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maradyddOver the last 24 hours I've seen a lot of concern and speculation about what happens if one of my experiments somehow "goes out of control" and turns into some kind of "grey goo" event. It seems that there's a mistaken impression that I'm just randomly mutating things (perhaps with UV stimulation) to see what comes up. This actually couldn't be further from the truth, so let me explain what I'm really doing.
How Your Genes Work can be summed up in a single sentence: "DNA makes RNA makes protein." Your genes are instructions for making several different types of RNA, and those RNA molecules assemble the proteins that your body is made of and which make your body run. Some proteins are structural, some are enzymes used to catalyze chemical reactions (such as digestion), some are used to transport other molecules around (e.g. hemoglobin, which carries oxygen around in your red blood cells) -- proteins are everywhere. So, when I think about something I'd like for a cell to do, I start looking around for relevant proteins.
In the case of "let's detect melamine", I went to MetaCyc -- a browsable database of metabolic pathways -- and looked for proteins which interact with melamine. I found one, called melamine deaminase. It's the beginning of a metabolic pathway called the melamine degradation pathway, which -- go figure -- takes melamine apart. To use this reaction in our detector, we'll need to give some species of bacteria the ability to produce melamine deaminase, which means giving it the appropriate gene. To do that, we either extract the gene from a species that already has it, or we get a lab like IDT to make it for us. Then we insert the gene into a plasmid, which is a circular DNA molecule that a bacterium can "take up" in order to gain some new function.
So, no, there is no deliberate randomness going on here -- rather, it's a concerted effort to make just one type of bacteria do just one additional thing (or, really, some sequence of additional things). The whole experimental setup is also designed so that if I screw something up, the bugs die and that's it. And, naturally, I'm doing everything I can to make sure that stray spores, phages, and other contaminants don't end up in my experiments -- heat sterilization, alcohol sterilization, flame sterilization, you name it.
Do you need to worry about these synthetic bacteria degrading you? Only if you are a whiteboard or certain species of plastic fork.
How Your Genes Work can be summed up in a single sentence: "DNA makes RNA makes protein." Your genes are instructions for making several different types of RNA, and those RNA molecules assemble the proteins that your body is made of and which make your body run. Some proteins are structural, some are enzymes used to catalyze chemical reactions (such as digestion), some are used to transport other molecules around (e.g. hemoglobin, which carries oxygen around in your red blood cells) -- proteins are everywhere. So, when I think about something I'd like for a cell to do, I start looking around for relevant proteins.
In the case of "let's detect melamine", I went to MetaCyc -- a browsable database of metabolic pathways -- and looked for proteins which interact with melamine. I found one, called melamine deaminase. It's the beginning of a metabolic pathway called the melamine degradation pathway, which -- go figure -- takes melamine apart. To use this reaction in our detector, we'll need to give some species of bacteria the ability to produce melamine deaminase, which means giving it the appropriate gene. To do that, we either extract the gene from a species that already has it, or we get a lab like IDT to make it for us. Then we insert the gene into a plasmid, which is a circular DNA molecule that a bacterium can "take up" in order to gain some new function.
So, no, there is no deliberate randomness going on here -- rather, it's a concerted effort to make just one type of bacteria do just one additional thing (or, really, some sequence of additional things). The whole experimental setup is also designed so that if I screw something up, the bugs die and that's it. And, naturally, I'm doing everything I can to make sure that stray spores, phages, and other contaminants don't end up in my experiments -- heat sterilization, alcohol sterilization, flame sterilization, you name it.
Do you need to worry about these synthetic bacteria degrading you? Only if you are a whiteboard or certain species of plastic fork.
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(no subject)
Date: 2008-12-27 08:38 am (UTC)That said, I think you have about as much of a chance as creating grey goo to wipe out humanity as you do having a direct hand in the LHC creating a black hole to wipe out humanity. Yes, you personally -- that should tell you what I think about most doomsday scenarios. This sort of "fear of the mad scientist" goes back a long ways, and is especially prevalent in modern culture. I can think of dozens of movies where the premise is "well-intentioned but misguided mad scientist (or lab scientists working on government funded programs, the more realistic of the two mostly unrealistic scenarios) experiment with Things Nature Never Intended Man To Know, and Bad Things Happen. It obviously betrays an underlying anxiety about scientific advancement among the members of our society, but it is somewhat depressing when people take mostly irrational fears about one are of near-future science and apply them to other areas of newly-developing science. I hope, at least, that the histrionics who are seriously worried about grey goo realize that that is a nanotech scifi doomsday nightmare, and not a basic at-home biohacking one, and that they're just using that term for lack of established Canonical Thing To Be Afraid Of With This Area of Human Knowledge Advancement.
You're doing a good job managing these questions; better than I would have the patience for. Thanks for being the public face of this stuff -- I'm hoping people are coming away with their interactions with you with their concerns addressed and their fears explained and reasonably satisfied. They seem to be.
(Note, I don't fault people for having these fears -- society, through bad popular science articles and popular science fiction, haven't exactly been good at preserving realism when looking for sensationalist or thrilling new threats to create to further a plot, and the overall quality of scientific journalism is such that it's hard to tell a serious article about a serious technology apart from an article about a pseudoscientific synthetic hysteria, and thus no reason for those not familiar enough with the subject to realize what is unrealistic fluff and what is reasonable reporting. I suppose the problem is the need for mass media to appeal to the lowest common denominator of its readership.
(no subject)
Date: 2009-01-14 06:10 am (UTC)