Features
A Genetic Tattoo
Public, media interest in DNA testing driven by concerns about human health, consumer fraud, conservation
BY ANDREW VOWLES
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| Using DNA bar-coding, Prof. Robert Hanner, Integrative Biology, found that 25 per cent of seafood species are mislabelled and often sold as species of higher value. Photo by Martin Schwalbe |
Prof. Robert Hanner, Integrative Biology, got his first tattoo about two decades ago — around the time he got his first motorbike. He's still got a 1946 Harley, although it doesn't get out much these days. Neither do those tattoos, except when he wears his sleeves unbuttoned. Then it's hard to miss the intricate designs covering his wrists and what's visible of his forearms.
Look hard at those designs and you'll find what Hanner calls “signposts” to his evolving interests over the years. For instance, that whimsical bug perched on a toadstool on the inside of his right forearm was added during his graduate studies in biology at the University of Oregon.
He hasn't had a tattoo done for a while, but it wouldn't be difficult to come up with a motif to capture his work at Guelph since 2005.
“A DNA bar code wouldn't be inappropriate,” says Hanner, associate director of the Canadian Barcode of Life Network based at U of G's Biodiversity Institute of Ontario (BIO).
Never mind his arms. DNA bar-coding itself has gotten plenty of ink recently, with coverage in newspapers and magazines as well as broadcast airtime at home and abroad. Notable was a study Hanner published in late summer reporting that one-quarter of seafood species are mislabelled and often sold as species of higher value.
Using fish samples from restaurants and markets in Guelph, Toronto and New York City, he and master's student Eugene Wong used bar-coding technology developed at Guelph to identify individual species. Hanner and other researchers at the BIO are now working with the U.S. Food and Drug Administration to validate DNA bar-coding for regulatory use in authenticating seafood, a move they expect Canadian regulators will emulate.
After they published their findings in the Journal of Food Research International, the story raced through media outlets worldwide, including the Globe and Mail, National Post, New York Times, CNN, CBS, Global News and CBC.
Two months later, DNA bar-coding is the subject of articles appearing in both Scientific American and Wired magazine. The former piece was co-written by Prof. Paul Hebert, Integrative Biology, director of the BIO and the scientist who first used a small DNA fragment to differentiate between species of organisms.
Those new articles follow a long list of stories in print media in recent years that have looked at DNA bar-coding, including cover stories in Nature, New Scientist, Science News, Canadian Geographic and L'actualité.
What accounts for the interest in the topic, not only in scientific journals but also in mainstream media and, by extension, among the general public?
Hebert says it's not about the intricacies of genetics, even though the technology rests on analyzing bits of genetic material in tissues of animals from insects to whales. DNA bar-coding touches the public in a more visceral way than projects that are more esoteric, he says.
“We are an interesting big science project. Most other big science projects involve objects that are too far away to ever touch, such as astronomy, or too small to ever see, such as particle physics. Biodiversity is within everyone's reach, and this is, I think, reflected in the ongoing attention to our work.”
Hanner points to the direct effects of the recent seafood study. First, there's the consumer fraud issue of fish species being deliberately mislabelled. Add the human health aspects, including food allergies and the risk of illness or even death if someone eats something that's incorrectly labelled. Then there's the environmental and conservation side: Is that a piece of Pacific halibut or is it a fillet from its ecologically threatened Atlantic cousin?
There's also the “CSI effect,” although Hanner confesses that sometimes public expectations — fostered paradoxically by media attention, including prime-time TV dramas — run ahead of scientific realities. With a wry smile, he says: “My mom asked me what I do. I said: ‘DNA bar-coding.' She said, ‘You mean we don't already do that?'”
Alex Smith, a research scientist at the BIO, allows that retail bar codes aren't a perfect description of what goes on in the BIO and in research labs worldwide under national and international bar-coding groups. But the idea of DNA bar-coding gives most people a way to picture what might otherwise remain complex concepts in genetics and molecular biology, he says.
“It works as an analogy. As an entry point, people know what bar codes do.”
He echoes Hanner's point about the importance of knowing one species from another. It costs money to clean up invasive species such as zebra mussels in the Great Lakes. Government agencies can grasp the bottom-line significance of knowing which species is which, says Smith.
The same idea applies to controlling any number of insect pests. Take wasps, for example. Smith, Hebert and several American researchers used DNA bar-coding to uncover more than 300 provisional species of wasps in a particular subfamily — nearly double the number of species that were previously known.
That work, published in August's Proceedings of the National Academy of Sciences, found its way into Science Daily News, National Geographic and Discover magazine.
“Combining morphological analysis, ecology and DNA bar-coding allowed us to make much more fine-scaled hypotheses of parasitic diversity and host specificity than any one of these elements could have produced on its own,” says Smith, explaining that zeroing in on particular species might enable us to control pests more accurately.
He says one day it might be possible to arm amateur naturalists — and even restaurant and market patrons — with a handheld device that would use bar-coding and a snippet of tissue to easily identify a specimen in the field or on your dinner plate. That hands-on aspect of the technology — call it GBS (global bio-identification system) combined somehow with a cellphone, personal digital assistant and maybe a global positioning system — echoes Hebert's comments about accessible science.
Says Smith: “It's hard to get people interested when they can't learn about things in their hand.”
If it helps to know which animal species is which, it's also useful to distinguish among plants for anything from forensic investigations to tracking endangered and weedy species. But unlike the particular genetic sequence in animals — including insects — the gene in plants varies too widely to permit DNA bar-coding.
That may change soon, following a study this summer by scientists at the BIO and at other Canadian institutions. The group, including Prof. Steve Newmaster and lead author Aron Fazekas, a post-doc in the Department of Integrative Biology, developed a short list of genetic markers that together proved more than 70-per-cent accurate in identifying plants.
The study appeared in late July in PLoS One, published by the Public Library of Science.
Environmental, economic or human health impacts hit home with the public, says Hanner, and all of that media attention is gratifying and important. But as with other biologists involved in DNA bar-coding, he is keenly interested in what the technology can tell us about biodiversity and nature.
That includes the kinds of basic questions he used to ask his grandfather on fishing expeditions in his native Michigan — and the same kinds of things he explores today on nature outings with his five-year-old son, Harland.
“That's the side that's exciting.”
This fall, Hanner visited Ethiopia for a scientific meeting involving the Fish Barcode of Life (Fish-BOL) initiative. He's the campaign co-ordinator for this international project, which has bar-coded more than 5,000 of the approximately 30,000 species of fish.
He will discuss Fish-BOL bar-coding progress and applications Nov. 28 at 12:30 p.m. in Room 3317 of the science complex, as part of his department's “Loaves and Fishes” seminar series.