Was it a leopard or panther slinking by?
New DNA tool helps scientists identify wildlife species
Is the animal that is attacking the cattle on your farm a lion or a tiger? Is it a stray goat or a deer destroying your crop? Does the meat in your burger look suspicious?
For the first time such questions can be conclusively answered. All that's needed is a sample of the animal's blood, hair, saliva, skin, or fecal matter. Based on the DNA this provides, the animal's identity can be checked through a database of DNA samples. The accuracy is such that the test can distinguish between members of the same family - lion, panther, or tiger; deer or goat.
DNA fingerprinting technology, now an indispensable tool for law enforcement worldwide, was first used in India in 1989 by Lalji Singh, director of the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad. Then, last month, Dr. Singh led his team to make DNA fingerprinting a path-breaking tool for wildlife forensics.
The development is a boon for wildlife crime detection. Often poachers skin or hack up the animals they kill, leaving few pieces of their carcasses behind. Until now, Indian wildlife inspectors have depended on morphological features - large canines, for example, could mean a tiger or a panther - to identify the animals.
"These approaches are rarely effective in establishing the exact identity of mutilated biological samples, skinned carcasses, and tiny pieces of skin and meat commonly seized by the investigation agencies. Therefore it became very essential to develop a DNA-based approach, which could resolve the identity of such critical samples to the level of its family, genus, and species," says Singh.
With WITNess, Singh's new program, tin place, test results arrive within 32 hours of receipt of an animal sample. CCMB has entered into an agreement with a bioinformatics company here to create and automate a database to store the information the team gathers.
CCMB is no stranger to wildlife. In 2000, the Indian government entrusted it with the task of cloning endangered species like tigers, lions, and leopards. And in the past two years, CCMB has solved nearly 30 cases referred to it by India's Central Zoo Authority, the program's funding agency.
The most sensational case was from Chennai in the state of Tamil Nadu. Last year, a stray carnivore was believed to be walking in and out of the Chennai Zoo. Panic-stricken authorities closed the facility to the public. Finally, zoo officials got a sample of the beast's fecal matter and sent it to CCMB, which identified it as a leopard's. Zoo authorities laid a trap and caught the 10-year-old leopard, which lived in the vast forests nearby and visited the zoo when it was in heat.
CCMB currently has a database of 1,755 different animals, which it plans to increase to 25,000 this year and eventually to 50,000. DNA databases of different animals lodged in various research labs across the world are being sourced for this.
Is this number sufficient to establish the identity of any animal in nature's wide range of species? "Absolutely accurately, authentically, and scientifically," Singh says. This database will be in the public domain, he adds, as are the DNA databases the team is now accessing around the world.
The universal primer for wildlife DNA fingerprinting created by Singh's team looks at the part of an animal's DNA in the middle of its spectrum. This part changes from species to species and is referred to as the "signature" of the animal.
Singh says the research needed to arrive at this point was painstaking.
"The major challenge for us was to identify a fragment of the DNA which contains the species-specific signals in its nucleotide sequence. Another challenge was to develop a biological tool to decode this signature in a sample of unknown origin and further develop a database of such signatures ... so that it could be used for comparison while establishing the identity of unknown samples," he says.