Colour Genetics

Colour Genetics

Guest Book

Dams Across Sires Below	Black Tortie	Black Tortie (Carrying Dilute)	Blue Tortie (Dilute)
Red	Black Males Red Males Red Females Tortie Females	Black Males Red Males Red Females Tortie Females 50% kittens carry dilute	Black Males Red Males Red Females Tortie Females All kittens carry dilute
Red (Carrying Dilute)	Black Males Red Males Red Females Tortie Females 50% kittens carry dilute	Black Males Blue Males Red Males Cream Males Red Females Cream Females Tortie Females Blue Tortie Females 50% non dilute kittens carry dilute	Black Males Blue Males Red Males Cream Males Red Females Cream Females Tortie Females Blue Tortie Females All non dilute kittens carry dilute
Cream (Dilute)	Black Males Red Males Red Females Tortie Females All kittens carry dilute	Black Males Blue Males Red Males Cream Males Red Females Cream Females Tortie Females Blue Tortie Females All non dilute kittens carry dilute	Blue Males Cream Males Cream Females BlueTortie Females

You will see from the table below that mating 2 cats carrying Dilute will result in 25% Black, 25% Blue and 50% Black carrying Blue

Dams Across Sires Below	Black	Black (Carrying Dilute)	Blue (Dilute)
Black	Black Males Black Females	Black Males Black Females 50% kittens carry dilute	Black Males Black Females All kittens carry dilute
Black (Carrying Dilute)	Black Males Black Females 50% kittens carry dilute	Black Males Blue Males Black Females Blue Females 50% non dilute kittens carry dilute	Black Males Blue Males Black Females Blue Females All non dilute kittens carry dilute
Blue (Dilute)	Black Males Black Females All kittens carry dilute	Black Males Blue Males Black Females Blue Females All non dilute kittens carry dilute	Blue Males Blue Females

Dams Across Sires Below	Black	Black (Carrying Dilute)	Blue (Dilute)
Red	Black Males Tortie Females	Black Males Tortie Females 50% kittens carry dilute	Black Males Tortie Females All kittens carry dilute
Red (Carrying Dilute)	Black Males Tortie Females 50% kittens carry dilute	Black Males Blue Males Tortie Females BlueTortie Females 50% non dilute kittens carry dilute	Black Males Blue Males Tortie Females BlueTortie Females All non dilute kittens carry dilute
Cream (Dilute)	Black Males Tortie Females All kittens carry dilute	Black Males Blue Males Tortie Females BlueTortie Females All non dilute kittens carry dilute	Blue Males Blue Tortie Females

Dams Across Sires Below	Red	Red (Carrying Dilute)	Cream (Dilute)
Black	Red Males Tortie Females	Red Males Tortie Females 50% kittens carry dilute	Red Males Tortie Females All kittens carry dilute
Black (Carrying Dilute)	Red Males Tortie Females 50% kittens carry dilute	Red Males Cream Males Tortie Females Blue Tortie Females 50% non dilute kittens carry dilute	Red Males Cream Males Tortie Females Blue Tortie Females All non dilute kittens carry dilute
Blue (Dilute)	Red Males Tortie Females All kittens carry dilute	Red Males Cream Males Tortie Females Blue Tortie Females All non dilute kittens carry dilute	Cream Males Blue Tortie Females

Dams Across Sires Below	Black Tortie	Black Tortie (Carrying Dilute)	Blue Tortie (Dilute)
Black	Black Males Red Males Black Females Tortie Females	Black Males Red Males Black Females Tortie Females 50% kittens carry dilute	Black Males Red Males Black Females Tortie Females All kittens carry dilute
Black (Carrying Dilute)	Black Males Red Males Black Females Tortie Females 50% kittens carry dilute	Black Males Blue Males Red Males Cream Males Black Females Blue Females Tortie Females Blue Tortie Females 50% non dilute kittens carry dilute	Black Males Blue Males Red Males Cream Males Black Females Blue Females Tortie Females Blue Tortie Females All non dilute kittens carry dilute
Blue (Dilute)	Black Males Red Males Black Females Tortie Females All kittens carry dilute	Black Males Blue Males Red Males Cream Males Black Females Blue Females Tortie Females Blue Tortie Females All non dilute kittens carry dilute	Blue Males Cream Males Blue Females BlueTortie Females

Dams Across Sires Below	Red	Red (Carrying Dilute)	Cream (Dilute)
Red	Red Males Red Females	Red Males Red Females 50% kittens carry dilute	Red Males Red Females All kittens carry dilute
Red (Carrying Dilute)	Red Males Red Females 50% kittens carry dilute	Red Males Cream Males Red Females Cream Females 50% non dilute kittens carry dilute	Red Males Cream Males Red Females Cream Females All non dilute kittens carry dilute
Cream (Dilute)	Red Males Red Females All kittens carry dilute	Red Males Cream Males Red Females Cream Females All non dilute kittens carry dilute	Cream Males Cream Females

Simple Inheritance
Named after the studies of Gregor Mendel, simple inheritance relates to a trait governed by a single gene.

In cats, the inheritance of black and blue is an example. Genes on the autosomes (the chromosomes other than the X and Y sex chromosomes) are inherited in pairs, one copy from each parent.

If a cat inherits 2 blue genes, it will be blue. If it inherits 2 black genes it will be black. If it inherits 1 black gene and 1 blue gene it will be black but can pass on the blue gene to its offspring.

The black gene is dominant - this gene will always be expressed (show up in the phenotype i.e. outward appearance) even if only 1 copy is present. The blue gene is recessive and will only be expressed if 2 copies are present.

A dominant gene is always expressed even if only one copy is inherited. A recessive gene is only expressed if two copies are inherited.

An animal where both copies of the gene are the same is homozygous for that trait. An animal where the copies are different is heterozygous for that trait.

The blue gene is recessive. It is only expressed if the cat didn't inherit a black gene. Blue cats are homozygous for the blue colour. Its genotype (genetic make-up) is the same as its phenotype unlike a black cat whose genotype can be either heterozygous or homozygous.

By convention, a dominant gene is shown in uppercase and a recessive gene is shown as the same letter, but in lowercase.

You will see from the table below that mating a blue (solid or tabby) cat to a black not carrying dilute (tabby or solid) all the resulting kittens will be black (tabby or solid) and whilst none will be blue they will ALL carry blue (dilute) This is the same for Cream as it is the dilute of Red as Blue is simply the dilute of Black.

	Black Homozygous Cat BB
	B	B
Blue Homozygous Cat bb
b	Bb	Bb
b	Bb	Bb

	Black Heterozygous Cat Bb
	B	b
Black Heterozygous Cat Bb
B	BB	Bb
b	Bb	bb

Tabby Patterns also have a dominant and recessive - Mackerel is Dominant and needs only one copy to express in the coat - Classic needs two to express in the coat. All cats carry two tabby patterns - so a Mackerel cat can carry Classic pattern but not the other way around.

Solid works like the dilute gene - you need two copies to be solid but you can have a tabby cat who carries solid.

Silver - the Inhibitor gene is again Dominant and needs a cat to have at least one copy for it to be a silver (or smoke in a solid cat) - because of this a cat cannot carry silver it must be silver to have silver offspring. A cat can however have two copies of the silver gene if both it's parents were silver there is a 25% chance that the cat is Homozygous (carries two copies) and will therefore only have silver offspring no matter what mating is done.

Red is another dominant colour as it influences the non-agouti gene. Non-agouti (solid colour) cats that also have the orange gene will turn out tabby. Even the so-called solid red (red self) cat has tabby markings, even though breeders are working to decrease the contrast between background and marking colours.

Here you see a table with the mating of a tortie female to a red male.
	*Genes from Tortie Female*
	O (Red)	o (Black)
Genes from Red Male
O (red) (X Chromosome)	OO (Red Female)	Oo (Tortie Female)
No Gene (Y Chromosome)	O- (Red Male)	o- (Black Male)

Here you see a table with the mating of a tortie female to a black male.
	*Genes from Tortie Female*
	O (Red)	o (Black)
Genes from Black Male
o (black) (X Chromosome)	Oo (Tortie Female)	oo (Black Female)
No Gene (Y Chromosome)	O- (Red Male)	o- (Black Male)