Gene mutations cause beautiful colors for torties, calicos

Posted October 02, 2019 11:00 pm

By Mary Hayashi The Buddy Foundation

Gemma is a female tortie, who was very shy when she first arrived at Buddy. She has become more outgoing and willing to play and eat treats from your hand. Courtesy of The Buddy Foundation

When I was last at the shelter, I noticed the beautiful array of coat colors and patters on our felines. I wondered what change in genetic makeup determines a predisposition for a tortoiseshell cat or a tortoiseshell cat with white (a tri-colored coat), otherwise termed calico?

Tortoiseshell markings (tortie) can be found in specific breeds of cats, as can tortie with white.

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

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. It 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 gene, she will be tortoise. When the second X is inactivated, the black color appears.

What next determines the pattern of the coats 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 skin'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.

Tortie and calico felines 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.

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

Upcoming

• Join The Buddy Foundation at Bowling for Buddy from 1:30-4:30 p.m. Sunday, Nov. 10, at Arlington Lanes, 3435 N. Kennicott Ave., in Arlington Heights. Admission is $30 in advance for adults ($35 at the door) and $15 for children ages 12 and younger. Admission includes two games of bowling, shoe rental, pizza, salad, dessert and soda. Proceeds will benefit Buddy's animals. To register, visit www.thebuddyfoundation.org or call (847) 290-5806.

• The Buddy Foundation, 65 W. Seegers Road, Arlington Heights, is an all-volunteer, nonprofit organization with all funds directly assisting its animals. Its mission is to provide immediate safety and care to stray and abandoned cats and dogs. Call (847) 290-5806 or visit www.thebuddyfoundation.org.

Ginger is a small female tortie with a tan chest. She was found at a 7-11 near some apartments. She is a shy, little girl and can frequently be found in the corners or hiding under some blankets on the couch. When she is out she can be quite playful and loves chasing after little coiled plastic springs. In the afternoon, when the shelter has quieted down, she can occasionally be seen out playing with the other cats. Courtesy of The Buddy Foundation

Patches is a beautiful female golden tortie. She was found as a kitten and brought to the shelter. As a kitten, she was very shy around people. It took her quite a while to overcome that, but now that she is in one of adult cat rooms she has become much less shy. She can frequently be found on the cat trees or sometimes looking out the window at the birds. You might have to approach her slowly or with a treat before she will let you pet her. Courtesy of The Buddy Foundation

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