As DNA “barcoding” technology becomes, quicker, cheaper and easier to develop, it is expanding rapidly into many areas from uncovering frauds such as mislabelled fish and unlisted ingredients in quack herbal medicines, to revealing ancient life-forms frozen in the Arctic permafrost, and preventing unwanted agricultural and forestry insect pests from crossing borders.
Such applications, and many others in what is being described as a worldwide explosion in the use of DNA barcoding, where the tiniest to the largest species can be identified from a snippet of DNA, will occupy centre stage when 450 world experts gather for the Fourth International Barcode of Life conference at the University of Adelaide in Australia from Monday 28 November to Saturday 3 December. The conference organizer is David Schindel, Executive Secretary of the Consortium for the Barcode of Life (CBOL). He is based at the Smithsonian Institution, Washington, DC.
DNA barcoding technology hit the headlines and triggered Congressional hearings in the US when it was used to unmask widespread “fish fraud” where cheap fish was being labelled as more expensive tuna, snapper and other species. And other studies have also reported that DNA barcoding helped identify unlisted ingredients in herbal tea bags.
Other interesting new applications expected to be discussed at the conference include:
For instance one report notes DNA barcoding helped uncover how a Malaysian fraudster was treating rubber tree wood with quinine to give it a bitter taste similar to to Eurycoma longifolia, a traditional medicine for malaria, diabetes and other illnesses.
Researcher Muhammad Sharir Abdul Rahman says they are developing a “one step detection kit” that can quickly scan the DNA barcode from a library of Malaysia’s 1,200 plant species with potential medicinal value, including ginseng. DNA barcode libraries are also being developed for of medicinal plants in other countries such as Nigeria, India and South Africa.
From wooly rhinos to mushrooms and plants, we are beginning to discover what organisms large and small lived in the ancient Arctic environment.
Scientists are analyzing cylinders of sediment frozen 10,000 to hundreds of thousands of years ago and using DNA barcoding to identify distributions of past animal and fungal species. Such information helps us also learn more about what influences climate change.
University of Oslo-based researcher Eva Bellemain, told the press:
DNA is one tough molecule” that can “linger in soil for tens of thousands of years and stay relatively intact”.
DNA barcoding can even distinguish species contained in the gut and dung of animals. Hugh Cross, a researcher at the University of Adelaide is using the technology to conduct a detailed investigation into the diet of Australia’s fast-growing population of wild camels, now thought to be one million strong and set to make a significant, and possibly severe, impact on the country’s ecology.
The wild camels, descendants of pack animals introduced in the 19th century, eat around 80% of the plant species they come across.
Schindel told the press that:
“Biologists used to sit and wait and watch to learn how food webs work in Nature and what happens when they collapse. Now they can process stomach contents and dung samples to get the complete picture in a few hours”.
Until recently, trying to stop disease-carrying insects and invasive species from getting into a country was a bit of a hit and miss effort, but DNA barcoding offers a way to get almost instant answers so imports can be accepted or rejected.
With help of funds from the European Union, a consortium of 20 academic centres and other organizations have formed the QBoL (Quarantine Barcode of Life, www.qbol.org) project which is developing a library of DNA barcodes so that the authorities can quickly identify the more common invasive organisms and stop them coming into the country. The library will include DNA barcodes for bacteria, fungi, fruit flies, nematodes, viruses, plants and other species.
DNA barcoding will also help reduce trade in timber produced from felling endangered tree species.
These are just some of the hundreds of topics that will be discussed in Adelaide, which will also include: identifying the species and prey of the African tsetse fly and other disease-carrying insects from DNA barcodes of their stomach contents; assessing the global status of bees and other pollinators; barcoding species of the ornamental fish trade; assessing water quality; and identifying indoor fungi that cause human health problems.
Schindel said:
“Like Google and Wikipedia, DNA barcoding scarcely existed a decade ago, and now we are a vibrant community built on 21st century scientific tools.”
“DNA barcoding is the express lane to solving many of Nature’s mysteries relevant to a spectrum of national interests,” he added.
As an example of how fast this field is growing, consider that in 2005, the University of Guelph in Canada housed 33,000 records covering 12,700 species in the Barcode of Life Data Systems (BOLD). It now houses some 1.4 million records covering about 167,000 known and provisional species: a 40-fold increase in 6 years.
For more information on the conference and to see its agenda click here.
Written by Catharine Paddock PhD