Cheetahs with stripes? Tabby cats with blotches? Researchers in the laboratory of Stanford geneticist Greg Barsh, MD, PhD, have pinpointed the cause of the unique coat patterns that give big and little cats their familiar periodic markings that allow even small children to distinguish a tiger from a cheetah. The research will be published tomorrow in Science. From our release:
The scientists found that the two felines share a biological mechanism responsible for both the elegant stripes on the tabby cat and the cheetah’s normally dappled coat. Dramatic changes to the normal patterns occur when this pathway is disrupted: The resulting house cat has swirled patches of color rather than orderly stripes, and the normally spotted cheetah sports thick, dark lines down its back.
“Mutation of a single gene causes stripes to become blotches, and spots to become stripes,” said [Barsh], emeritus professor of genetics and of pediatrics at Stanford and an investigator at the HudsonAlpha Institute.
The differences are so pronounced that biologists at first thought that cheetahs with the mutated gene belonged to an entirely different species. The rare animals became known as “king cheetahs,” while affected tabby cats received the less-regal moniker of “blotched.” (The more familiar, striped cat is known as a mackerel tabby.)
The Stanford researchers collaborated with colleagues at the National Cancer Institute and HudsonAlpha Institute for Biotechnology in Huntsville, Alabama to conduct the study on feral cats in Northern California and captive and wild cheetah populations in North America, South African and Namibia. The results have implications beyond natural history. Again from our release:
Barsh and his lab members have spent decades investigating how traditional laboratory animals such as mice develop specific coat colors. His previous work identified a variety of biologically important pathways that control more than just hair or skin color, and have been linked to brain degeneration, anemia and bone marrow failure. But laboratory mice don’t display the pattern variation seen in many mammals.
Photo by Greg Barsh