Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA barcoding in danger of 'ringing up' wrong species

26.08.2008
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 study. It was funded by the National Science Foundation and published in the prestigious Proceedings of the National Academy of Sciences.

With the International Barcode of Life project seeking $150 million to build on the 400,000 species that have been "barcoded" to date, this worthy 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 study co-author Keith Crandall, professor and chair of the Department of Biology 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. And organisms can be identified no matter what stage of life they are in – 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. It is often difficult and time-consuming to identify this type contamination, which could lead to overestimating the number of species in a sample by more than several hundred percent, according to the BYU study.

BYU scientist Hojun Song, a post-doctoral researcher working in the laboratory of Michael Whiting, professor of biology, was preparing a paper based on his genetic analysis of grasshoppers. He noted that his sequencing turned up many of these problematic "numts" (nuclear mitochondrial pseudogenes), as scientists call these bits of inactive genetic code. When Crandall saw the unpublished paper, he recognized similar results from an analysis of cave crayfish conducted by his doctoral student, Jennifer Buhay, and recommended the two teams collaborate. The result is the PNAS paper, on which Song is the lead author and Buhay and Whiting are also co-authors, that recommends specific quality control procedures to ensure that correct genes are captured.

"I recognize that some who do DNA barcoding may be upset by this study, but that is the nature of science," Song said. "Building a genetic library of all life is a great goal, but we need to be careful to pay attention to the data that go into that library to make sure they are accurate."

Song and Crandall hope that when funding agencies hand out grants to pursue projects such as the International Barcode of Life that applicants will be required to use the procedures identified in the new paper to avoid a large portion of the numts that might otherwise be unfiltered.

Michael Smart | EurekAlert!
Further information:
http://www.byu.edu

Further reports about: Barcode Contamination DNA DNA Barcoding Genetic barcoding genetic sequence genetic tag

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>