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Gene O: Orange

 
Eurocatfancy
Genetic terms in cats
Genome of the cat
Dominance of genes
Cat Breeding techniques
Crossing Table 1
Crossing Table 2
Crossing Table 3
Gene A: Agouti
Gene B: Black
Gene C: Full colour
Gene D: Diluted
Gene Dm: Dilute modifier
Gene Fd: Folded ears
Gene I: Inhibitor
Gene L: Shorthair
Gene Mc: Mackerel
Gene O: Orange
Gene S: Piebald spotting
Gene W: White
Gene XY: Sex
Quality Points for Cats

 

Gene O: Orange

Gene O, o

ORANGE gene O

Gene O is responsible that a black, chocolate or cinnamon coloured coat gets red. This gene colours all hairs to red.
It is dominant over its companion o.
But gene O has a speciality, it is sex linked to the chromosome X. You remember, a male has the chromosome pair XY, a female has XX. As gene O is linked to the X-chromosome, a red male has the gene pair OY and only passes one gene O to his litter, a red female has the gene pair OO and can pass twice gene O to her litter.

Non-orange gene o

Consequently a male which has the gene pair oY has a black coat, a female which has the gene pair Oo is tortie.
A female which has the gene pair oo is of course black.

"dark" colour diluted colour
red cream
black tortie blue tortie
chocolate tortie lilac tortie
cinnamon tortie fawn tortie

Possible gene combinations

OY red male Note that a red male can only pass one gene O for red coat colour to his offspring, while a red female can pass twice the gene O. If the second gene Y from a red male is passed to his offspring, they will be boys.
OO red female
Oo tortie female

Colours with red

Now - only with 3 genes - we know already the genetic fingerprints of a lot of colours.

non diluted colour gene combination diluted coat colour gene combination
red male BB DD OY bb DD OY female BB DD OO bb DD OO cream male BB dd OY bb dd OY female BB dd OO bb dd OO
BB Dd OY bb Dd OY BB Dd OO bb Dd OO
Bb DD OY bbl DD OY Bb DD OO bbl DD OO Bb dd OY bbl dd OY Bb dd OO bbl dd OO
Bb Dd OY bbl Dd OY Bb Dd OO bbl Dd OO
Bbl DD OY blbl DD OY Bbl DD OO blbl DD OO Bbl dd OY blbl dd OY Bbl dd OO blbl dd OO
Bbl Dd OY blbl Dd OY Bbl Dd OO blbl Dd OO
black tortie female BB DD Oo blue tortie female BB dd Oo
BB Dd Oo
Bb DD Oo Bb dd Oo
Bb Dd Oo
Bbl DD Oo Bbl dd Oo
Bbl Dd Oo
chocolate tortie female bb DD Oo lilac tortie female bb dd Oo
bb Dd Oo
bbl DD Oo bbl dd Oo
bbl Dd Oo
cinnamon tortie female blbl DD Oo fawn tortie female blbl dd Oo
blbl Dd Oo

My red cat has so many stripes

Is there any difference between a red and a red tabby ?
Particularly not. Red and red tabby cats are the same. Red self is the result of selective breeding. There are taken red tabby - mostly blotched - which show very little pattern to breed Red selves. The more often this procedure is repeated the more the pattern will get blurred, so that in the end the tabby pattern cannot be seen. You can see in the Red selves that they are tabbies if you look at their face, where they show the "M" on the forehead, mostly you will also find the most upper ring on the front legs to be present.
Selective breeding is also necessary to avoid the white locket on the throat and the white patch on the tail tip. The older the cats are, the larger is usually the white patch on their tail tip.
From the phenotype you cannot see if your red tabby cat is an agouti tabby or not, because the Agouti gene which turns "black" hairs into yellow banded hairs cannot fully operate on orange hairs. This fact is discussed in the lesson about the Agouti gene.

All cats which are not red carry the gene combination oo.

coat colour gene combination coat colour gene combination remarks
black B- D- oo blue B- dd oo Note: For "B-" you can put BB, Bb or Bbl.
For "D-" you can put DD or Dd.
The "-" indicates that it cannot be said for sure which gene is present.
chocolate b- D- oo lilac b- dd oo Note: For "b-" you can put either bb or bbl.
cinnamon blbl D- oo fawn blbl dd oo -
As "oo" is present by default in all non-orange cats this gene pair will be omitted in future, that does not mean that it is not present. This is only done because of readability.

 

How can this theoretical knowledge be used for the breeding practice ?

Example 1:

Think about the following gene combinations:

  • BB OO
  • Bb OO
  • bb OO
  • b bl OO
  • bl bl OO

All these cats - females - are red or cream, if they have dd. On behalf of the gene O you can see the meaning of Mimic gene, another mimic gene is the gene W responsible for an overall white coat colour. If you want to find out if your cat carries black, chocolate or cinnamon you must have a closer look at the pedigree or do a test mating with your cat. For example, if you want to know if your cat carries chocolate you have to mate her with a chocolate male.

You want to breed a red female.

Example 2: We cross a red male with a black female

Our male has the gene combination: BB D- OY
Our female has the gene combination: BB D- oo

  male
BDO BDY B-O B-Y
female BDo BB DD Oo
black tortie females
BB DD oY
black males
BB D- Oo
black tortie females
BB D- oY
black males
B-o BB D- Oo
black tortie females
BB D- oY
black males
BB -- Oo
black or blue tortie females
BB -- oY
black or blue males

With these cats red females will never be produced. There will be also no red males born. There will be born only tortie girls.

Example 3:

We change the colours between the male and the female. We cross a black male with a red female.
Our male has the gene combination: BB D- oY
Our female has the gene combination: BB D- OO

  male
BDo B-o BDY B-Y
female BDO BB DD Oo
black tortie females
BB D- Oo
black tortie females
BB DD OY
red males
BB D- OY
red males
B-O BB D- Oo
black tortie females
BB -- Oo
black or blue tortie females
BB D- OY
red males
BB -- OY
red or cream males

With this combination only red/cream males and tortie females will be born, There are still no red females born.
You will also not get a red female, if you use a tortie female. You can try it.

Example 4: We cross a red male with a black tortie female

Our male has the gene combination: BB D- OY
Our female has the gene combination: BB D- Oo

  male
BDO BDY B-o B-Y
female BDO BB DD OO
hurra !
red females
BB DD OY
red males
BB D- Oo
black tortie females
BB D- OY
red males
BDo BB DD Oo
black tortie females
BB DD oY
black males
BB D- oo
black females
BB D- oY
black males
B-O BB D- OO
once more
red females
BB D- OY
red males
BB -- Oo
black or blue tortie females
BB -- OY
red or cream males
B-o BB D- Oo
black tortie females
BB D- oY
black males
BB -- oo
black or blue females
BB -- oY
black or blue males

You will get red females only when both parent have red, that means at least the female must be a tortie which is crossed with a red male. Of course you will get red females when both parent are red.

 
[A] [B] [C] [cb & cs] [D] [Dm] [Fd] [I] [L] [Mc] [O] [S] [W] [XY]

 
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