Torties’ beautiful markings are about the genes

When I was last at the shelter, I noticed the beautiful array of coat colors and patterns on our felines.

I wondered what change in genetic makeup determines a predisposition for a tortoise shell or a tortoise shell with white (a tri-colored coat), otherwise termed calico?

I am referring to coat markings, not a specific breed of cat. Tortoise shell markings (tortie) can be found in specific breeds of cats, as can tortie with white.

Torties are usually felines that have brindled, bicolored coats wherein the colors are intricately intermingled. Typically, they will not have any white and will be less patchy than a tortie with white, also known as calico.

Tortie and calico coats result from a combination of genetic and developmental factors in the embryo. The formation of red and black coloration in a female is called X chromosome inactivation. The O gene represents red pigmentation, which is carried by the X chromosome.

If a female has two O genes, she will be red. On the other hand, if she only inherits one O she will be tortoise. When the second X is inactivated, the black color appears.

What next determines the pattern of the coat for brindled or patchy? Pigment colored genes that arrive early usually produce brindle because they have more time to interact with each other. If the X inactivation occurs later, the brindle will be more intricate because the cells have less time to interact and less room to multiply.

The cells have less time to compete against each other, if you will. This can cause a ticking pattern to the fur. Ticking occurs when each hair can have both colors. A good example of a breed of ticked feline is the Abyssinian. They are tri-ticked.

In tortie-with-white felines another genetic factor comes into play. A spotting gene produces white, unpigmented patches by delaying pigment color to the sink’s surface. The later the pigment migration, the more likely our feline will be patched with significant amounts of white fur.

In an extreme case, a feline may not have any pigment to its skin. In that instance, we have a totally white animal, but not an albino.

Torties and calicos also come in an array of color combinations such as cream, blue, lilac and fawn. These are all lighter shades. The dilution genes are responsible for these lighter colorations.

Torties and calicos in general earn their spots from a series of gene mutations. That is just why they are so special.

If I had to offer some generalizations on torties and calicos based on my own household, I would say the darker the more vocal, closer to an Oriental or Siamese meow, and perhaps more temperamental.

The blues and creams, if not Oriental-looking, seem to be very affectionate. For sure, the safest generalization about blues and creams: they are very showy and rarer than the darker varieties.

Today’s adoptables are both of the dilute or blue coloration, so please meet Ashley and Cherbert.

AdoptablesAshley is a 3-year-old blue calico that has a large amount of white mixed in with her patching. This girl was found roaming the streets. When she was found, her fur was not the beautiful white you see now. She was dirty and dingy. She was taken to a facility (not Buddy, to await her fate). Once we learned her days were numbered, Buddy took her in. She is sweet and seeks attention. She likes other felines except when they want to steal her top spot on the cat tree, but she does grudgingly surrender.Cherbert is a blue cream tortoise with cream markings on the tips of her paws. She is sweet and elegant. She is the perfect example of the rarer dilute tortoise with cream. If you like this coloration and personality, you need to snatch up this 2-year-old youngster fast. We will not have this stunner at the shelter long.Did You Know?June is Adopt-A-Shelter Cat Month nationwide. If you have been thinking about adopting, come out and adopt this month so we can put as many of our cats into loving homes this month.Anniversary Open HouseOn Saturday, June 23, help us celebrate our fourth anniversary as a physical building at 65 W. Seegers Road in Arlington Heights. We will serve light refreshments and snacks. This is the perfect time to take home your new feline family member.Ÿ Contact The Buddy Foundation at (847) 290-5806; visit us at 65 W. Seegers Road, Arlington Heights; or online at thebuddyfoundation.org. 36492433Cherbert