DNA Barcoding

DNA barcoding was invented by Paul Hebert of the University of Guelph, in Ontario, Canada, in 2003. His idea was to generate a unique identification tag for each species based on a short stretch of DNA. Separating species would then be a simple task of sequencing this tiny bit of DNA. Dr. Hebert proposed part of a gene called cytochrome oxidase I (COI) as suitable to the task. All animals have it. It seems to vary enough, but not too much, to act as a reliable marker. And it is easily extracted , because it is one of a handful of genes found outside the cell nucleus in structures called mitochondria. Barcoding has taken off rapidly since Dr. Hebert invented it. When the idea was proposed, it was expected to be a boon to taxonomists trying to name the world's millions of species. It has, however, proved to have a far wider range of uses than the mere academic -- most promisingly in the realm of public health. One health-related project is the Mosquito Barcoding Initiative being run by Yvonne-Marie Linton of the Natural History Museum in London. This aims to barcode 80% of the world's mosquitoes within the next two years to help control mosquito-borne diseases. Mosquitoes are responsible for half a billion malaria infections and 1m deaths every year. They also transmit devastating diseases such as yellow fever, West Nile fever, and dengue. However, efforts to control them are consistently undermined by the difficulty and expense of identifying mosquitoes -- of which there are at least 3,500 species, many of them hard to tell apart.