The Tortie Point Siamese Cat

So, what is a tortie point Siamese cat? Most of us have heard of seal, chocolate, blue, lilac and even flame points, but torties?

A tortie (from tortoiseshell) point Siamese is a cat that has flecked or mottled points instead of solid ones, resembling the shell of a tortoise.

Tortie points come about through some complicated breeding which we'll get to shortly, but for starters, take a look at seal tortie point Yuki, below. As you can see, her mask is flecked and spotted with white.

This happens with other point colors too - in the tortie point versions, faces, noses, ears, legs, feet and tail are found in often unusual and beautiful mottled or spotted combinations of seal and red (or white), blue and cream, caramel and apricot.

What Makes a Tortie Point Siamese Cat? Tortie Genetics for Beginners

Bear with me, this might take some explaining!  And I'm not a geneticist, so, in very simple terms ...

Purebred seal, blue, chocolate and lilac, as well as the newer cinnamon, caramel and fawn point Siamese colors don't carry the orange or 'O' gene.

The gene that codes for orange effectively turns black coloring into ginger, in cats. Red, apricot and cream are all shades of ginger caused by the presence of the orange gene.

When a Siamese in one of the solid colors (seal, blue, chocolate, etc., that don't have the orange gene) is crossed with a cat that does have the orange gene, one of several things may happen. But first ...

Some Slightly More Advanced Genetics

If you know anything about genes, you'll know that they're carried on chromosomes. Females have paired XX chromosomes, males have XY chromosomes. The orange gene is only carried on the X chromosome.

A male cat only has one X chromosome, so if he inherits an orange gene it will change all his black or dark coloring (his points, in a Siamese cat's case) to a shade of ginger. So a male cat only needs to inherit one orange gene in order to give him red, apricot or cream points.

A female cat, on the other hand, having two X chromosomes, needs to inherit orange genes on both chromosomes in order to give her totally red or apricot or cream points.

The Cause of the Tortoiseshell Effect

If a female cat inherits the orange gene on only one of her chromosomes, it will only change half her pigment to one of the red shades. The other half will remain as it would have been without the orange gene.

So the tortie point Siamese comes about because half of the points change color; in the case of seal, chocolate or cinnamon points, to red; blue and fawn points to cream, and caramel points to apricot.

(This also explains why tortoiseshell cats are almost always female – a tortoiseshell male cat would be very, very rare – and a genetic abnormality).

The Different Variations of Tortie Point

There are seven different varieties of tortie point Siamese cat. These are described by the Governing Council of the Cat Fancy (UK) as follows:

Seal tortie
Points: Seal brown with shades of red
Body: Cream. In kittens the body colour may be muddy fawn

Blue tortie
Points: Light blue with shades of cool toned cream
Body: Glacial white

Chocolate tortie
Points: Milk chocolate with shades of red
Body: Ivory

Lilac tortie
Points: Pinkish grey with shades of cool toned cream
Body: Off-white (magnolia)

Cinnamon tortie
Points: Warm cinnamon brown with shades of red
Body: Ivory

Caramel tortie
Points: Brownish grey with shades of apricot
Body: Off-white (magnolia)

Fawn tortie
Points: Warm pale rosy mushroom with shades of cream
Body: Off-white (magnolia)

So Now You Know

And the next time you see a Siamese tortie point cat, you'll be able to impress your friends with your new-found knowledge, both of cats, and genetics!

Related Pages

• Red, apricot and cream point Siamese
  
• Flame point Siamese
• Siamese cat colors
  

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