DNA Barcodes Reveal Secrets

DNA fingerprinting is an exciting new development in the field of genetics that is helping unmask a variety of hitherto unknown secrets. The new found scientific power to quickly "fingerprint" species via DNA is being deployed 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, among other applications across a wide array of public interests.

The explosion of creative new uses of DNA "barcoding" -- identifying species based on a snippet of DNA -- will occupy centre stage as 450 world experts convene at Australia's the University of Adelaide Nov. 28 to Dec. 3.

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. Other studies this year revealed unlisted ingredients in herbal tea bags.

Hot new applications include:

Substitute ingredients in herbal medicines

High demand is causing regular "adulteration or substitution of herbal drugs," barcoding experts have discovered.

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Indeed, notes Malaysian researcher Muhammad Sharir Abdul Rahman, one fraudster in his country treated rubber tree wood with quinine to give it a bitter taste similar to Eurycoma longifolia -- a traditional medicine for malaria, diabetes and other ailments.

A library of DNA barcodes for Malaysia's 1,200 plant species with potential medicinal value is in development, eventually offering "a quick one step detection kit" to reduce fraud in the lucrative herbal medicine industry, says Mr. Sharir.

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His concerns resonate in other countries around the true contents of certain brands of ginseng and other products.

DNA barcode libraries are under construction for the medicinal plants of several other nations as well, including South Africa, India and Nigeria.

Barcoding permafrost

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.



Source-Eurekalert