Genetics: Tiger genome reveals predatory adaptations

The first whole genome sequence of the Amur Tiger and genomic sequences from the white Bengal tiger, African lion, white African lion and snow leopard are reported this week in Nature Communications. A comparative analysis highlights genomic signatures that are consistent with both a carnivorous diet and muscle strength. The sequences provide a valuable resource for investigating the genetic diversity and conservation of big cats.

The tiger, Panthera tigris, is the world’s largest felid species and is predicted to soon become extinct if effective conservation measures are not deployed. The preservation of wild tiger populations, currently estimated to total less than 4,000 individuals, is now a major goal of animal conservationists. Jong Bhak and colleagues present the first tiger genome sequence assembly, utilizing the DNA of a nine-year-old tiger from Everland Zoo, Korea, and sequence four additional Panthera genomes in order to better understand the predatory adaptations and evolution of big cats.

The team identify 1,376 big-cat specific genes indicative of a carnivorous diet, through a comparative analysis of genomes including tiger, human, dog and mouse, and provide evidence for the rapid evolution of genes involved in muscle contraction and the actin cytoskeleton. The team also identify two candidate genes that may have been important in the snow leopard’s adaptation to high altitudes and pinpoint a potential coat colour gene in the white lion.