AGOUTI gene A

Gene A is responsible that each hair gets yellow banded.
In all tabby varieties - except the red tabby - gene A is necessary that the underlying tabby pattern which is present in each cat gets visible to you.
You find this gene also in the silver tabbies, in the goldens and colourpoint tabbies.

an agouti hair with the yellow banding

Non-Agouti gene a

Gene a is recessive to gene A. If a cat carries gene a double (aa) then its coat colour gets solid und you cannot see the underlying tabby pattern which is present in each cat.
Gene a is called to mask the tabby pattern.
When you look on new born kittens, f.e. black kittens, in the first days you can see the underlying tabby pattern. These tabby stripes dissappear when the kitten is growing, if it does not carry gene A, but carries aa.

Gene combinations

AA	homozygous agouti the tabby pattern gets visible
Aa	heterozygous agouti the tabby pattern gets visible
aa	homozygous non-agouti coat colour gets solid, the tabby pattern cannot be seen

How does gene A operate on the various colours ?

Non-diluted colours				Diluted colours
colour	gene combination	colour	gene combination	colour	gene combination	colour	gene combination
black	aa B- D- oo	black tabby	A- B- D- oo	blue	aa B- dd oo	blue tabby	A- B- dd oo
Gene A must be present only once to see the tabby pattern already. For "A-" you may put AA or Aa.				For "B-" you may put BB, Bb, Bb^l. For "D-" you may put DD or Dd.
chocolate	aa b- D- oo	chocolate tabby	A- b- D- oo	lilac	aa b- dd oo	lilac tabby	A- b- dd oo
For "b-" you may put bb or bb^l.
cinnamon	aa b^lb^l D- oo	cinnamon tabby	A- b^lb^l D- oo	fawn	aa b^lb^l dd oo	fawn tabby	A- b^lb^l dd oo
red self	male: aa -- D- OY or A- -- D- OY female: aa -- D- OO or A- -- D- OO	red tabby	male: aa -- D- OY or A- -- D- OY female: aa -- D- OO or A- -- D- OO	cream	male: aa -- dd OY or A- -- dd OY female: aa -- dd OO or A- -- dd OO	cream tabby	male: aa -- dd OY or A- -- dd OY female: aa -- dd OO or A- -- dd OO
For "--" you may put BB, Bb, Bb^l or bb, bb^l or b^lb^l. Remember that gene O colours all hairs to red regardless their colour.				Remember also that between a red self and a red tabby is no difference.
black tortie	aa B- D- Oo	black tortie tabby	A- B- D- Oo	blue tortie	aa B- dd Oo	blue tortie tabby	A- B- dd Oo
Note that all torties are females.				Tortie tabbies are often called torbies.
chocolate tortie	aa b- D- Oo	chocolate tortie tabby	A- b- D- Oo	lilac tortie	aa b- dd Oo	lilac tortie tabby	A- b- dd Oo
cinnamon tortie	aa b^lb^l D- Oo	cinnamon tortie tabby	A- b^lb^l D- Oo	fawn tortie	aa b^lb^l dd Oo	fawn tortie tabby	A- b^lb^l dd Oo
You can imagine that it is very difficult to see the red patches in a rich coloured cinnamon tortie or see the cream patches in a dull coloured fawn tortie.

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

You have a red tabby female, but don't know if she is carrying Agouti or not.

One way to find out would be to mate her with a black male.
We assume, that both the female and the male don't carry chocolate or cinnamon. Our female can have the following genetic background:
aa BB D- OO or
Aa BB D- OO or
AA BB D- OO
Our black male has the genetic background:
aa BB D- oY

Eurocatfancy

Gene A: Agouti

AGOUTI gene A

Non-Agouti gene a

Gene combinations

How does gene A operate on the various colours ?

Non-diluted colours

Diluted colours

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

You have a red tabby female, but don't know if she is carrying Agouti or not.

Example 1