As any cat lover knows, distinct patterns of dark and light hair color are apparent not only in housecats but also in their wild relatives, from cheetahs to tigers to snow leopards. Researchers at the HudsonAlpha Institute for Biotechnology and Stanford University, along with colleagues around the world, today reported new genetic findings that help to understand the molecular basis of these patterns in all felines.
A so-called "mackerel tabby" cat has dark tiger stripes, which coalesce into swirls and blotches in a "classic tabby" cat. Like other periodic natural patterns such as stripes on a zebra or spinal bones and vertebra, the origin of these repetitive structures is an unsolved mystery. "Until now, there's been no obvious biological explanation for cheetah spots or the stripes on tigers, zebras or even the ordinary house cat," said Gregory Barsh, M.D., Ph.D., faculty investigator at HudsonAlpha and emeritus professor of genetics at Stanford University, one of the senior authors of the study.
When comparing sequence differences between striped and blotched domestic cats, the researchers saw the evidence pointed to a gene that they named Taqpep. Blotched cats had specific mutations in both copies of this gene, while striped cats did not. Remarkably, the rare "king cheetah," once thought to be a unique species because of an unusual striped pattern rather than regular spots, also carried a mutation in Taqpep.
The team then went on to ask how spots, stripes or blotches form in the first place. "Somehow, cells in the black stripes know they are in a black stripe and remember that fact throughout the organism's life," said Barsh. "We were curious about what's happening at the boundary between light and dark stripes and spots. How do these spots know to grow with an animal?"
Their examination of genes expressed in dark versus light hair cells revealed that patterned markings are due to variations in another gene, Edn3, bein
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HudsonAlpha Institute for Biotechnology