The transfer of genes between unrelated organisms happens. All. The. Time.

Sep 28 2012 Published by under [Education&Careers]

The regulation of GMO foods is a pretty hot topic right now. Europe requires GMO foods to be marked and there are states, such as California, who are considering similar legislation.

Most people who are pushing these regulations argue that moving genes from one organism to another is "unnatural" and potentially dangerous. The problem with that stance is that it is completely at odds with the natural world. We can watch the movement of genes between unrelated prokaryotes in real time (think, the spread of antibiotic resistance) but this process is not, as often believed, relegated to the ranks of the non-eukaryotic world.

Among the many things the modern genomic age has taught us, it has become unambiguously clear that genes move between unrelated eukaryotes. Examples abound, but a review of the Choanoflagellate (Monosiga brevicollis) genome (Tucker 2012) shows that there are roughly 1000 genes of foreign affiliations encoded there. Choanoflagellates are the sister group to Metazoans (animals), so they are not some obscure and distant branch of life (unless you only think about rats or flies, then maybe they are). And much like other organisms that have been examined, the foreign genes come from a wide range of organisms, including vertebrates, plants, algae and bacteria.

And whereas the presentation of these data is a bit dubious at times(how often do you see "phylogenetic trees" with no support values and no indication of what kind of tree they are or what models were used?) the fact is that this is not a unique case. EVERY genome tells a similar story, to varying degrees.

So if you want to make a case against GMOs, fine. Just don't use the "unnatural" gene transfer angle as the main thrust of your argument. It just shows you have no appreciation for how much nature likes to mess with things.

Tucker RP (2012). Horizontal Gene Transfer in Choanoflagellates. Journal of experimental zoology. Part B, Molecular and developmental evolution, 1-9 PMID: 22997182

15 responses so far

  • Patchi says:

    The other problem is that a lot of people don't understand that all agronomic crops were man-made. The "natural" species were either inedible or not as flavorful as most consumers would want nowadays. The crazy things breeders do to get new varieties are sometimes scarier than introducing a single gene in controlled conditions, but most people don't hear about the former.

  • proflikesubstance says:

    Honestly, I didn't even want get into that but it's absolutely true.

  • The Australian equivalent of Rush Limbaugh once attacked David Suzuki for claiming that genes might "escape" from GMO canola into local plants. Species are isolated from each other, he proclaimed, and Suzuki must be a very bad scientist if he didn't know that (this was back in 1996, when I was starting my PhD). In fact both he and Suzuki were mistaken, in that genes introgress all the time, and this is, as you say, quite normal (and unpredictably beneficial or deleterious); just not a problem for GMOs specifically.

  • DrugMonkey says:

    grafted fruit trees.

  • becca says:

    This is 100% true but a terrible argument, as it points out exactly how inevitable it is that antibiotic resistance genes in GM organisms will escape into previously treatable pathogens.

  • [...] The transfer of genes between unrelated organisms happens. All. The. Time. Venture firms see signs of rebirth in life sciences A Pottery Barn rule for scientific journals Don’t Step in That Sh*t: How the GMO-Study Authors Played the Media The WEIRD Psychology of Elephants [...]

  • JohnV says:

    Guess we will just have to eschew treating people with glyphosate for those infections then 🙁

  • becca says:

    JohnV- when was the last time you tried to isolate a recombinant bacterial strain without using selective plates?
    Some of the GM crops do indeed have ampicillin resistance left in from the cloning process.
    Do you even bother to learn any of the science before you carry water for Monsanto's lawyers who love to sue farmers?

  • Viola says:

    Yeah, the chance of remaining ampicillin resistance is way too dangerous. Especially since the development of antibiotic resistance is completely unknown in US agricultural systems right now.

    We should totes go back to mutational breeding, where we just bombard the entire organism with gamma radiation and take what looks best. I'm sure there are never any undetected changes resulting from that type of plant breeding.

  • Hulk says:

    We should totes go back to mutational breeding, where we just bombard the entire organism with gamma radiation and take what looks best.


  • JohnV says:

    haha wow becca uses the pharmashill (monsantoshill) gambit on me. how amusing.

    anyhow as part of my phd in microbiology i did select for recombinant bacteria in graduate school that didn't necessitate antibiotics , thanks.

    whats really neat, and apparently only covered in my "how to be monsanto's slave and/or piss off neo-amish" handbook and not in conspiracy theorist classes at google university, is that you can have selective plates that don't make use of antibiotics.

    shocking i know, that one can be a microbiologist without using kilograms of carbinacillin every day.

    my training was from 2001-2006, so by that point DNA had been invented and genes (and whole genomes :o) had been sequenced so the general concepts of horizontal gene transfer were covered as part of my training. it didn't even require a weekend retreat to monstanto's fortress of solitude. that was for brainwashing.

    and just to satisfy your conspiracy theories, i am currently employed as a microbiologist by a large public university studying genomics of bacterial isolates of cystic fibrosis patients. in 2 months ill be starting a mostly identical position at a private university.

    i've never had funding from a private company. my graduate work was funded by the USDA (zomg totally in bed with monsanto). my first post-doc was funded by DTRA and my second post-doc was funded by the NIH.

    now, if you will excuse me, i have to go figure out how to spend this months "water-carrying" stipend. i'm thinking i might buy a bag of round up ready corn seeds and sprinkle it in some neo-amish subsistence farmers field so that my corporate overlords can sue them to death.

  • proflikesubstance says:

    I assumed you were saving up for the corn oil to fill your water bed.

  • becca says:

    Viola- And how many members of the general public are actually familiar with the gamma irradiation process? And do we really want to try to win that argument, considering possible unintended consequences on the science communication front for the Hippies afraid of radiation?
    I guess it might depend whether you think natural gas or nuclear is a better bridge fuel, but given how my Dad (whose scientific education is minimal, but still probably better than average) wants to keep sending me "Cell phones are dangerous" news stories (despite his 30+ year tobacco habit), I really am inclined to believe that paranoia about radiation wouldn't be any better than paranoia about genes.

    (NB: yes, I am completely aware that irradiating seeds don't make them radioactive, and that microwaves aren't ionizing, and that for that matter irradiating food is from a public-health standpoint a bang-up idea... but these are places there will be misinformation about)

    JohnV- if you've worked in micro labs, and also e.g. cancer labs*, you know they approach microbes very differently. Is it reasonable to play mutagenesis games without antibiotics? Of course. Is that actually how people choose to do it, for the vast majority of molecular scientists who have never cultured anything other than E. coli and are using it solely as a means to a genetically modified end? Nope.

    *Not picking on cancer biologists, I just mean generic molecular biologists who aren't trained as microbiologists first.

    Look, I'm not opposed to genetically modified crops. Though I am opposed to leaving ampicillin resistance genes in because... uhm, I really don't know why they leave 'em in.... I mean, we both know it's not really that hard to get around them. Doesn't it seem... sloppy?

    What I am opposed to the same old idiotic debate talking points on this topic. Yes, HGT happens. No, that doesn't make GMO products "natural", as people usually intend the word to mean. If you look at the history of agriculture, it's one "unnatural" (i.e. human-modified) process after another. Finding penicillin on mold is a lot more "natural" than turning teosinte into anything I'd want to eat. The key about GMO is not one of category (e.g. "natural" organic agriculture vs. modernized GMO agriculture), and those who say that are making a mistake. But there is a difference in degree. GMO speeds things up immensely. That's kind of the point. Driving in a car makes people unnaturally faster than running (with some relevant implications for our ability to react at high speeds). Does that make cars bad? Nope, but it also would be asinine to say "well we rode horses and llamas first, so cars are entirely natural".

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  • lauren says:

    There are no antibiotic resistance genes left in current GMO crops. It is now all "markerless" transgenics. Where genetic insertion is tracked with a benign DNA barcode and tracked by sequencing.
    Your point is moot.

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