An international team of genome scientists has mapped the whole genome sequence of big cats, including tiger, lion and snow leopard, with the purpose of investigating the genetic diversity and conservation of big cats.

The research team, led by scientists in South Korea, in collaboration with colleagues from China, the United States, India, Mongolia, South Africa and other countries, published the latest findings in the September issue of Nature Communications.

Yun Sung Cho, the first author of this published paper, and his colleagues presented the first tiger genome sequence assembly, utilizing the DNA of a nine-year old Amur tiger from Everland Zoo, South Korea.

The team identified 1,376 big-cat specific genes to reveal how big cats evolved into top predators with extraordinary muscle strength and a carnivorous diet.

"The most important academic reason of choosing tiger (big cat) genome was to experiment a new genomics approach called 'close but distinct species genomics'," Jong Bhak of South Korea's Personal Genomics Institute in Suwon, one of the lead scientists of the research, told Xinhua.

Bhak said cat species are genetically quite close but they exhibit distinct phenotypes, namely outward traits. Scientists have mapped the genome of cat in 2010. However, the quality of the cat reference was not high enough to find big cat specific variations.

For comparison, the team sequenced the DNA of close species and subspecies including the (African) lion, snow leopard, white ( Bengal) tiger and white (African) lion.

The team identified two candidate genetic alterations that related to the snow leopard's adaptation to high altitudes and pinpoint a potential coat color gene in the white lion.

"Tiger reference genome can enable all the tigers in the world to compare with it in the future. We can have a very accurate set of tiger lineage and diversity map," said Bhak, adding that with these results, researchers and zoo scientists can choose better mates for breeding tigers and monitor wild tiger genetic diversity much more accurately.

Bhak said as he and other South Korea's scientists are trying to reintroduce tigers into the Korean Peninsula, these genome data can be applied to selecting individual tigers with high genetic diversity.

The team are now trying to acquire all the big cat genomes especially American big cat samples to sequence and make a whole set of cat genome with known clear phenotypes.

"We want to make this information available and open freely to all researchers interested in and focused on conservation research. This is our contribution to the global conservation efforts for this beautiful species," Bhak said.

The sequence of other rare species are also their targets. They are working on whale genomes now. In 2009, Jong Bhak and his colleagues had sequenced the first Korean human genome.