Meet Venus, currently the most famous cat in the world.
The 3-year-old tortoiseshell has her own Facebook page, a youtube video that has been viewed over a million times, and appeared on the Today Show last week. One look at this cat and it’s easy to see why: one half of her is solid black with a green eye, and the other half is orange tabby-striped with a blue eye.
A professor at the University of California in Davis, Leslie Lyons, who studies the genetics of domestic cats, has stated that she’s, “Never seen a cat exactly like Venus. She is extremely, extremely rare, but you can explain and understand it.”
Many articles about Venus refer to her as a “chimera.” A feline chimera is a cat whose cells contain two types of DNA, caused when two embryos fuse together. Among cats, “chimeras are really not all that rare,” Lyons said. In fact, most male tortoiseshell cats are chimeras. The distinctively mottled orange and black coat is a sign that the male cat has an extra X chromosome. This is because, in domestic cats, fur color is linked with the sex chromosomes (X and Y for male, and X and X for female.) So female cats, already having two X chromosomes, can have the tortoiseshell coat without the extra X chromosome. That means Venus is not necessarily a chimera.
“To find out would require genetic testing”, said Lyons. “With samples of skin from each side of the cat,”we can do a DNA fingerprint, and the DNA from one side of the body should be different than the other, “ if Venus is a true Chimera Cat, that is.
If Venus isn’t actually a chimera, then what would explain her amazing face?
“Absolute luck,” Lyons said. One theory is that perhaps the black coloration was randomly activated in all the cells on one side of her face, while the orange coloration was activated on the other, and the two patches met at the midline of her body as she developed.
Cat fanciers who are transfixed by Venus’s split face may be missing the real story: her single blue eye. Cat eyes are typically green or yellow, not blue. A blue-eyed cat is typically a Siamese or else a cat with “a lot of white on them,” she explained. Venus appears to have only a white patch on her chest, which to Lyons is not enough to explain the blue eye.
“She is a bit of a mystery,” and one fascinating house cat.
Happy Caturday, everybody