Previous    Back to Tonkinese FAQs    Next

 

The Three Tonkinese Coat-Patterns

© Linda Vousden

 

The Tonkinese coat-pattern is probably the most discussed, and written about, aspect of the breed

because the genetic behaviour of the Tonkinese coat-pattern is unique among cat breeds.

Why is it unique? Because there isn't actually a gene that produces the subtle intermediate/mink Tonkinese coat-pattern. It is caused by a quirk of nature, and can only be seen if the cat inherits a combination of two different versions of the albinism gene from its parents - the version that produces the pointed coat-pattern in the Siamese plus the version that produces the relatively solid coat-pattern in the Burmese. You can read more about the genetics of the Tonkinese coat-pattern in the book Tonkinese Cats

Normally, one version of a gene is dominant to another (for example in the gene for hair length, short-hair is dominant to long-hair); but the Tonkinese mink coat-pattern comes about because the version inherited from the Burmese parent (cb) is co-dominant with the version inherited from the Siamese  parent (cs) - ie  one will never dominate the other. So they combine as cbcs to produce both of their individual effects in one coat-pattern. This means that we get an relatively solid coat combined with darker points

              

 self (cbcb)    x     pointed (cscs)

 

inherited cb + inherited cs   = cbcs (Tonkinese)

The next step is even more interesting. When you mate two Tonkinese with the intermediate/mink coat-pattern (cbcs) each parent is carrying both the 'solid' (cb) and the pointed (cs) versions of the coat pattern gene - as the kitten will inherit only one version from each parent there are three possible coat-pattern combinations in the kittens  :-

                                                                                                    

Tonkinese (cbcs)   x    Tonkinese (cbcs)

 

                                           

cb - inherited from parent 1          cb  - inherited from parent 1             cs - inherited from parent 1

cb - inherited from parent 2          cs - inherited from parent 2             cs - inherited from parent 2

 cbcb = Tonkinese                   cbcs = Tonkinese                       cscs = Tonkinese

with the self coat-pattern         with the Tonkinese coat-pattern     with the pointed coat-pattern

and yellow/green eye colour           and aqua eye-colour                     and clear blue eye-colour

 

 

 

Five irrational misconceptions that we still hear -

  1. We still read that when Tonkinese are mated together they produce Tonkinese, Burmese and Siamese - this is wrong! Tonkinese mated together can only produce Tonkinese.

  2. Some people use the expressions Burmese-variants or Siamese-variants - this is wrong! They are solid and pointed Tonkinese.

  3. Some people continue to say that the Tonkinese do not 'breed true'  - this is wrong! It has come about because these people cannot (or will not) understand the meaning of the word unique - they try to fix the Tonkinese into the breeding patterns of other breeds, and so demonstrate their limited understanding of feline genetics. There is much more to a cat than just its coat-pattern. The Tonkinese breeds as consistently for type (head and body conformation), eye-colour, coat-type and character as any other breed & more so than some - it also breeds consistently for  the three coat-patterns.

  4. The Tonkinese are just a hybrid of Burmese and Siamese.  If the accepted use of the word hybrid, in the Cat Fancy, is a cross of two cat breeds then the Tonkinese are hybrids,  but no more so than the - Angora, Asian, Bengal, Balinese, Bombay, Burmilla, Colour-Point BSH, Exotic, Javanese, LaPerm, Norwegian Forest, Occicat, Oriental SH, Ragdoll, Seychelloise, Snowshoe, Somali, Tibetane, Tiffanie and so on .....  ..... and the cats breeds that are not derived from a cross of two pedigree breeds were derived, at some point, from unknown non-pedigree crosses!

  5. The further down the generations you breed the less solid and pointed coat-patterns you breed - this is impossible! As has been explained above the genes for the solid and pointed coat-patterns are perpetually heterozygous, they will always produced all three coat-patterns. You may have one or two litters that have less solid or pointed coat-patterns than mink coat-patterns - but over a number of litters the average ratio of coat-patterns must fall true to the genetics i.e 25% solid, 50% mink, 25% pointed. So if you are experiencing a lack solid and/or pointed coat-patterns then somewhere in your pedigrees there are cats with incorrectly registered coat-patterns.

COPYRIGHT NOTICE - You may print-off any page for your own information but, unless indicated otherwise, I retain copyright of

photographs, illustrations & articles used on the Mymystic/TBC web site. You may  not use them without my express permission.    - Linda Vousden.

 

MYMYSTIC TONKINESE HOME  ||  MYMYSTIC TONKINESE DIRECTORY  ||  TONKINESE BREED CLUB HOME