text-only page produced automatically by LIFT Text Transcoder Skip all navigation and go to page contentSkip top navigation and go to directorate navigationSkip top navigation and go to page navigation
National Science Foundation
News
design element
News
News From the Field
For the News Media
Special Reports
Research Overviews
NSF-Wide Investments
Speeches & Lectures
NSF Current Newsletter
Multimedia Gallery
News Archive
News by Research Area
Arctic & Antarctic
Astronomy & Space
Biology
Chemistry & Materials
Computing
Earth & Environment
Education
Engineering
Mathematics
Nanoscience
People & Society
Physics
 

Email this pagePrint this page


Press Release 08-146
DNA Barcodes: Are They Always Accurate?

Study questions reliability of some results

Photo of heron and its "DNA barcode".

This heron's "DNA barcode" provides information about its relationship to other animals.
Credit and Larger Version

August 25, 2008

DNA barcoding is a movement to catalog all life on earth by a simple standardized genetic tag, similar to stores labeling products with unique barcodes. The effort promises foolproof food inspection, improved border security and better defenses against disease-causing insects, among many other applications.

But the approach as currently practiced churns out some results as inaccurately as a supermarket checker scanning an apple and ringing it up as an orange, according to a new Brigham Young University (BYU) study.

The results are published online this week in the journal Proceedings of the National Academy of Sciences (PNAS). The researchers recommend specific quality control procedures to ensure that correct genes are captured.

"It's important to test any scientific tool because all have limits--some situations are more suited than others for barcode use," said Rick McCourt, program director in the National Science Foundation (NSF)'s Division of Environmental Biology, which funded the work. "This research could help clarify the answer to that question."

Organisms can be identified no matter what stage of life they are in. For example, larvae of malaria-carrying mosquitoes contain the same DNA as the adult version of the insect targeted for eradication. The portion of the gene selected as the universal marker by the barcoding movement is part of the genome found in an organism's mitochondria. But the BYU study showed the current techniques can mistakenly record instead the "broken" copy of the gene found in the nucleus of the organism's cells.

This non-functional copy can be similar enough for the barcoding technique to capture, but different enough to call it a unique species, which would be a mistake.

With the International Barcode of Life project seeking to build on the 400,000 species that have been "barcoded" to date, this goal warrants more careful execution, the BYU team says.

"To have that kind of data is hugely valuable, and the list of applications is endless and spans all of biology," said PNAS paper co-author Keith Crandall, a biologist at BYU. "But it all hinges on building an accurate database. Our study is a cautionary tale--if we're going to do it, let's do it right."

Proponents of DNA barcoding seek to establish a short genetic sequence as a way of identifying species in addition to traditional approaches based on external physical features.

Their aim is to create a giant library full of these sequences. Scientists foresee a future handheld device like a supermarket scanner--a machine that would sequence a DNA marker from an organism, then compare it with the known encyclopedia of life and spit out the species' name.

This new approach requires only part of a sample. A feather left behind by a bird struck by an airliner, for example, would be enough to indicate its species and clue officials how to prevent future collisions.

"Building a genetic library of all life is a great goal," said Song, "but we need to pay careful attention to the data that go into that library to make sure they are accurate."

"Scientists have been so preoccupied with creating a barcode of life, that they have not been careful in monitoring the accuracy of the underlying data," BYU scientist Michael Whiting said.

-NSF-

Media Contacts
Cheryl Dybas, NSF, (703) 292-7734, cdybas@nsf.gov
Michael Smart, BYU, (801) 372-4011, michael_smart@byu.edu

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2014, its budget is $7.2 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.

 Get News Updates by Email 

Useful NSF Web Sites:
NSF Home Page: http://www.nsf.gov
NSF News: http://www.nsf.gov/news/
For the News Media: http://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics: http://www.nsf.gov/statistics/
Awards Searches: http://www.nsf.gov/awardsearch/

 

Photo of scientist Hojun Song of Brigham Young University.
Scientist Hojun Song of Brigham Young University found that DNA barcoding is not always accurate.
Credit and Larger Version



Email this pagePrint this page
Back to Top of page