Tuesday, September 09, 2003
The scarlet letters: "GM"
Last weekend, I took a day trip to Maine to see the coast and eat lobster. Along the way I happened upon what I assume is a transport vehicle for lab mice being ferried to and from Jackson Labs, a repository of genetically altered mouse strains and a wonderful resource for biologists. For some reason, this truck was posted with the warning, "Caution: Genetically Engineered Mice."
I have been confused by this sign for the better part of a week. Is the request for increased driving vigilance intended to protect the mice or humans? Perhaps, like the "Caution: Baby on Board" warnings, we are being reminded that the consequence of bashing one's car into another vehicle might be the injury of small creatures. Surely these mice are not wearing seat belts, and I cringe to think of the havoc that would be caused by a rear end collision. But since we never see such signs on the back of horse trailers, for instance, are we to assume that large animals would fair any better in a car accident? My guess is that they wouldn't. Which leads me to wonder how one might engineer tiny mouse-sized car seats.... or equine air bags.... hmph.
More likely, I think, this is a warning against the accidental release of transgenic animals into nature. But is such a warning warranted? Is there really any danger posed by the release of a truckload of transgenic mice?
First, its important to note that transgenic mice are NOT mice that carry diseases like hanta virus, the plague, or rabies. If you want to study such contagious diseases, you need to apply for special permits, leap many bureaucratic and technical hurdles, and work within specially contained facilities. (This is as it should be... I'm not implying otherwise.) I am not an expert is such matters, but I am fairly confident that shipping sick animals around in trucks is off-limits. But if you want to find sick animals, just look in the wild. On the other hand, laboratory mice, including transgenic animals, have been extensively screened for infectious diseases and are some of the least contaminated creatures on the planet. In fact, most sanitary precautions that are taken when entering a mouse room (booties, lab coat, gloves, hair net, etc.) are intended to protect the mice from picking up any germs that YOU happen to carry in.
Most importantly, however, I can't think of any transgenic mouse strains that would pose an environmental, agricultural, or human health threat if released into the wild. In general, transgenic mice have either been engineered to have something wrong them or to carry harmless markers that are only useful to scientists. In the first case, deleterious mutations would make them easy prey or prevent them from reproducing. In the other case, it makes no difference if a mouse carrying the gene for green fluorescent protein in a subset of its pancreatic cells escapes into the wilderness. (But if it does and you find it, please send it to me.) Also, mice are indigenous to the northeast, so they don't pose the risk of a foreign species, like cane toads do in Australia.
I don't know for sure, but I suspect that this warning has been posted in accordance with some sort of regulatory policy, not voluntarily by Jackson labs or because there is any real danger. If so, this sign is the modern equivalent of sewing a big scarlet "A" on one's clothing. Read: these people are BAD and what they do is DANGEROUS and we DISAPPROVE. If, however, there are "dangerous mice" being carted around New England in a horse trailers, I think that the standard Biohazard symbol would probably be more appropriate.