Scientists say they've found the gene that sets the common tabby cat pattern - stripes or blotches.
It's one of several genes that collaborate to create the distinctive design of a cat's coat, and it's the first of the pattern genes to be identified.
Cats with narrow stripes, the so-called "mackerel" pattern, have a working copy of the gene. But if a mutation turns the gene off, the cat ends up with the blotchy "classic" pattern, researchers reported online on Thursday in the journal, Science.
It's called "classic" because "cat lovers really like the blotched pattern", said one of the authors, Greg Barsh. He works at both Stanford University and the HudsonAlpha Institute of Biotechnology in Alabama.
The research team, which included scientists from the National Cancer Institute, examined DNA from wild cats in California to identify the gene.
They also found that a mutation in the same gene produces the blotches and stripes of the rare "king" cheetah, rather than the spots most cheetahs have.
Leslie Lyons, a cat geneticist who studies coat colour traits at the University of California, Davis, but didn't participate in the new work, agreed that the research has identified the tabby's stripes-versus-blotches gene. She noted that mysteries remain, like just what genetic machinery gives a tabby spots.
"The cat has not revealed all its mysteries yet," she said.