{"id":4411,"date":"2016-06-17T19:02:09","date_gmt":"2016-06-17T19:02:09","guid":{"rendered":"http:\/\/labgenvet.ca\/en\/?page_id=4411"},"modified":"2026-03-13T20:16:30","modified_gmt":"2026-03-13T20:16:30","slug":"cat-genetics-2-0-colours","status":"publish","type":"page","link":"https:\/\/labgenvet.ca\/en\/cat-genetics-2-0-colours\/","title":{"rendered":"Cat Genetics 2.0: Colours"},"content":{"rendered":"

[vc_row][vc_column][vc_column_text css_animation=”none”]<\/p>\n

Cat Genetics 2.0: Colours<\/h1>\n

\"\"<\/a>Coloration is a physical trait of cats that is visible, is not associated with disease conditions (with some exceptions), and that has been desirable since the beginning of the development of cat breeds. \u00a0The genetics of cat coloration is a good practical example of basic genetics and of heredity.\u00a0 We will see the function of single genes, the passage of genes to the next generation, and importantly, the interaction of genes with each other to give the combinations of colour traits seen between and within the cat breeds. \u00a0The good news is that the basics of colour genetics in the cat are relatively simple.\u00a0 The not so good news is that simplicity plus simplicity plus simplicity\u2026.will pretty quickly give us complexity.<\/p>\n

The Four Basic Functions of Colour Genes<\/h4>\n

There are a number of genes that contribute to the colour and the pattern of colour seen in the cat; these genes can be grouped into four levels of function:<\/p>\n

    \n
  1. Genes for basic colours<\/a>, including Colorpoint (Locus C), Agouti (Locus A), Orange (Locus O) and Locus E. These are the genes that make the pigments that give the basic colours to the cat.<\/li>\n
  2. Genes for modification of the basic colours<\/a>, including Brown (Locus B), Dilution (Locus D), and also the Dilute-Modifier Locus and the Silver (Inhibitor, I Locus). These are the genes that modify the colours defined by the basic colour genes.<\/li>\n
  3. Genes for white spotting<\/a>, including Dominant White (Locus W), and White Spots (Locus S). These genes don\u2019t make colour, rather they are responsible for the lack of colour (i.e. white).<\/li>\n
  4. Genes for colour patterns<\/a>, including Tabby, Spotted and Ticked. These genes group colour pigments within hairs and between bands of hairs to give the coat colour patterns that cats are famous for.<\/li>\n<\/ol>\n

    Keep in mind that genes come in two copies, i.e. our genetic system is in duplicate (see Cat Genetics 1.0: The Basics<\/a>).\u00a0 Also, that the effect of one copy of a gene can be dominant<\/strong> over the other copy, which is said to be recessive<\/strong>.\u00a0 For a given gene an individual cat can have two copies that are the same (either two dominant or two recessive copies), or one copy that is dominant and one copy that is recessive.\u00a0 Furthermore, the functions of one gene can mask the functions of another gene.<\/p>\n

    1. Genes for Basic Colours<\/h4>\n

    Colour is produced by special pigment chemicals called melanins.\u00a0 Pigment is produced in special cells called melanocytes, which are found within the hair, in the skin and in the eyes.\u00a0 For the cat, the colour and pattern of the pigment within the hair is the most important.<\/p>\n

    The two basic pigments that contribute to coloration are black (eumelanin) and yellow (pheomelanin) pigments.\u00a0 It is the interplay between the expression of genes for these two basic pigments that give the cat its basic coloration. \u00a0It is important to realize that a single hair can be all black, all yellow, or have bands of black and yellow pigment.<\/p>\n

    Colorpoint and Locus C<\/strong><\/p>\n

    The C Locus involves a master gene for pigment formation.\u00a0 When the gene is active, both black and yellow pigments can be formed.\u00a0 When the gene is mutated and not active, no pigment is formed.\u00a0 A recessive mutation at the C Locus will give a white (albino) cat, but this is not something that is desirable for cat breeders.\u00a0 However, cats have a very interesting series of additional mutations at the C Locus that give the Colorpoint traits. Colorpoint refers to the fact that ears, paws and tails of the cat are more darkly pigmented compared to the body.\u00a0 This is the key component of coloration in several breeds including Siamese and Burmese, and can give colorpoint variations such as Tonkinese.\u00a0 Recently a new variation of Colorpoint was identified in the Burmese breed, termed Mocha or Bangkok.\u00a0 There is an order of dominance of these variations (mutations) as follows:<\/p>\n

    \"\"<\/a>Other animals such as rabbits also have colorpoint mutations in their Locus C genes.\u00a0 Dogs do not.<\/p>\n

    Agouti (Locus A) <\/strong><\/p>\n

    The Agouti gene, found at Locus A is the master gene for yellow pigment production.\u00a0 In the cat, the Agouti gene is either active, allowing yellow pigment to be formed, or not active, which eliminates yellow pigment formation but still allows black pigment to be produced. \u00a0A normal (dominant) Agouti gene allows cat hairs to be banded yellow and black, and thus allows Tabby genes to be expressed (lots of fun, see below).\u00a0 A recessive mutation at Locus A (a\/a) is responsible for solid coloured (“self”) cats.\u00a0 This mutation gives the recessive black cat coloration, called “seal” is some breeds such as the Siamese.\u00a0 The (a\/a) mutation nullifies the effects of the Tabby genes- without yellow pigment, black bands are now on a black background to give a black cat.\u00a0 In dogs Locus A has more variations than seen in cats and is responsible for Dominant Yellow, Black and Tan colorations as well as recessive black (see Dog Genetics 2.0: Colours<\/a>).\u00a0 Although we have the Agouti gene within our genome, it is not involved in the colour traits of hair in people.\u00a0 Pity.<\/p>\n

    \"\"<\/a>Orange (Locus O)<\/strong><\/p>\n

    The Orange gene (Locus O) gives the Red\/Orange coloration of cats and is interesting for two reasons.\u00a0 First of all, it is unique to cats. Secondly, it is found on the X chromosome, making the Orange coloration sex linked.\u00a0 There are two versions of the gene, the dominant Orange (O) allele and the recessive, wild-type non-orange (o) allele.\u00a0 Orange (O) blocks black pigment (eumelanin) formation and forces only yellow pigment (pheomelanin) to be formed.\u00a0 Non-orange (o) allows both yellow and black pigment to be formed.\u00a0 Female cats, possessing two X chromosomes, can have orange coloration (O\/O), orange and black coloration (o\/o), or a mottled mix of orange and black coloration called Tortoiseshell (O\/o).\u00a0 This is due to a process called “random X-chromosome inactivation” that occurs in mammalian females during embryonic development, whereby only one X chromosome is functionally active while the other is condensed and inactive.\u00a0 Male cats, with only one X chromosome cannot normally be tortoiseshell; the rare males that are usually have an extra X chromosome (XXY).\u00a0 The dominant O allele of Orange will block the effects of the A allele of Locus A (Agouti) and will thus block the Tabby patterns.\u00a0 This blocking of Tabby is not absolute- it is more pronounced for the body of the animal while Tabby stripes are still evident on the legs, tail and face of the orange cat.\u00a0 Unfortunately, the Orange gene has not as yet been characterized.\u00a0 Functionally Orange acts a bit like the Agouti Dominant Yellow that is seen in dogs (see Dog Genetics 2.0: Colours<\/a>).\u00a0 Dogs do not have sex-linked colour patterns.\u00a0 Pity.<\/p>\n

    \"\"<\/a>Locus E<\/strong><\/p>\n

    Locus E, also known as Extension, is an important gene for allowing black pigment (eumelanin) production. \u00a0Having said this, Locus E is not very important for most cat breeds although it is responsible for the Amber colour (e\/e) that can be seen in Norwegian Forest cats and the Russet coloration (er\/er) seen in Burmese cats.\u00a0 Locus E is much more important in the dog and the horse where (e\/e) is responsible for the beautiful golden coloration of the Golden Retriever, the rich red coloration of the Irish Setter dog and the noble Sorel\/Chestnut coloration seen in the horse (see Dog Genetics 2.0: Colours<\/a>; Horse Genetics 2.0: Colours<\/a>).<\/p>\n

    2. Genes for Modification of the Basic Colours<\/h4>\n

    The colour modifying genes do not make the colour pigments, but they do influence the shade of the colour, usually by reducing its intensity i.e. washing it out.\u00a0 Modifying genes include Brown (Locus B), Dilution (Locus D), and also Dilute-Modifier (Locus D-M) and Silver (Locus I, Inhibitor).<\/p>\n

    Brown (Locus B)<\/strong><\/p>\n

    The Brown gene (Locus B) in the cat affects the intensity of black pigment. \u00a0Brown is a recessive trait that will modify the normal black pigment (B) to a brown colour (b\/b) or to a cinnamon colour (b\u2019\/b\u2019).\u00a0 Normal coloration is dominant over brown, which in turn is dominant over cinnamon.<\/p>\n

    \"\"<\/a>Dilution (Locus D)<\/strong><\/p>\n

    Dilution is another gene that modifies the normal colours and will wash out or dilute both black pigment and yellow pigment.\u00a0 Dilution is a recessive trait that will modify normal black pigmentation to give a grey colour (d\/d) often called Blue.\u00a0 Dilution can combine with B locus Brown (b\/b) to give Lilac (Lavender) coat colour and with B locus Cinnamon (b’b’) to give Sable (Fawn) coat colour.<\/p>\n

    \"\"<\/a>The Dilution gene can also influence Orange pigmentation (Locus O), which it washes out to give a Cream coloration.<\/p>\n

    \"\"<\/a>Dilute-Modifier Gene<\/strong><\/p>\n

    There is a gene called Dilute-Modifier in the cat that in its dominant form (Dm) can modify diluted (d\/d) coat colours.\u00a0 Blue (d\/d) coloured cats are modified to Blue-Caramel coloration.\u00a0 Lilac coloured cats (b\/b, d\/d) are modified to give Caramel on Lilac coloration, while Cinnamon coloured cats (b’\/b’, d\/d) are modified to give Caramel on Sable coloration.\u00a0 Cream coloured cats (orange coloured cats from Locus O, d\/d) are modified to give Apricot coloration.\u00a0 The Dilute-Modifier gene has not as yet been cloned nor fully characterized.<\/p>\n

    the presence of d\/d will cause a further washing out of pigment colours.\u00a0 Locus B (Brown) now gives \u2018Carmel\u2019 shades of colours while Locus O (Orange) gives Apricot.\u00a0 The Dilute-Modifier gene is not as yet cloned or characterized.<\/p>\n

    Silver (Inhibitor, Locus I)<\/strong><\/p>\n

    Silver is a gene that suppresses melanin production somewhat with yellow pigment (pheomelanin) production being more suppressed than black pigment (eumelanin) production.\u00a0 For tabby cats, the background coloration becomes “silver”, giving a Silver Tabby.\u00a0 For solid cats, the base of the hair becomes pale, giving a Silver Smoke coloration.\u00a0 Unfortunately, the Silver gene is not as yet cloned.<\/p>\n

    3. Genes for White Spotting<\/h4>\n

    White markings are a prominent feature of cat colour genetics.\u00a0 Interestingly, white is not a colour per se, but is rather a lack of colour.\u00a0 In fact, white results from a developmental lack of cells (called melanocytes) that produce pigmentation.<\/p>\n

    Dominant White (Locus W)<\/strong><\/p>\n

    Dominant White, from Locus W, can give an all-white cat. \u00a0Dominant White as it\u2019s name indicates is dominant in that only one copy of the mutated gene (W) is needed to give the trait. \u00a0The recessive and normal version of the gene is called w. \u00a0Dominant White will mask the effects of the Colorpoints (Locus C), Agouti (Locus A), and Brown and Cinnamon (Locus B).\u00a0 \u00a0Dominant white can be confused with recessive white (albino, c\/c, coming from the C locus).\u00a0 Unfortunately, Dominant white can be associated with deafness, particularly when it is present in two copies (W\/W).<\/p>\n

    White Spots (Locus S)<\/strong><\/p>\n

    Cats can have a full range of white markings, from none, to moderate, to predominant.\u00a0 The Locus S is involved in producing white markings, but the gene has not been cloned and it is not known if Locus S represents one gene or several genes. \u00a0While a comprehensive understanding of the genetics of white spots in cats remains for the future, some breed specific advances have been made. \u00a0The White Gloving pattern seen in the Birman breed is caused by a mutation in the Kit gene, and displays recessive genetics.<\/p>\n

    \"\"<\/a><\/p>\n

    4. Genes for colour patterns<\/h4>\n

    Cats are known for their striking colour patterns, including stripes, spots and swirls of colour.\u00a0 When it comes to colour patterns, dogs are poor cousins to cats. \u00a0Colour pattern effects are produced by different levels of expression of the basic pigments, black and yellow, both between groups of hairs and also within the hair shaft itself.\u00a0 Collectively, colour patterns are called Tabbies but this oversimplifies the genetics as there are several genes involved in giving patterned effects.\u00a0 Tabbies require a normal functioning Agouti locus (A\/-), and they will be masked in a black cat (a\/a).\u00a0 Tabby patterns can overlay the basic colour genes as well as the modifying colour genes.\u00a0 Three genes associated with colour patterns are mentioned, including Mackerel and Classic Tabby, Ticked Tabby and Spotted Tabby.<\/p>\n

    Mackerel and Classic Tabby <\/strong><\/p>\n

    Mackerel Tabby and Classic Tabby are caused by the same gene (Ta), with Mackerel being dominant over Classic Tabby.\u00a0 In Classic (or Blotched) Tabby, swirls and blotches of black and yellow pigment occur.\u00a0 Mackerel Tabby gives the familiar alternating stripes of black and yellow pigment seen in cats.\u00a0 Think little tigers.\u00a0 In the case of the classic tabby, there are swirls and black and yellow pigmentation spots.<\/span><\/span><\/p>\n

    Ticked Tabby<\/strong><\/p>\n

    In the Ticked Tabby pattern, an alternation of yellow and black pigment occurs within the hair shaft itself giving the cat a stylish \u2018salt and pepper\u2019 sheen to its coat as seen in Abyssinian cats.\u00a0 Ticked (Ta) is dominant over non-ticked (ta).\u00a0 The Ticked Tabby locus will mask the stripes and swirls seen with Mackerel and Classic tabby patterns.<\/p>\n

    \u00a0<\/strong>Spotted Tabby<\/strong><\/p>\n

    The Spotted Tabby locus is responsible for spots of black pigment on a yellow pigment background.\u00a0 Think of little leopards.\u00a0 Spots are seen in traditional cat breeds such as the Ocicat and in hybrid breeds such as the Bengal.\u00a0 The genetics of the Spotted Tabby are not well understood and it is probably polygenic.<\/p>\n

    Other Traits to Mention<\/h4>\n

    Short\/Long Hair<\/strong><\/p>\n

    The genetics of short hair and long hair is relatively straight forward.\u00a0 Short hair is the dominant copy (L) while long hair is the recessive copy (l\/l) of the responsible gene.<\/p>\n

    Curly Hair Coat<\/strong><\/p>\n

    Curly Coat is an interesting trait coded for by the K gene.\u00a0 Dominant mutations (Ks<\/sup>) give the hair coat of the Selkirk Rex, while recessive mutations (kre<\/sup>, khr<\/sup>) give the hair coat of the Devon Rex and the Sphinx, respectively.<\/p>\n

    Cat Colours and Heredity<\/h4>\n

    We have just talked about the genetics of cat colours. We should also mention the heredity of cat colours, that is to say, the passage of the genes for coat colours from one generation to the next.\u00a0 To help the discussion, think of the cat genome as a deck of playing cards (see Cat Genetics 1.0: The Basics<\/a>) where each gene (or card) is represented twice.\u00a0 From this deck of cards, with its own particular combination of cards is constructed a house of cards, or in this instance, a cat.\u00a0 Between generations, the house of cards is collapsed and the deck of cards gets shuffled and then cut in two.\u00a0 A new house (cat) is built from a new combination of cards, half coming from mom and the other half from dad.\u00a0 When you think of all the known genes with all their variations that are involved in establishing the colour of a cat, then add in the genes not as yet characterized, this can give a whole lot of new possible combinations between generations.\u00a0 That\u2019s genetics.\u00a0 And the challenge of breeding.<\/p>\n

    Colour Chart for Cat Colour Genetics (Simplified)<\/h4>\n

    For a visual representation of colour genetics covered in this article, see the colour chart\u00a0Cat Genetics 2.1: Colours Chart<\/a>.
    \n[\/vc_column_text][\/vc_column][\/vc_row][vc_row el_class=”bloc_info”][vc_column][vc_column_text]<\/p>\n

    Resources:<\/strong> This review of the genetics of cat colours is not meant to be exhaustive.\u00a0 It is the beginning of the story rather than the end of one.\u00a0 Further information and details can be found on these websites:<\/p>\n

    https:\/\/en.wikipedia.org\/wiki\/Genetics<\/a><\/p>\n

    https:\/\/en.wikipedia.org\/wiki\/Cat_coat_genetics<\/a><\/p>\n

    http:\/\/sparrows-garden.com\/genetics.html<\/a><\/p>\n

    http:\/\/messybeast.com\/colour-charts.htm<\/a>
    \n[\/vc_column_text][\/vc_column][\/vc_row]\u00a9 2022 Dr. David W. Silversides<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

    [vc_row][vc_column][vc_column_text css_animation=”none”] Cat Genetics 2.0: Colours Coloration is a physical trait of cats that is visible, is not associated with disease conditions (with some exceptions), and that has been desirable since the beginning of the development of cat breeds. \u00a0The genetics of cat coloration is a good practical example of basic genetics and of heredity.\u00a0…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-4411","page","type-page","status-publish","hentry","description-off"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/4411","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/comments?post=4411"}],"version-history":[{"count":30,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/4411\/revisions"}],"predecessor-version":[{"id":24512,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/4411\/revisions\/24512"}],"wp:attachment":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/media?parent=4411"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}