Millennium Post

Decoding predatory genes

TIGERS have evolved to become one of the most ferocious predators in the cat family. At the genetic level, all big cats are quite close. But it is the small differences in the genes that distinguish them from each other. These are the findings of a latest study which has, for the first time, mapped the?whole genome sequence of the Amur (Siberian) tiger and compared it with that of the domestic cat, white Bengal tiger, African lion, white African lion and snow leopard.

In the cat family, so far only the genome of the domestic cat had been mapped. For tigers, till now, most of the genetic research was concentrated on traditional sequencing approaches, mostly limited to non-functional DNAs. For the first time, a database of functional genes has been created. The?mapping was conducted on the genes of a nine-year-old captive male Amur tiger at the Genome Research Foundation in Suwon, South Korea. It showed how tigers gained their extensive muscle strength, the metabolism to digest large quantities of meat and a keen sense of smell which helps them hunt, find mate and demarcate territories. The mapping shows that the big cat is genetically very similar to the domestic one. ‘The tiger genome sequence shows 95.6 per cent similarity to the domestic cat from which it diverged approximately 10.8 million years ago,’ says the study published in Nature Communications on September 17. The similarity between humans and gorillas that diverged around 8.8 million years ago is 94.8 per cent.

To understand what makes big cats distinct from each other, the study additionally sequenced genomes of a white Bengal tiger, an African lion and an Asian snow leopard. Two mutations were identified by the scientists which are likely to be responsible for the snow leopard’s adaptation to high altitudes and the white fur on white African lions. Scientists believe genome mapping of the big cats can be a?breakthrough in conservation efforts. ‘Our data from tigers, lions and snow leopards can provide a rich and diverse genome resource that could be used in future studies of conservation and population genomics so that the genetic underpinnings of local adaptation and potential inbreeding and/or out-breeding in wild and captive populations can be illuminated, and thereby help ensure the future survival of these majestic species,’ claims the study.

K Praveen Karanth, associate professor at the Centre for Ecological Sciences, Indian Institute of
Science, Bengaluru, says the study will help scientists in designing new markers to study genetic diversity among tigers. Down to Earth
Next Story
Share it