Quack medicines and what eats what in nature revealed by DNA barcodesPublished On: Mon, Nov 28th, 2011 | Genomics | By BioNews
Scientists have deployed the newfound scientific power to quickly “fingerprint” species via DNA to unmask quack herbal medicines, reveal types of ancient Arctic life frozen in permafrost, expose what eats what in nature, and halt agricultural and forestry pests at borders.
DNA barcode technology has already sparked US Congressional hearings by exposing widespread “fish fraud”, — mislabelling cheap fish as more desirable and expensive species like tuna or snapper.
From the woolly rhino to plants and mushrooms, scientists using DNA are deciphering what lived in the ancient Arctic environment, creating new insights into climate change in the process.
“DNA barcoding” analyses of cylinders of sediment cored from Arctic permafrost ranging in age from 10,000 to several hundred thousand years have shed light on past animal and fungal distributions and allowed researchers to infer which plant species likely co-existed.
DNA analyses of permafrost sediment 15,000 to 30,000 years old from northeastern Siberia revealed a grassland steppe plain during the glacial period supporting a diverse mammal community, including bison, moose and the DNA of the rare woolly rhino, the first ever found in permafrost sediments.
“In the Arctic, fossils are scarce and time-consuming to find and analyze. However, DNA is one tough molecule. It had to be in order to serve its purpose the last billion years and more. Incredibly, it can linger in soil for tens of thousands of years and stay relatively intact,” Eva Bellemain, lead researcher from the University of Oslo, said.
The technology can even distinguish species contained in the gut or dung of animals, revealing what eats what. University of Adelaide researcher Hugh Cross, for example, will detail his investigation into the diet of Australia’s fast-growing, 1 million-strong population of wild camels, which severely impact the country”s ecology.
Introduced in the 1800s as pack animals, Australia’s wild camels eat an estimated 80 percent of available plant species in their range.
“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,” David Schindel, Executive Secretary of the CBOL, said.
Until now, border inspection to keep agricultural pests, disease-carrying insects and invasive species from entering a country has been a hit-and-miss effort. Barcoding offers a tool to get same-day answers for accepting or rejecting imports, an issue of acute economic importance to Australia and New Zealand.
With European Union funding, a consortium of 20 universities, research institutes, and other organizations are partners in Project QboL, developing a library of DNA barcodes to help quickly identify common invasive organisms that authorities want to stop at national borders.
With the new DNA barcode tool, inspectors can more easily and surely identify and thus prevent the entry of invading pests including bacteria, fungi, fruit flies, other insects, nematodes, viruses, plants and other organisms. Trade of timber cut from endangered species may also be slowed with barcodes to identify wood and lumber products.
“From tea to tuna, DNA identification is entering everyday life,” Jesse Ausubel, chair of the International Barcode of Life (iBOL) initiative, said.
A number of other purposes for which the researchers intend to use the technique are selecting the barcode region for fungi, survey long-term population trends by assembling barcode libraries for all bees and other important pollinators and assessing water quality.
The study will be presented at experts convene at Australia’s the University of Adelaide.