The Genetics Behind Venus, the Mysterious Two-Faced Cat

A cat named Venus is one of the most famous felines on the planet. The three-year-old torty has her own Facebook page and has collected more than a million views on YouTube, in addition to making appearances on the Today Show and in other news venues. The reason behind Venus’ fame? Her striking two-face markings: half black-with-yellow eye, half orange-with-blue-eye.

National Geographic investigates the possible genetic anomalies that contribute to Venus’ unique look. Cat geneticist Leslie Lyons of the University of California, Davis, told NatGeo that she’s never seen a kitty quite like Venus. “She is extremely, extremely rare,” she said.

Venus is not necessarily a chimera, or an animal whose cells contain two sets of DNA caused when two embryos fuse together during development. But Lyons said to find out for sure whether or not Venus is a chimera, she’d need to perform genetic testing.

If the cat is no chimera, what would explain her striking pattern? “Absolute luck,” Lyons told NatGeo. For example, the black coloration could have randomly activated in all of the cells on one side of her adorable kitty face, while cells coding for orange coloration kicked in on the other side. The two patches then met in the middle as she developed in the womb.

But it’s Venus’ single blue eye, Lyons points out, is the real mystery. Cats usually sport yellow or green eyes, while those with baby blues tend to have Siamese heritage and include predominantly white coats. Venus, however, only has a small white patch on her chest, not enough to explain the blue eye.

Genetically, Lyons admits, “She is a bit of a mystery.”

Check out Venus in her natural habitat:

More from Smithsonian.com:

Cats as Pets and Predators  
A Brief History of House Cats 

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.