College of Cat Genetics: Part XV
by Patricia Turner
Study Unit 15
Excluding considerations of type, the Colourpoint (Himalayan) combines genes for Siamese previously found only in the Siamese breed with those for longhair. The late Mr. Stirling-Webb can be regarded as the Colourpoint (Himalayan) "designer" in England and described his breeding techniques in somde detail in Pedigree Cats by P.M. Soderburg. Although previous experiments had been made in the USA by C.E. Keeler and Virginia Cobb, these had not taken 'type' into consideration and it was not until a visitor to the Siamese Cat Club Show, 1947, described a longhair Siamese patterned cat with Persian type which he subsequently acquired that he set about drawing up breeding programmes in earnest. The breed was recognized for Championship status in England in 1955.
Brown cats, too, were not unknown before the advent of the first solid Chocolate brown breed known in the USA as the Havana Brown and in Great Britain at first as the Chestnut Brown Foreign.
The first recorded brown cats (not the brown of Brown Tabby or Burmese dilution) were reported in 1894, whilst other Brown cats with the definite Siamese type were reported in the 20s. The breeder who can be credited as 'designer' of the Chestnut Brown was the late Miss von Ullman who commenced work in 1951. Records show her programme to have been as follows (although some matings to Russian Blues were made, thus accounting for the later incidence of Brown dilutes). Her colleagues were the late Mrs. Hargreaves, Mrs, Monro-Smith and Mrs. Fisher. Another early breeder was Mrs. D.M. Clark.
Mating Black Shorthair to Chocolate Point Siamese.
Mating the black F1 like to like to produce Black Shorthair; Seal Point Siamese; Brown Shorthair; Chocolate Point Siamese (expected ratio--9 Black Shorthairs: 3 Seal Point Siamese: 3 Brown Shorthairs: 1 Chocolate Point Siamese).
Brown Shorthair -crossed to Chocolate Point Siamese to produce Brown Shorthair and Chocolate Point Siamese (expected ratio--all Brown Shorthairs from the homozygotes and 1 Brown Shorthair and 1 Chocolate Point Siamese from the heterozygotes).
Brown Shorthair to Brown Shorthair.
It will be appreciated that the Brown Shorthairs produced at Stage Four need not necessarily have been homozygous for full colour and that some carried Siamese. Since the breed was recognized for Championship status, its English breeders have concentrated on selection for Siamese type by backcrosses to Siamese rather than on the production of the full colour homozygote.
Another who can be described as a "cat designer" is Dr. Rachel Salisbury who detailed her work on the addition of sex linked color and pattern to the Chinchilla, Shadeds and Smoke breeds in the "ACFA Bulletin" in 1963. There are now a number of breeders throughout the world working on what are popularly known as Cameo programmes. The varieties produced are as follows: Red Smoke, Cream Smoke, Shaded Red, Shaded Cream, Red Chinchilla, Cream Chinchilla, Smoke Tortoiseshell, Smoke Blue Cream, Shaded Tortoiseshell, Shaded Blue Cream, Tortoiseshell Chinchilla, Blue Cream Chinchilla. (Note, these are technical descriptions and not suggestions for breed names.)
It is interesting to note that no browns have been reported in Smoke of Chinchilla breeding to date. This may be due to the fact that brown is not commonly present in the long hair breeds although there is one theory for the inheritance of smoke that would make its appearance genetically impossible. The inheritance of smoke in any colour remains a subject for speculation and indeed the author would be interested to hear from any Smoke breeder willing to provide breeding records so that the matter can be clarified. If the Chocolate Brown Smoke is a viable possibility then no doubt future generations of cat fanciers will be breeding Lilac Smokes, Shaded Lilacs and Lilac Chinchillas.
These examples show how genes already present in cat populations may be reshuffled by planned programmes of matings. The same techniques apply whether attempting a new variety or improvement within those already established.