September 18, 2013
Genome Sequencing Of Big Cats Complete
April Flowers for redOrbit.com - Your Universe Online
In conservation efforts aimed at protecting endangered species, a group of international scientists has mapped the genome of the Siberian, or Amur, tiger. The findings, published in Nature Communications, reveal clues to how the big cat evolved to become a top predator with a carnivorous diet and superior muscle strength.
According to National Geographic, the Siberian tiger is the largest tiger subspecies. The animals weigh as much as 660 pounds and can grow up to ten feet in length. Currently only an approximate 450 Siberian tigers exist in the wild, with an estimated 4,000 tigers total remaining in their natural habitats.
"We looked at this very large tiger first to see what made it distinctive from other cats," said genome expert Jong Bhak of South Korea's Personal Genomics Institute in Suwon. Bhak was part of the team lead by Yun Sung Cho at the Personal Genomics Institute, Genome Research Foundation that sequenced the genome of Taegeuk, a nine-year old male Siberian tiger from Everland Zoo in South Korea.
BBC News reports that the team also sequenced four other large cats - the (African) lion, snow leopard, white (Bengal) tiger and white (African) lion - enabling them to compare how the genes matched up in different members of the cat family.
"Genetically all the cats are very close, so we need close genetic mapping to find the small differences that make them distinct," Bhak told Dan Vergano of National Geographic.
Beyond superior muscle strength and a need for lean meat, the genetic analysis gave clues to how the white lion gained its pale coat and how the snow leopard adapted to the snowy mountain ranges.
Across the study species, however, the cat family seems to rely on a narrow set of 1,376 genes linked to strong muscle fibers and digestion of protein. The study suggests that the genes likely originated in large part with the earliest common ancestor of big felines some 11 million years ago.
"I take this to indicate that [big cats] have evolved to fill a very particular carnivorous niche in the environment that is predicated on the advantages in hunting these genes provide," Bhak told Vergano.
"Our tiger reference genome can be used as the basis for comparing all the tigers in the world, so that we know the genetic diversity of tigers," he told BBC reporter Helen Briggs.
"And we can actually have a plan of how we can breed tigers effectively [in zoos] to save the genetic diversity."
Until this study, the only cat genome to have been mapped was the domestic cat, which shares 96 percent of its genes with the big cats.
"Tigers are just a big domestic cat," he added. "They're probably much closer than we thought."
Carlos Driscoll, World Wildlife Fund chairman in conservation genetics at the Wildlife Institute of India, Chandrabani, said the paper was a watershed in conservation as it marks the first non-domestic cat genome to be sequenced.
"This brings the age of genomics to the conservation of these species, which are an umbrella for the conservation of many other animals and habitats," Driscoll told BBC's Briggs. "This sets a new standard for the conservation community to follow."