At this point it's just an interesting hypothesis, but it's possible that understanding cat coloration could help scientists understand resistance to infectious diseases.
Here's the connection. Stephen O'Brien and colleagues at a variety of institutions including the Hudson Alpha Institute for Biotechnology in Huntsville, Ala., and Stanford University in California have worked out some of the genetic pathways that explain why "some cats are spotted, some cats have stripes, some cats have what we call blotches, and other cats don't have any of that, they just have a black or a lion-like color," says O'Brien.
They spell out the explanation in the latest issue of Science.
O'Brien says different lineages of cat have the same kinds of coloration, but they got them in unique ways. The genetic variants that determine those patterns come from different mutations in the same genes.
When geneticists see that kind of pattern of mutations over time, they figure those genes must be doing something that confers an important survival advantage because they stick around. That's evolution.
Now, it's possible that the advantage is simply camouflage to avoid predators or stalk prey, but O'Brien believes something else may be going on.
"Many of the genes involved in coat color sit on the surface of cells," he says. "Viruses are always looking for things to jump on that can allow them to stick and then invade a cell." No one has explicitly made the connection with the cat coloration gene, but they're in the right place.
There are reported examples of skin pigment genes playing a role in response to invading organisms. "Melanin plays an evolutionary ancient role in insect immunity to malaria," writes Michael Waisberg of the National Institute of Allergy and Infectious Disease in a recent article, although his research shows that melanin does not have a similar protective role for mice.
So maybe, maybe, maybe understanding the genes involved in cat coloration will tell us something someday about human infectious diseases.