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Scientists Modify Organism With Artificial Amino Acid
IndigoDarkwolf writes "The Beeb reports that biologists Sebastian Greiss and Jason Chin have genetically modified a multicellular organism (Caenorhabditis elegans, a tiny worm) to combine an amino acid not found in nature into a custom-built protein. The protein created by their genetically-modified worm contained a dye which glows when exposed to UV light. While previous work showed that genetic modification could incorporate non-natural amino acids into custom proteins for single-celled organisms, this is the first time an entire animal has been modified."
How is this different from those glowing Chineese pigs or those neon tetras with unnatural colors that are illegal in California?
Those involved taking a gene that created a naturally created protein using naturally occurring amino acids and then injected them, frankenstein style into another animal. These take an artificially modified gene that uses an artificial amino acid to create worms that glow. Did you read TFS?
So far in the Genetically Modified Foods debate, I've been arguing that, since the genes spliced into GMOs are genes that already exist in nature, GMOs really aren't the nightmarish cancer-causing foodstuffs people make them out to be and that GM foods are the only way we're going to support a population of 7 billion people on this planet just as nitrogen-fixing fertilizer caused a green revolution that allows us to support our current population size.
So what happens when we start splicing genes into organisms that don't exist in nature? When companies start wanting to work this stuff into our food, and the FDA and courts roll over to allow it unquestioningly, then I think I might start to side with the anti GM Food people. This could be a second green revolution, but with America gutting its science programs, there will be no one to make sure this stuff doesn't have horrible health repercussions.
i ~ Celebrating Science, Cyberspace, Speculation
The breakthrough here is not artificial biological fluorescence, which has been around for a long time. The breakthrough is also not that this is a fluorescent amino acid (as opposed to full proteins made up of many amino acids, like GFP, which is again what you're talking about), evidently those have been demonstrated for a few years. This is tricking an organism into -using- an artificial amino acid, a fluorescent one.
Being able to incorporate fluorescent amino acids into a protein -looks- pretty striking, but people have been able to get cells to attach a fluorescent protein onto other proteins for years. The fluorescence here was just an easy assay to tell if they had gotten the c elegans to use a different, entirely artificial building block. Fluorescent amino acids may turn out to be the biggest use for this discovery, but the real story here is that we have a new tool, not that the tool can be used to make organisms glow.
They did reprogram the worms. No doubt people have done DIY genetics with these worms before too. It's not as easy as genetic splicing with yeast or ecoli, but enthusiasts could definitely make their own transgenic worms in their garage. If you buy or make your own PCR machine, that's probably the biggest barrier right there.
It's the "amino acid not found in nature" that's the story here, not the "dye which glows when exposed to UV light".
They've modified the DNA of a multi-celluar organism to produce a non-natural amino acid. It's been done before, yes, but only in single-celled organisms. The sequence is
1) Take a fluorescing protein
2) Modify the protein so it only glows when contains_custom_amino_acid == TRUE.
3) Insert protein sequence in DNA
4) PROFIT!
The glowing pigs, cats, dogs, and fish omit step #2.
What part of "a well regulated militia" do you not understand?
The glowing Chinese pigs are using proteins and amino acids that already exist: we found the proteins in an existing animal, probably some deep-sea fish, then took the DNA responsible for the creation for those proteins, and spliced it into the genome of the pigs. Here, they decided on what protein they wanted ahead of time, with plain old chemistry, then crafted a custom DNA sequence for the purpose of creating that protein (apparently creating never-before-used amino acids in the process). Existing protein/DNA transplanted into new animal vs. new protein/DNA built from the ground up.
Here, let me karma whore and try my hand at one o' them car analogies: the first example is like taking the radio out of your truck and putting it in your Volvo, whereas the second example is designing an entirely new kind of playback machine, with the right interface and wires, then wiring it up to the Volvo.
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...who read 'orgasm' instead of 'organism'?
Actually, it's a little trickier than that. Worms have to be microinjected. But that hasn't stopped people from trying to make worm engineering widely accessible. This is the seminal work on the topic, I believe.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
I don't mean like haha, "I, for one, welcome our new C. elegans overlords" or tagging the story with whatcouldpossiblygowrong. I mean The Stand. Could somebody with a reasonable knowledge of GM organisms please offer some reassurance that this technique couldn't backfire in some disastrous way?
IAABIT (I am a biologist in training) and based on my knowledge, there's honestly nothing to worry about for this, because it is fundamentally a chemical change. You're gaining the ability to use amino acids other than the 20 that naturally exist, but at that low of a level all that you're gaining is more biochemical versatility. You're going to have to go much higher in terms of complexity and organization before you get something that could potentially pose a danger or what not.
It's sort of like changing one of the instructions in the instruction set of your CPU - would you be worried about malware at that point? I wouldn't say so. It's at the much higher levels that you would start to become worried when these fundamental chemical units (or instructions) start getting combined in novel ways that are potentially dangerous that you would really begin to worry about things. A simple categorical change in amino acid may or may not alter the large-scale properties of macromolecules which are responsible for the majority of biological function. This advance will simply give us the ability to have a greater range of freedom on which to conduct genetic engineering by opening up the possibility of using non-natural amino acids (and "natural" just means one of the 20 amino acids who happen to have been adopted for use by the first biological life forms) - it doesn't really say what the end phenotype will be because that depends on the way the amino acid is used.
Hope that made sense.
Cogito, ergo sum, fosho!
I mean The Stand. Could somebody with a reasonable knowledge of GM organisms please offer some reassurance that this technique couldn't backfire in some disastrous way?
Well, c.elegans doesn't cause disease, they eat bacteria. They are also far, far, far too macroscopic to be airborne even if they were to suddenly take a liking to human flesh.
As far as assurances that this technique couldn't backfire, there are nearly infinite ways that absolutely anything could backfire if you don't look at probability. Turning on your car could backfire in that the engine might explode due to a defect, could explode due to some quirk of quantum physics, could produce through the burning of hydrocarbons a new microorganism that would cause the end of the world. All fairly unlikely.
The best way to reassure you might be that biologists have, for years, been fooling around with the genetics of C. elegans. A lot. During a lab rotation a few years ago, I introduced an HIV protein into worms. Thus far I have not died a horrible death. One common technique to look for genes involves soaking the worms in mutagens. The goal being to get a worm with a mutation in one of its genes, for every single gene in the worm genome. That's a lot of completely random genetic fiddling. We're not juggling with vials of ebola here. With this specific case, this is an artificial amino acid. If the worm got out, it wouldn't find any of that amino acid, it would just be a normal worm basically.
With GMO, the most down-to-earth concern is that the mutations will get out into the population. That's not really a concern with these worms. They evolve so quickly that the lab strains are probably obsolete, having been used since the 50s or so, and they really don't affect us eating bacteria as they do. Weeds becoming resistant to roundup are exponentially more of a concern than genetically modified c.elegans.
Well, let's say these engineered worms escape into the environment. 1) the paper does not show whether the changes they made to the worm's genome are heritable, so the worm's offspring might not be able to incorporate the unnatural amino acids and the trait might go away after the escaped engineered worms die. Even if the trait is heritable, the paper suggests that the gene cassette they engineered into the worm gets lost from the genome over time, so after a few generations, the trait would likely be lost. 2) these worms do not have the ability to synthesize the unnatural amino acids on their own. They incorporate the unnatural amino acids into their proteins only when the researchers feed the worms large amounts of the unnatural amino acid. Without a source of unnatural amino acids, they are just slightly broken versions of a normal C. elegans worm.
Does this make you feel any better?