Basic Bengal Cat Genetics

Traditionally the various coat color and effects are described in alphabetical order by Locus (location) but I find this order more helpful as it builds from the skin up.

B Locus: Primary Color

Black = B - Dominant - if a cat receives this gene from one of it's parents, the cat's primary color is black.
Chocolate = b - Recessive to B
Cinnamon = bl - Recessive to B, b

Most Bengals have black as their primary color. The colors Chocolate and Cinnamon are recessive colors that exist in the breed. A cat can carry Chocolate or Cinnamon and not exhibit the color so it is important to know a breeding cats genetics. If two cats are bred that carry for Chocolate, there is a chance of the kittens being Chocolate. If two cats are bred that carry for Cinnamon, there is a chance of the kittens being Cinnamon. Chocolate and Cinnamon are not recognized colors in some registration organizations and cannot be shown there. For a cat to be chocolate or cinnamon he or she must receive the gene from both parents. For the colors Blue, Lilac and Fawn please see the D Locus.Chocolate, b, is recessive to black. Chocolate is not recognized in most registries of the Bengal cat. Cinnamon, bl, is recessive to both black and chocolate. The pawpads and the tail tips are Chocolate and Cinnamon. This is one of the main ways to identify that a cat is not a brown/black tabby.

C Locus: Color Exhibition (The Full Color Locus)

C = Full Color - Dominant
cs = Colorpoint Siamese (the gene that causes Seal Lynx Point) - Recessive to C
cb = Colorpoint Burmese (the gene that causes Seal Sepia) - Recessive to C, incompletely dominant to cs
ca = Blue eyed Albino - Recessive to C, cs, and cb (ca/ca cats will be deaf)
c = Pink eyed Albino - Recessive to C, cs, and cb

You will note that there is no gene listed for Seal Mink. Seal Mink is caused by the combination of cs and cb genes. A Seal Mink receives Seal Lynx Point from one parent and Seal Sepia from the other. Just like other recessives a cat can carry the genes and not display them. Bengals carrying for "snow" are quite common and surprise white kittens can show up from two brown marbled or brown spotted cats. Both cs and cb are an albino variant found in the Siamese and Burmese breeds. True albino come in two forms, blue eyed and pink eyed. An albino Bengal will not display a pattern even if it has the Agouti gene. Albino cats often have a number of health related issues including vision problems, skin problems, and sensitivity to light. Another form of albinism is called leucistic, this is the condition that causes white tigers and lions with naturally colored eyes. A number of animal species produce occasional leucistic individuals.

A Locus: Agouti Banding (the ASIP gene)

Agouti (domestic) = A - Dominant - Pattern Displays
Agouti (ALC) = Apb - Dominant - Pattern Displays, Comes from the Centerwall ALC [PICTURE] [subspecies unknown]
Agouti (ALC) = A2 also called H1 by Dr. Christopher Kaelin - Dominant - Pattern Displays, From ALCs Taro [PICTURE]and Kabuki [P.b.chinesis] [PICTURE]
Agouti (ALC) = H2 Dominant, Comes from ALC Art Decco [subspecies unknown] [PICTURE]
Agouti (ALC) = H3 Dominant
- Another ALC Agouti gene that comes down from Taro [PICTURE], a hybrid of two different ALC subspecies.
Agouti (ALC) = H4 Dominant - Comes from ALC Stoney [subspecies unknown] [no pictures exist and subspecies unknown]
Agouti (ALC) = H5 Dominant - Comes down from ALC Phantom [PICTURE] who was wild caught frim the Himilayan Mountains making him P.b.horsfeildi
Non Agouti = a - Recessive - Pattern Does Not Display

This is the gene that determines if the tabby pattern will display or not. All Spotted or Marbled Bengals are Agouti/A - the pattern displays. However an all black Bengal, a Melanistic, is Non Agouti - the pattern does not display and the primary color, Black, is seen everywhere. Non-agouti is recessive and a cat must receive the gene from both parents for the pattern to be prevented from displaying. The gene can hide for several generations in a line. The Apb gene is a fairly recent discover and when combined as Apb/a it produces the "Charcoal" pattern. This gene comes down to Bengals from an ALC ancestor. It should be noted that as of 9/4/2016+ six different Agouti (ASIP) proteins have been identified that cime down from the ALC including A2.

To Read the White Paper on ALC Agouti genetics Click Here

Dr. Kaelin's ALC Research Slide

Another interesting paper on pattern genetics

E Locus: The Extension Gene (sometimes called the amber gene)

Extension = E - Dominant -Full Extension
Non Extension = e - Recessive - Non-extension

The Extension gene (red factor) has two alternative states (alleles). The dominant allele E produces black pigment (Eumelanin) in the coat. The recessive allele e produces a larger amount red pigment (Phemelanin) in the cat. It was once believed to be the source of "sorrel" coloring in Bengals but this theory has been disproven by genetic testing. The source of sorrels is unknown but it is currently being researched.

Wide Band Locus: Agouti Banding Variable

Wide Band = Wb - Dominant
Not Wide Band = wb - Recessive

Wb means that the agouti banding is made wider, thus more uniform and not as "ticked" looking. It is not known if this is a gene perse or a group of polygenes at this time. The wide band polygene affects the Agouti portions of the shaft where the emelanin (black) is turned off making them wider, sometimes so wide that the additional affects of the Agouti banding are pushed off the shaft giving the shaft a single color. It may be the source of the "clear coats" we see in the Bengal Breed. While this gene is covered in the book "Robinson's Genetics for Cat Breeders and Vetrinarians" it is not throughly examined in Bengals. There appears to be a relationship between the :clear coat" we see and some Bengals and the Wide Banding Variable it may also be what is called a "short tight coat" where the shaft of the fur is shorter and therefore lending itself having the Agouti banding pushed off the end of the shaft.

Mc Locus: Pattern Flow

Mackerel Tabby = Mc - Vertical Flow
Classic Tabby = mc - Circular Flow
Horozontal Tabby = mz - Horizontal Flow

A Mackerel Tabby pattern means the flow of the cats pattern is more vertical, up and down. This is where the vertical barring can come from. The Classic Tabby pattern means the flow of the pattern is circular on the body of the cat. Many Bengals have the pattern flowing in a circular manner on their sides. But where does the Horizontal Flow we see in the Asian Leopard Cat and many champion bengals come from. There are two theories:1.) The gene combination Mcmc creates Horizontal Flow. The problem with that theory is you don't see Horizontal Flow in any other breeds that don't use some form of leopard cat for their foundation2.) A new theory is that there is another gene being labeled mz that comes from the Asian Leopard Cat, and it is found on the same Locus. If this theory is true it may be the gene that makes the Horizontal Flow we strive for, and mzmz may be what makes some of the cutting edge cats so great.

Sp Locus: Pattern Interruption (the Taqpep gene)

Interrupted Pattern = Sp - Dominant - The pattern is interrupted producing "spots"
Uninterupted Pattern = sp - Recessive - The pattern is continuous creating a "marbled" effect

This is where our spots and marbles come from. Little is know about the genetics that make the differences in the spots at this time. Clearly there is a genetic piece causing round spots, arrowhead spots, two color rosettes, two color arrowhead rosettes and paw print rosettes. The marble gene is the same genes that causes the King Cheetah pattern.

How the tabby got it's blotches

T Locus: Ticking Locus

Ticked = T - Dominant - Agouti Band covers all but the base of the shaft
Not Ticked = Ta - Recessive - Agouti band pushed off the shaft of the hair

Ticking contributes to the intensity and contrast of the pattern by determining how much of the shaft is the base color (Black, Chocolate or Cinnamon). A highly Ticked cat will only have a narrow Agouti yellow band at the base of the shaft in the pattern. While T is dominant not receiving the gene from both parents does reduce the intensity indicating that the dominance may be incomplete. A cat that is TaTa will not show the Agouti pattern because the primary color is pushed off the shaft (like an Abyssinian).

I Locus: Inhibitor (also called the Silver gene)

Color Inhibited = I - Dominant (incompletely dominant to i)
Color Not Inhibited = i - Recessive

This gene affects the display of the yellow pigment on the Agouti banding by suppressing it. Working in tandem with the Agouti gene suppressing the production of phaeomelanin pigment (yellow/red), it has little or no effect on the emelanin pigment (black) production. With no production of phaeomelanin the shaft is left only with whatever emelanin production is occuring. If there isn't any, the shaft is white, if there are trace amounts the shaft is gray. The end result is that the shaft of the hair will look gray or white while tipped with the primary color (preferably black). This gene is dominant and only one parent needs to carry the gene for it to express. This is a very difficult gene to work with however and the color inhibition may be incomplete. In some cases break though of the phaeomelanin (yellow/red) occurs (Robinson's 142). This seems to only happen in silver cats that have one Inhibitor gene from one parent, and a Non-inhibitor gene from the other parent. This suggests that perhaps while the Inhibitor gene is dominat it may be incompletely dominant, or that there is a limit to the amount of phaeomelanin (yellow/red) it can supress when not homozygous.The resul is that by allowing the yellow to brown pigment to display the cat has what is called tarnish. Tarnish is very undesireable.

To Read the White Paper on Silver genetics Click Here

D Locus: Color Density

Dense Color = D - Dominant
Diluted Color = d - Recessive

This gene affects how the color cells in the shaft of the hair are dispersed. Normally the color cells are evenly distributed along the shaft of the hair, this is Dense Color and it is what we see in most Bengals. However if the color cells in the shaft of hair clump together they don't demonstrate the full coloring of the primary color making the shaft look "frosted" properly called Dilute. To be dilute the cat must receive the recessive d from both parents as dd ... DD and Dd will not show the diluted or frosted appearance. This is where the Bengal colors Blue, Lilac and Fawn come from. Blue is actually diluted Black, Lilac is actually diluted Chocolate, and Fawn is actually diluted Cinnamon.

O Locus: Orange

O = Orange - Dominant
o = Not Orange
- Recessive

Orange is the elimination of all eumelanistic (Black) pigment by converting the proteins into phaeomelanin (yellow). It comes from the Torbie influence used as an early outcross in the Bengal breed. This is not to be confused with rufousing. It is sex linked carried on the X chromosome. Females may exhibit the full Torbie or Calico, males will be all orange except in rare instances of non-disjucntion of the zygote. The Orange gene is not common but it has surfaced in the breed from time to time.

Mi Locus: Mica Glitter

Non-glittered = Mi - Dominant
Glittered = mi - Recessive

This gene is still partially theory. It affects just the tips of the hair shaft. In the recessive form, mi, when we look at the hair shaft under a powerful microscope we see what appear to be small flecks of Mica, a very reflective mineral, embedded in the tip of the hair shaft. We hope to post pictures of this effect on this page in the future. This gene did not come from the Asian Leopard Cat but rather from a domestic cat used by Jean Mill in her early breeding program. Another form of glitter runs the full length of the shaft, please see the Sa Locus for more information on that glitter type.

Sa Locus: Satin Glitter

Sa = Non-Satin - Dominant
sa = Satin - Recessive

This gene is still very much in the theory phase. This gene is seen in several species. Inter-species genetic comparison is common. Many mammals are genetically similar and traits found in one species may also crop up in another. The satin gene is well documented in some rodent species including mice and rabbits. It is also believed to be in Bengals coming from some of the domestic cats that were used as outcrosses in the Bengal such as Siamese, Burmese, Ocicat and Egyptian Mau. This gene creates little bubbles of air in a sheath that surrounds the full length of the follicle. These air bubbles catch and refract the light giving the coat a glittered effect which, while similar in some respects to the Mica Glitter, it is also very different. This gene also makes the shaft of the hair very smooth and gives the cats coat a very soft and silky feel. The more satin shafts in the coat the silkier and softer the fur.

L Locus: Hair Length

L = Short Hair- Dominant
l = Long Hair- Recessive
(older designation)
m1 = Long Hair- Recessive
(found in Ragdolls and Siberians)
m2 = Long Hair- Recessive
(found in Norwegian Forest Cats, Siberians and Tiffanies)
m3 = Long Hair- Recessive
(found in Ragdolls and Maine Coons
m4 = Long Hair- Recessive
(found in all breeds of cat including Ragdolls, Maine Coons, Norwegian Forest Cats, Siberians and Tiffanies)

The long hair gene doesn't crop up very often in the Bengal breed, but it is out there. Bengals are intended to be short hair but the occasional long hair kitten crops up. They are gorgeous, loving and make a great friend. They are not currently showable and are usually only available as beautiful pets. A small group of breeders in Europe have decided to work with the long hair gene under the new breed name Cashmeres. Research on the gene has shown that there are five different variations of this gene. New research has found that there are four different variations of long hair in domestic cats. Because a number of "pound cats" were used early in the Bengal breed the long hair gene has been found in some lines of Bengals. It should also be noted that a number of Abyssians have also been used and this is another possible source of long hair due to their relationship to Somalis. The only genetic difference between Abyssians and Somalis is the long hair gene. Many Somali breeders also breed Abyssians as well and use a "variant" male, a short haired male that carries for long hair, to produce kittens of both breeds. To judge whether or not a cat is a long hair or not look at the hair at the base of the tail. If the hair at the base of the tail is long the cat has one of the long hair genes from both parents. It should be noted that the long hair genes must be of the same type for long hair to display.

To Read the White Paper on Long Hair genetics Click Here

 

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