively similar genetically. So I'd want to know if, because of the closely shared ancestry, it means how the genes interact and how expression is regulated in the new species is in some way more coordinated than in, say, a tomato with a fish gene stuck into it - which is an example of genetic diversity that just won't occur naturally (except maybe in Tasmania).

There is no way for a body to know which genes it's closely related to vs. when it is not. It can't run an evolutionary tree and make that type of determination. I mean you and an apple probably share about half your genes. It's all just combinations of ACGT. Very simple changes - including a SINGLE BASE change can result in radically different product (we know very serious diseases where the difference between a perfectly healthy person and an extremely sick one is a single base pair change - one G to C or something like that). So there is very little advantage to being 'close'. In fact, it's probably a disadvantage, because a single mutation can sometimes create a product that's very similar in some ways (e.g it can interact with lots of things in the body it used to) but is in fact much worse - because now it stops the activity of all the things it used to interact with.

Because there's a lot more than just genes which code for the obvious physical attributes - there's a whole array of regulatory genes etc. which have very important roles in determining how the organism functions (which I'm sure must have 'co-evolved' in some sense). I don't know the answers to these things though, and it's seemingly pretty hard stuff to find out.

Yes, there are many regulatory genes - but I am not sure what that has to do with anything. If we insert a gene correctly, the regulatory genes will express that gene and we'll have a product (e.g Vitamin A). Or it might not be expressed, or expressed at a lower rate, and then we might have no (or very little) Vitamin A.

The thrust that I think you're making - that somehow the interaction of genes may create a bran new unexpected metabolite different, and yet dangerous, and yet would simply not be detected in a chemical analysis is pretty unlikely. Or rather, as I said, I don't know by what mechanism such a thing would be more likely than cross breeding species.