[NEW DELHI] Indian scientists have developed a genetic test that can distinguish between animal species, allowing for simpler identification of samples when individuals are being prosecuted for wildlife offences, and the more accurate identification of confiscated biological material.
At present, investigators have to use either physical features or biochemical tests to identify the remains of animals suspected of having been killed by poachers. But both methods have limitations, especially when a skinned carcass or fragments of skin and meat may be all that is left of an animal.
Now scientists at the Hyderabad-based Centre for Cellular and Molecular Biology (CCMB) have developed a genetic test to detect exactly which animal species the remains belong to.
“Without knowing the history of the forensic sample, the DNA-based test can establish whether a drop of blood or small piece of meat belongs to a human or an animal, and if an animal, to which species,” says CCMB Director Lalji Singh.
The major challenge for CCMB scientists was to identify a fragment of DNA that is present in all animals, but not in humans. They also needed to find a second DNA fragment that was unique to each animal species, in order to allow precise identification.
After two years of work, the CCMB team has identified such fragments on a gene called cytochrome b that is present in the mitochondria – the energy generating components of cells. The fragment has a small section that is common to all animals. Additionally, it contains species-specific proteins that serve as a molecular “signatures” for the species, says Singh.
Once these proteins have been isolated from a sample of unknown origins, they can be compared against a database containing “signatures” of 2,000 animal species to establish the identity of the animal from which they have been taken.
“The technique has the potential to replace the need for expensive laboratory set-ups in which vast collections of morphological and biochemical markers are maintained to provide scientific evidence of wildlife offences,” according to a recent report by Singh and colleague Sunil Verma in the journal Molecular Ecology Notes.
The researchers say that the CCMB has already solved 25 cases forwarded by wildlife curators and crime investigation agencies by using their tests.