Cat coat: Siamese, point coloration, and albino cats!
What's the color of your cat? To answer this question, in this fourth article in my series on cat coats I'm going to talk about the different point colorations, their genetics, and the differences with the Siamese cats.
Note: Before reading this article, I recommend that you read the first article in the series on solid cat colors, as some of the genetic explanations will be useful to understand this article.
The previous articles in the series covered:
What are point colorations?
As the name suggests, cats with point coloration patterns have their color on their "points", meaning their extremities. These cats are therefore more colored on their extremities, such as their face, their legs, and tail, with the rest of the body being clearer. Why only the extremities, you might ask? These point colorations are a form of albinism and the enzyme responsible for the color is only activated at low temperatures: the extremities, being the coldest parts of the body, result in being the only colored ones. This is also the reason why colorpoint cats are born entirely white: the temperature is uniform in the mother's womb. The kitten will then progressively get darker, and point colored cats will often get darker throughout their life. Another peculiar thing that can happen is that if a colorpoint cat is shaved, the shaved part will regrow darker, as this part will be colder!
Point coloration (especially the colorpoint pattern) is one of the rare colors which has an influence on the eye color. As you will see below, each point color pattern has an associated eye color.
There are 3 different point color patterns that correspond to different color contrasts between the extremities and the rest of the body: colorpoint, mink, and sepia.
Colorpoint
The colorpoint is the most known pattern as it’s the one associated with Siamese cats. It's the most contrasted one amongst the point color patterns, with the cat's body almost white or pale cream color. Colorpoints cats always have blue eyes and they are born all white.
Lilac tabby point, chocolate tabby point and seal tabby point from @bennyy_and_nala
Mink
The mink point pattern is often called the Tonkinese pattern, as cats of this breed typically have this pattern. It’s an intermediate pattern between the colorpoint and the sepia, and so it is less contrasted than the colorpoint. The body color is clearer than the extremities but it's never white. Mink cats have eye colors ranging from blue to green; the most common eye color for mink cats is however aquamarine eyes, a particular green-blue/turquoise color.
From left to right: blue smoke mink, lilac mink and chocolate mink from @regardfelinlaboutique
Sepia
The sepia pattern is often called the Burmese pattern, as cats of this breed typically carry this pattern. It’s the least contrasted color of the point coloration: the rest of the body is only slightly clearer than the extremities. Sepia cats have eyes going from yellow/gold to green/gold.
Chocolat sepia, lilac sepia and seal sepia from @secretlifeoftheburms
Like for the previously presented colorations, point coloration patterns can be combined with other genes: a cat can be any of the base colors, tabby or not, tortie or not, and then it can have one of the point color patterns.
Examples of possible colors are chocolate tortie sepia, blue mink, fawn tabby point…
Cinnamon mink, blue point and seal sepia from @the.tonky.trio
It can sometimes be difficult to identify the base color, but the color of the nose leather is often a good indicator of the base color. Sometimes it can also be difficult to identify between the colorpoint, sepia, and mink patterns: the contrast between the extremities and the rest of the body depends on the temperature, the cat's age, ... Looking at the eye color can often be a good indicator of the pattern type.
Blue point, lilac mink and blue mink from @tonkanees
Note that the color naming might vary depending on the region or the cat fancy. For example, there are some name variations for the point colors:
The black is often called seal: what’s a genetically black point is called seal point.
The tabby colors associated with colorpoint are often called lynx: a black tabby point is called a seal lynx (point).
In some fancies and breeds (like for the Bengal) the point color is called snow: a genetically brown tabby point is often called a seal lynx snow.
In the Burmese breed, the seal sepia is called Sable.
Finally, red point cats are often called flame point.
Cream point from @liptonthebirman
Is my cat a Siamese?
Now that we know what’s a colorpoint cat, let’s make an important clarification! Not all colorpoints cats are Siamese cats, but all Siamese cats are colorpoints. What is the difference between a Siamese cat and a colorpoint, how can we tell them apart? As we have seen, colorpoint is just a color characteristic of a cat. The term "Siamese" refers to a breed of cats that has the colorpoint pattern as one of its main characteristics. Therefore, being colorpoint doesn’t necessarily mean that your cat is a Siamese! To be a Siamese, your cat needs to have a pedigree from a recognized cat fancy association. To have a pedigree, a cat needs to be born from two Siamese cats themselves having a pedigree. Siamese cats now also have a very characteristic physique with a very thin body, angular head with a long nose, and big ears. Old-type or traditional-type Siameses are called “Thaï'' in many cat fancies and are sometimes considered a different breed.
The Siamese breed is also not the only breed of colorpoint cats: others that you may know are the Birman and the Ragdoll (I wrote an article on these two breeds!).
This might seem unimportant and just a matter of wording: however, being aware of this kind of distinctions can help you spot backyard breeding, as people may try to sell colorpoints cats of unknown origins as ethically-bred and health-tested Siamese cats.
On the left a seal tortie point and chocolate point Balinese (Siamese with long hair) from @balinese_javanese_cats and on the right a seal point and chocolate point Thai from @la_gattologa
Genetic explanation and the albino series
The C series
The different color pointed patterns are linked to the alleles of the same gene.
The C allele is the dominant one and it corresponds to cats that don’t have a color pointed pattern. So, if a cat is C/C or C/- (any other allele), it doesn’t have a color pointed pattern.
The Cs allele corresponds to the Siamese or colorpoint pattern and is recessive to the C allele: if a cat is Cs/Cs, it has a colorpoint pattern.
The Cb allele corresponds to the Burmese or sepia pattern and is recessive to the C allele: if a cat is Cb/Cb, it has a sepia pattern.
Now, you may be tempted to ask: so, if the cat is Ct/Ct, will it have a Tonkinese pattern? No: the mink pattern is really an intermediate between the colorpoint and the sepia. A Tonkinese cat is genetically Cs/Cb. In fact, Cb and Cs are codominant to each other and so they both partially express themselves.
On the left seal spotted tabby mink and on the right seal spotted tabby point from @meowlaska
This explains why in the Tonkinese breed, which is famous for its mink pattern, the colorpoint and sepia pattern are nonetheless allowed. If you breed two mink cats you can get mink, sepia, and colorpoint kittens!
Another interesting fact is that if you breed a colorpoint and a sepia cat, all their kittens will be mink!
The different alleles can be genetically tested.
At the top seal point, seal tabby point, seal tabby point and at the bottom, seal point and white and, seal point from @petsgalorestudio
Albino cats
As I said before, the different color patterns are a form of albinism. In fact, the C series is the one responsible of the albinism trait in cats. Now, the big question is: do true albino cats exist? They do, but are very rare. There are two mutations responsible for albinism:
Blue-eyed albinos: these cats are entirely white, with light blue eyes due to their albinism. It seems that their eyes are very sensitive to light. This type of albinism is caused by the allele ca which is recessive to C, Cs, and Cb. So, a cat needs to be ca/ca to be a blue-eyed albino.
These cats should not be mistaken for white cats with blue eyes which I will talk of in another article. "Classic" white cats have a dominant white gene and their eyes are not sensitive to light.
Pink-eyed albinos: these cats are entirely white, with blue eyes that have some reddish hint. This type of albinism is caused by the allele c which is recessive to C, Cs, Cb, and ca. A cat needs to be c/c to be a pink-eyed albino. It seems that this albinism allele is present in the Oriental and Siamese population, and it is very rare. This color is often called recessive white by Oriental and Siamese cat breeders.
![A pink-eyed albino cat from [1]](https://images.squarespace-cdn.com/content/v1/5e8a2944d7ce562e250eb009/1603134969045-I6POAI9Q4VTJLLSW9VDY/Albinokatze.jpg)
A pink-eyed albino cat from [1]
Here is everything you need to know about the different point colorations and their genetics. In the next article I will talk about the silver and smoke cats: stay tuned to know more about cat furs!
Sources
[1] Image Imes, D L et al. “Albinism in the domestic cat (Felis catus) is associated with a tyrosinase (TYR) mutation.” Animal genetics vol. 37,2 (2006): 175-8. doi:10.1111/j.1365-2052.2005.01409.x
Lyons, L A et al. “Tyrosinase mutations associated with Siamese and Burmese patterns in the domestic cat (Felis catus).” Animal genetics vol. 36,2 (2005): 119-26. doi:10.1111/j.1365-2052.2005.01253.x
Abitbol, Marie et al. “Allelic heterogeneity of albinism in the domestic cat.” Animal genetics vol. 48,1 (2017): 127-128. doi:10.1111/age.12503
Other article on cat coat
Solid cat colors
Torties and red cats
Tabby cats
White cats and white spotting
Silver and smoke cats