Infos av Trollska, colour-genetics

Colours-Genetics

Have you ever surfed from one cat-homepage to another and this breeder were writing about their cat's genotype "Aa dd ii tt ww Ss ww oo". And now you wish to know what this breeder
like to let you know?
This example let you know that this breeder has a female cat in the colour blue tabby blotched with white. If you say WHY please read foward, I will tray to explain it to you.

First, I like to explain a few terms which you will see in this context:

phenotype	descripe how the cat looks like
genotype	are the hereditary information
allele	each individual has the same gene from the mother as from the father too, but it might be different in their effect (2 alleles)
dominat	If a gene is dominant over an other, it need only one allele for its effect (Aa, AA)
recessive	If a gene is recessive, this gene has to be pure-bred that you can see the effect of this gene, needs 2 alleles (aa)

Next, in this table you will find description of different genes which are relevant to
the Norwegian forest cats and their transmission genetics of the different colours:

gene	description	look - explanation
A	agouti	original coloured, Tabby, hair are broadely striped in black and yellowish brown	dominant
a	non-agouti	hair are unicoloured	recessive
D	non-dilution	dense pigmentation (black/ red)	dominant
d	colour-dilution	diluted pigmentation of the hair (blue/ cream)	recessive
I	inhibitor-gene	suppresses the pigmentation of different part of the hair (silver/ smoke)	dominant
i	normal pigmentation	without silver/ smoke	recessive
S	variegation-gene	variable white spots on the coat	dominant
s	not variegated	normal colour, without white spots on the coat	recessive
T	mackerel Tabby	mackerel Tabby pattern	dominant
t	blotched Tabby	blotched Tabby pattern	recessive
W	pure white	pure white cat with blue, yellow, green eyes or odd-eyed, this gene conceals all other coat-colour	dominant
w	normal colour	not a white cat, all other colour possible	recessive
O	red	changes black into red and this gene is sex-linked
o	normal colour	not red
	OO	red female
	OY	red male
	Oo	tortoiseshell female
	oo	black female
	oY	black male

AN EXAMPLE OF A BREEDING:

	female	male
phenotype	NFO fs 23	NFO n 09 22
genotype	Aa DD Ii ss Tt ww Oo	Aa Dd ii Ss tt ww oY

m/f

EXPLANATION OF THE TABLE BELLOW:
about 75% of the cats are tabby, 25% are unicoloured cats
tabby-cats will be half blotched and half mackerel
all cats will have dark coloured coat (red or black) = without dilution
all variations with or without silver/ smoke are possible 50:50
all variations with or without white are possible also 50:50
no pure white cats
tortoiseshell and black females and black and red males

Now, of this statements bellow are all different variation possible,
in different probability :
black tabby mackerell/ blotched with/ without white and with/without silver
black with/ without white and with/without smoke
red male with/ without white and with/without silver
black tortoiseshell female with/ without tabby, with/ without white and with/without smoke

This cat couple had in two litters follow kitten:

sex	phenotype	colour	genotype
1. litter
F	f 09 23	black tortoiseshell tabby mackerel with white	A- D- ii Ss Tt ww Oo
F	n 23	black tabby mackerel	A- D- ii ss Tt ww oo
F	fs 22	black tortoiseshellt silver tabby blotched	A- D- Ii ss tt ww Oo
M	ns 09	black smoke with white	aa D- Ii Ss -t ww oY
2. litter
F	f 09	black tortoiseshell with white	aa D- ii Ss -t ww Oo
F	ns	black smoke	aa D- Ii ss -t ww oo
F	fs 23	black tortoiseshellt silver tabby mackerel	A- D- Ii ss Tt ww Oo
M	n 22	black tabby blotched	A- D- ii ss tt ww oY
M	d 09 22	red tabby blotched with white	A- D- ii Ss tt ww OY

EVERTHING ALLRIGHT?!... otherwise contact me and we can discuss further more

I know that I could write a big book about this topic.
But I just like to give you an general idea about this subject.