By Dr. Becker
Attention cat parents and guardians!
Whether you share your life with Madame Meow or Admiral Snuggles, your little fluff muffin is a real tiger at heart. In fact, your favorite feline shares over 95 percent of his or her DNA with tigers, despite having split apart on the evolutionary tree almost 11 million years ago.
This fascinating detail was among the recent discoveries of a team of researchers from China and the Republic of Korea who sequenced the genomes of tigers, lions and snow leopards as part of conservation efforts to save these magnificent animals from extinction. Their findings were published in September in the journal Nature Communications.1
Genome Sequencing of Big Cats Provides Fascinating Insights
In the study, geneticists sequenced the whole genome of a 9 year-old Amur tiger, also known as the Siberian tiger, and compared it to the genomes of a white Bengal tiger, an African lion, a white African lion, and a snow leopard.
Beyond the discovery that Siberian tigers share 95.6 percent of their DNA with housecats, the sequencing also revealed that:
- In big cats, several genes are altered in the metabolic pathways linked to protein digestion and metabolism. Those adaptations, which evolved over tens of millions of years, are thought to be what allows felines, as obligate carnivores, to digest and live solely on a diet of animal meat.
- Big cats also have a number of gene mutations that explain their incredibly powerful, fast-acting muscles.
- The snow leopard had unique amino-acid changes in certain genes that may contribute to its ability to adapt to high altitudes.
- The genes associated with muscle strength, energy metabolism, and sensory nerves -- including those involved in visual acuity and sense of smell -- seem to be undergoing rapid evolution in the tiger.
- White lions possess a variant in the TYR gene, which is the gene related with white coat color in domestic cats, as well as a form of albinism in humans.
Only 3,000 to 4,000 Tigers Remain in the Wild
Despite their well-earned reputation for ferociousness, in today’s world big cats are arguably more endangered than they are dangerous. Habitat loss, poaching and shrinking food supplies have put tigers near the top of the world’s most endangered species list. There are thought to be only 3,000 to 4,000 tigers remaining in the wild.
The new information revealed by genome sequencing should help conservation efforts by giving scientists a tool to measure genetic diversity in tiger populations in the wild. Genome sequencing reveals whether the big cats are inbreeding, which puts them at even greater risk. According to Jong Bhak, a geneticist at the Personal Genomics Institute in South Korea, “If their population diversity is very low, then one flu virus can kill a lot of them quickly, because they have the same genetic makeup.”
If this is the case, scientists can make plans to introduce fresh blood into the population to make it more resilient. The information can also be used by captive breeding programs in selecting animals for mating that aren’t closely related.