Q How come my cat's whiskers are striped, with bands of white and brown on each one? How does the pigment change like that as a single whisker grows?
A This banding pattern is typically associated with the agouti gene, which also produces banding in ordinary fur in some cats, said Dr Robert A. Grahn of the Veterinary Genetics Laboratory at the University of California, Davis.
But cat whiskers do not seem to follow the same pigmentation patterns observed in other hair types.
In regular fur, the agouti gene controls the production of granules that carry pigment, speeding it up and slowing it down so that an individual strand winds up with light and dark bands. This produces so-called ticked coats, seen in many tabbies and Abyssinian cats.
The difference in pigmentation patterns for whiskers is likely due to more complicated development patterns and physiology, he said. The location of the whisker root is deep in the skin and is associated with a special blood supply and sensory nerves.
This structure allows a cat to use its whiskers to sense things, like clearance in tight places and even slight breezes.
Dr Grahn said he had not personally observed the described banding pattern in whiskers, but had not looked for it. He said he had seen whiskers in which the pigment switches part way through the growth cycle, as well as cats with both black and white whiskers.
"In the end, the genetics underlying the pigmentation of cat whiskers, while interesting, has not garnered significant research efforts," Dr Grahn said.