SUNSHINE COLOUR IN SIBERIAN CATS

Transcription

1 SUNSHINE COLOUR IN SIBERIAN CATS I propose for recognize a new colour, named sunshine, in Siberian Cats. A brief history When I started to manage the Book of Origin of my club, AFeF, I noticed genetic inconsistencies in the transcriptions of the pedigrees of Siberian Cats. I became suspicious and I started to explore the issue. Starting, mainly from Onix Gloria lines, you can find the golden tabby ones, but it is immediately evident that golden cats are born out two parents which are not golden. The golden colour is a colour which, traditionally, has been selected mainly in Persian cats and it's given by the gene Wb (wide banding) that acts as dominant and "widens" the base of the hair of an agouti cat leaving colour "golden-brown" and pushing the hair colour towards the ends of each hair (black / blue or red / cream). In Persian cats, however the selection was essentially in the chinchilla and silver shaded cats which are cats with the Inhibitor gene (I) and Wb, I.e. cats having white hairs except at the tip. As in all cats with the inhibitor gene the pawpads colour match with the hair on the gene B, O or D, may be with white (S), so.. e.g., A Black Silver Shell will have also black fingertips/pawpads. So, on balance, in Persians, the golden cat is a chinchilla cat without the inhibitor gene... (A- B- Wb- ii) But if you look at the pedigree of a Siberian golden, you immediately notice that golden cats are also born out two non-golden cats and that the presumed gene Sunshine behaves apparently as a recessive gene. Some people believe this colour is the same than in the Persian and think that: some breeders may have declared as brown tabby, cats being in fact golden ones, but honestly they are a bit too many to be merely the product of a mistake! Even admitting that the warm colour of golden Siberian could be "revived" by the polygenes that act on other colours, the base must be a new recessive colour. This point of view is supported by the fact that I've seen several pictures of Siberian golden litter out non golden parents and I ve seen ONLY kittens golden out two golden parents. This topic passed over the silence for various reasons until recently, when someone introduced the silver gene (I)... Then cats having both colours, silver and the sunshine, appeared.. Assuming that it is the same golden colour of the Persians, it would have been IMPOSSIBLE! Some peoples keep saying that these cats show rufism, but I think that the rufism has a different look and it don't appear neither in this colour or with this distribution. Breeding Abyssinian and Somalis cats, which have the most developed rufus polygenes, I am accustomed to meet silver Abyssinian and Somalis cats with rufism, even strong and widespread, but this distribution is by no means like what we find in these bimetal called cats; i.e. cats with the inhibitor gene (I-), the agouti gene (A-) and the colour sunshine. At present there are no reported Siberian cats sunshine non-agouti (aa), but Siberian cats are mostly agouti (A-) In some cases some people indicates the bimetal girls as females tortie (black and red, blue and cream), but the colour in my opinion is different and these cats have NEVER pawpads with red/cream and in my experience, even a cat with a little amount of red shows some pink in the pawpeds and the pedigrees without genetic red inside can confirm that. To summarize: 1

2 A = agouti - existing genetic tests B / b / bl = black-chocolate-cinnamon - existing test O = red - test does not exist D = dilution gene when mutated (d) - existing test C / cb / cs = gene of the albino series - existing test I = inhibitor gene (silver / smoke) - Test does not exist T / Tb - Ta - Sp genes in various capacities related to the type of tabby - tests do not exist Wb = Wide Banding (involved in the Golden Classic) - test does not exist Sunshine, assumed recessive mutation, may be another allele in locus E? We waiting for a research to find this new gene and consequently a new test. We have a pending research with Leslie Lyons, BS, MS, PhD, now at University of Missouri, before at UC Davis California My personal opinion, based on what I've just mentioned here, is that in Siberian cats this colour may be a mutation, which I called sunshine, which is transmitted as recessive, influenced by polygenes as for the intensity of colour and its distribution. I have seen a very similar colour in Kurilian Bobtail cats, also coming from ex-urss countries, as well as in short-haired street cats in Ukraine. May be a similar colour is present in some thai and british cats, but not exactly the same (may be another allele too) The breeders who have selected this "reddish" colour, have used a very strong inbreeding to fix the character, confirming that the gene is probably recessive. The first bimetal cats probably were hidden, as often happens, to prevent breeding problems, and several people still call them silver cats with very high rufism, without understanding that it is something quite different from that and keeps them away from reproduction. We have some cats with a strange reddish patches, only in silver cats carrying sunshine. Our opinion is that, in some way, this gene sunshine, in eterozygosis can show up some golden patches in combination with the gene I. ALL silver cats carrying sunshine which I seen have this patch! The first cat I seen with that is Yankee Silviassib*PL now in Veselka Cattery in Italy The only way to make things clearer would be able to find the mutated gene sunshine and consequently the corresponding test; this would lead to easier recognition of the new colour in the various feline federations. Pictures and related pedigrees are available for further investigations. I started to collect sample of sunshine with and without silver in I controlled all cats in live or by pictures to be sure of this colour. I sent the samples of 42 cats to UC Davis, but the project can t start at this moment because a problem of money. For that I propose to recognize this colour even we don t have the test for. I propose that only for siberian cats because I can speak only about this breed. That it s very important because we can put a correct colour on the pedigrees otherwise those cats are registered as black/blue/tortie silver or Brown/black/blue/tortie tabby and it s very hard to know the true colour in the pedigrees. Keep in mind that, for example, in TICA the golden siberians too are all registered as brown tabby! Those colours are very liked by people but the silver ones can t be showed now. Similarities with Amber mutation at locus E. 2

3 The sunshine coloration looks dark at birth getting clearer afterwards, somewhat similar to the amber (ee) in the Norwegian Forest cats. Like in the adult amber cats the pawpads of these cats are blacks / blue tortie or tortie females (in non-white cats of course) depending on base colour but, differently than in the amber, the kittens don t have the rose paw pads at birth. Like the amber cats the nose in agouti cats is ROSE, without the line on the nose leather as usually you can see in the agouti cats. I put here some consideration of Dr.Vet. Mark Peterschmitt in his research about Amber Norwegian Forest. Three different pigments are described in cats : 1) The black pigment, also called eumelanin (e.g. black cats) 2) The yellow/tawny pigment, also called phaeomelanin (e.g. golden tabby cats). Caused in the polygenetic mechanism of the rufism, phaeomelanin also can vary from yellowish to reddish. 3) The red pigment, also called trichochrom or orange (e.g. red cats); it is bounded to the female allosome (x-chromosome); further is red/orange epistatic to amber. Today it is known that trichochrom is NOT eumelanin, but an independent pigment. The Extension gene action is well known in other animal species, it contributes to the MC1-R synthesis, a protein which is also called Melanocortin 1 Receptor. This receptor is necessary and essential to produce the black pigment (eumelanin) after the alpha-msh hormone binding into this MC1-R receptor and a following chemical chain reaction. The MC1R gene enables the black pigment extension in hair, that s why it s also called <<Extension gene>>. On the contrary the yellow pigment (phaeomelanin) will be synthesized, as soon as the eumelanin synthesis is impossible, for example when the MC1-R receptor is mutated and therefore ineffective for the eumelanogenesis. There is also a second opportunity for the phaeomelanin synthesis with a perfectly functional MC1R receptor. The A+ allele (in agouti cats) enables the agouti protein synthesis and has strong and complex interactions with the MC1-R receptor: the agouti protein can actually bind in the MC1-R, it prevents therefore the alpha-msh hormone binding and acts as an antagonist for the MC1-R receptor. Consequently the phaeomelanin synthesis is promoted, whereas the eumelanin synthesis remains marginal. These A+- cats are agouti (=tabby) and have a more yellow colour as the non-agouti aa cats (solid or self). The agouti protein in non-agouti cats is actually mutated and consequently does not prevent the alpha-msh hormone binding into the MC1-R receptor. Therefore non-agouti cats can always produce eumelanin pigment and look black. This MC1-R characteristic explains also the strange interactions between amber and agouti. It was always supposed in the past that there were only amber agouti cats (tabby), because all amber cats showed a tabby pattern. Nevertheless the amber non-agouti colour (solid) is currently well-known and existed since many years with a misleading ghost tabby pattern that caused confusion with the amber agouti cats. (omissis) A mutation in the Extension gene is able to cause a mutated and ineffective MC1-R receptor. The 3

4 cat cannot consequently produce any eumelanin and will only synthesize phaeomelanin. This mutation is symbolized <e>. There are particular interactions between the Agouti and Extension genes, because both genes act in the same pigmentation stage. Numerous animal species are currently known to have such <e> mutation(s) in their genetic population pool. But we didn t know any <e> mutation in the cat family until now. Moreover none of these <e> mutations have all amber characteristics from the Norwegian Forest Cat. For example: <e> mutations from the other species show only an epistatic effect to the agouti- alleles and this epistasy is not observed completely at the amber cats. So may be that new colour Sunshine is another allele in locus E. For sure the mechanism of action is very similar even if we don t know at present any sunshine non agouti, but we program one mating for. Presentation of sunshine colour. This mutation concerns only the hair colour not the skin. The cats are genetically black: their coat is yellowish-apricot and their skin black, what can be seen at dark paw pads and dark eyes rims Because out non-sunshine cats we can have sunshine kittens and sunshine matings only give sunshine kittens and there is no correlation between sunshine inheritance and the sex, I suppose this colour is an autosomal recessive trait We testing many cats for different genes and they showed that they are genetically black (B/B), which excluded the chocolate (b) and cinnamon (bl) alleles and also excluded the Amber gene (e) and the burmese (cb), and albinos (c) alleles. Age dependent colour maturation is clearly surprising; all kittens are initially mostly brown tabby or blue tabby for the dilute coat and then their original colour brightens and adults show a warm apricot -like colour for the black based colour or pinkish beige like colour, for the blue based colour with few dark hairs on the upper part of body and tail. The amount of dark hair can be different for different cats. We had only two red, probably sunshine, kittens, with a brigthing stunning red colour. We have this sunshine colour in agouti, with and without the gene inibitor I for the silver colour. Until now this colour was named Golden when it appears without the silver, like the colour know for the Persian Cats. The colour with silver is usally called bimetal. The sunshine silver kittens born silver with slight shades of pinkish; the muzzle is very light with slight shades of pinkish too. In some months the silver black (blue/tortie) hairs on the back decreases and the sunshine colour increases. Description of sunshine tabby colour without silver The tipical rose colour of nose leather is always present! The typical lining of the tabby nose is not present in sunshine cats. It s a tabby cat with ground colour very warm; the kitten born with many base colour (black/blue/tortie) hairs; with age the based colour hair became less and can disappear and the cat shows many warm apricot-reddish hairs with tabby pattern and few dark hairs. The under parts are lighter. The tufts are light, almost white. 4

5 The paw pads are according with the base colour (black, blue, tortie) in cats without white. Eyes rims black/blue/tortie. Any amount of white is allowed. Description of sunshine silver tabby (bimetal) The tipical rose colour of nose leather is always present! The typical lining of the tabby nose is not present in sunshine cats. The cat is a silver cat, so the base of hair is white except in the sunshine hairs which usually are sunshine along all hair. The cat appears like it was divided in two along the body and its legs. To explain.. like a blue abyssinian. Upper parts are darker than the under parts. Muzzle, chin, under parts are almost white with tabby marking warm apricot, whitout any black/blue/tortie hairs. Front and rear legs are longitudinally divided in two side: the inside is clearly lighter than the outside. The ouside is the only one with black hairs. 5

6 The under of tail is light too Paw pads on the colour base of cat (Black/blue/tortie). Tufts in the ears almost white. Eyes rims black/blue/tortie. The kittens born dark and with age the colour changes like in pictures at bottom. 6

7 Any amount of white is allowed. Silver carrier sunshine Make attention: all silver cats which are carrier of sunshine have some patches reddish until at the base of hair. So they are silver tabby not sunshine tabby, nose leather like a normal tabby, but show like in those pictures some patches on the upper parts. 7

8 Names of colours I propose to put the name sunshine for this new colour. We can have Brown/blue/tortie sunshine tabby for the cats without the gene inibhitor and Black/blue/tortie sunshine silver tabby for the cats with the inibithor gene, because the gene is always the sunshine one. Those colours can be in blotched, mackerel and spotted variety, with or without white. The same colours can be in cscs variety for the Neva Masquerade. The eye colour does not depend on the gene sunshine so, with exception of Neva cats, all eye colours are admitted and, for sunshines silver ones, green eye colour is preferred. Neva sunshine cats can only have blue eyes. Because colour and pattern of coat isn t so important in Siberian cats (only 5 point) we can admit some variability in distribution of sunshine and base colour (Black, blue, tortie) We don t have at this moment any sunshine smoke or non agouti, but we breed for. That isn t so easy because many Siberian cats are Agouti. That is very interesting to see if, like the amber, those cats have the full color nose leather and ghost marking. Pictures I put some pictures of the same cat, black sunshine silver tabby blotched, during different ages,to see the evolution of his colour. The cat is a boy registered in AfeF. You can see that the kitten born in base colour (black in this case) with some shadows of sunshine,but he looks yet like a silver one. 8

9 The nose is rose, the paw pads are black. The legs near his feet look like white, but isn t a true white, after, with the time, the sunshine colour will appear. 2 days old 2 days old front 6 days 9

10 3 weeks 4 weeks 40 days 10

11 8 weeks 12 weeks 4 months old 11

12 8 months old front 8 months side 10 months front 12

13 10 months side Eleonora Ruggiero PS Please don t forward or copy this document without my name and . 13