From the Autumn 1978 Newsletter of The Havana Cat Club
Pure Breeding of the Havana & Foreign Lilac
Two Further Recessives
(Note: this article was written before Caramel was widely known)
John S Harrison
When I wrote the article entitled "Pure Breeding of the Havana & Foreign Lilac" in1977 I dealt only with two recessive alles, namely 'siamese' and 'blue'. At that time I was tempted to include two other recessives, 'light brown' and 'recessive white'; but at that time seemed ill advised. The situation has now changed and the existance of the two alleles has become not only a matter of general knbowledge, but also of genuine concern to those who wish to establish 'pure breeding lines' of the Havana or Foreign Lilac.
'LIGHT BROWN' DILUTION (also referred to as 'Pavane' and 'Cinnamon')
Many breeders will have seen examples of the so called "Cinnamon" or 'Light Brown' Shorthair on exhibition at various shows. For those who have not seen an example of the colour it may best be described as being a rich sandy-buff, which is dissimilar to the brown of the Havana, and is considered to be an attractive coat colour.
The 'light brown' gene is recessive to that which is responsible for the production of the brown colouring seen in the Havana and Chocolate Point Siamese, and can accordingly be carried by cats of the normal brown colour (and therefore by cats of the normal Lilac colouring).
The 'light brown' gene is responsible for the colour of the Red Abyssinian [subsequently renamed Sorrel Abyssinian], and it is from crosses to this breed that the colour was introduced into the Havana - indeed the cat referred to as the 'Cinnamon' can be regarded as a non-agouti version of the Red Abyssinian, but of Siamese body type.
One cannot detect visually which Havanas may carry the recessive 'light brown' allele; but two such Havanas mated together will produce both the normal brown cat, and the 'light brown' cat. In the self form the differences will be readily apparent, but in combination with siamese markings the differences might be less obvious and novices may well experience considerable difficulty differentiating between a pointed kitten of good chocolate and a 'light brown' point.
When combined with the blue allele, the 'light brown' cat is transformed into a dilute version of the Foreign Lilac, and these will appear as a lighter, more fawn colour than the conventional Lilac. Again novices may experience difficulty seperating 'light lilac' and normal lilac colouring in the self, but especially so when combined in the Siamese Pointed kitten.
The 'light brown' colouring is traceable back through one breeding line. If you are intent on producing a pure breeding line of Havana/Foreign Lilac it may be advised to research your pedigrees, and those of studs you intend to use on your queens.
To eliminate the allele is difficult, and one cannot be certain of freedom from the allele, if pedigrees contain known or potential carriers of the allele, without test mating to either a 'light brown' or known carrier. Recessives can be carried for an indeterminate and indefinite number of generations and other than test mate there is no way of revealing their presence. Ideally a test mating to a 'light brown' should be carried out, but remember ALL the resultant kittens will carry 'light brown'. If 10 kittens are produced from such a test mating, and all are 'normal brown' then it is safe to assume the cat does not carry the recessive. If a light brown kitten is produced from two Havanas then BOTH parents must carry the allele.
RECESSIVE WHITE
There are essentially two types of White cat, one caused by a dominant gene for white 'colouration' which masks an otherwise coloured cat. In other words the cat is genetically a coloured cat with the addition of one (or two) gene for dominant White. Simply a coloured cat in a white coat! This form of white is well known in the Cat Fancy and is responsible for the Long Haired White, the British White and the Foreign White.
The second for of white cat is the recessive white, otherwise knoiwn as an albino, and it is this form of white which is the cause of concern and topic of discussion in the Fancy at the present time. Let me stress that in no way is any recognised breed of white cat involved in the matter of 'Recessive Whites'.
The 'recessive white' is infact an incomplete albino, for it has some degree of pigmentation, as indicated by its milky blue eye colouring - the complete albino has an apparently pink eye. The albino series of alleles has an order of dominance:
from Full Coat Colour
to Burmese colouring
to Siamese colouring
to incomplete albino
to complete albino.
In each case there is reduced pigmentation. Because the albino is low in the series it can be carried by cats of a phenotype higher up the series - thus a Havana, Chocolate Burmese, and Chocolate Point Siamese can all carry an allele for 'recessive white'. If two such animals are mated together 'recessive white' or albino kittens will result. Because albino is recessive two albino cats mated together cannot produce coloured kittens.
In the late 1960's an 'Albino Siamese' was introduced into the United Kingdom from the United States of America. This cat was an incomplete albino, and is the ancestor of cats today which are known as 'Recessive Whites', and cats carryingthe albino allele.
Whether or not one has ethical or moral objections to the recessive white is a personal matter, and is of no importance in this article. It must be remembered however that the Albino animal may suffer as a consequence of the lack of pigment. Should there be any question that a cat is a carrier of 'recessive white' the owner has two alternatives, assuming that he or she wishes to breed for purity.
The first alternative is to test mate the cat(s) in question either by mating to a Recessive White or a known carrier. However in so doing you will be producing even more carriers.
The second alternative if you suspect your line has the recessive will by judicious mating to Siamese to remove the allele from successive generations. Because a cat may only have two alleles for any character, and a pure bred Siamese has two for Siamese markings, a mating between a Siamese and a Havana/Foreign Lilac which is a 'recessive white' carrier, or potential carrier, will result in full colour kittens and Siamese marked kittens. Only two genes can be possessed for a character and so the coloured kittens will have taken a gene for full colour from the Havana/Lilac parent, and the other from the Siamese parent -- accordingly these coloured kittens cannot possibly carry the recessive white allele - though of course the Siamese kittens may well, and these should be neutered and go as pets.
The coloured parents can be neutered and their coloured offspring kept to carry on the line. It is therefore simple to eliminate the recessive white allele, without the need for test mating. The next step to purity then is to breed out the Siamese gene.
© John S Harrison, Autumn 1978
(Note: this article was written before Caramel was widely known)