October 31, 2010

Species Being Tracked By DNA Barcodes

Every species is being tracked through a DNA barcode in an attempt to keep track of the ones that are endangered, as well as those being shipped across international borders as food or consumer products.

Researchers believe mobile devices will one day be able to read these digital strips of rainbow-colored barcodes to identify different species by testing tissue samples on site and comparing them to a database.

Scientists using fragments of DNA are building the International Barcode of Life Project (iBOL) to create a database of all life forms.

"What we're trying to do is to create this global library of DNA barcodes -- snippets, little chunks of DNA -- that permit us to identify species," Alex Smith, assistant professor of molecular ecology at the University of Guelph's Biodiversity Institute of Ontario, told Reuters.

Scientists have also found that nearly one in four fish fillets are mislabeled in North America after referring to the library, which has 7,000 species of fish DNA barcodes.  

Researchers use a short section of DNA extracted from a standardized region of tissue in order to retrieve the barcodes.  

The barcode can be publicly viewed online by signing up for a free account at the site for Barcode of Life Datasystems (BOLD).

The DNA barcode sequence can be used to identify different species so that a specialist can identify the species once technology is available.

The library has over 87,000 formally described species with barcodes filed and over 1 million total barcoded specimens.

According to Smith, humans live among at least 1.9 million named species.  Scientists estimate iBOL will have barcodes for all 10 million of multicellular life within the next 20 years.

"Most of life on the planet is not polar bears and Siberian tigers -- most of life on the planet weighs less than a gram, is less than a centimeter long, and isn't visual. It experiences the world through taste and smell and we're not aware of its existence," Smith said.

The library is meant to also help with routine aspects of the glacial economy.  That includes jobs like ensuring the salmon or trout in markets and restaurants is accurately identified, or determining whether foods or other animal products crossing international borders are what they say they are.

Smith said the barcodes will dramatically reduce the time food shipments are held up at borders.  

Bob Hanner, associated director of the International Barcode of Life project, said the DNA barcode library will also help prevent the illegal exploitation of animals.

"Obviously trade in endangered species, in terms of the black market, is second only to narcotics right now," Hanner told Reuters. "So it's a big deal to be able to identify if something is farmed alligator skin or endangered Cuban crocodile when it is involved in international commerce, and once it's tanned into a leather, these things can be very challenging."

"The time horizon for bringing in these kinds of new platforms for detection really depends on how quickly the public sector can motivate to complete the reference sequence library," Hanner said.


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