Basic Genetics Judges Seminar Albufeira May 2010
Who am I? • Ole Amstrup • Cattery name: DK Feles Grata • Breeding: Oriental shorthair preferably blotched tabby, with silver, in all colours and patterns. • How long: Since 1983
Who am I? • Why color genetics? • Because I once breed budgerigars! • Because I love mathematics!
To see a cat Some see a cat!
To see a cat • I see: a female cat genetic black color not diluted with white it’s a tortie mackerel tabby shorthair
To see a cat • I see: A - non agouti BB black D - not diluted LL shorthair Mc - mackerel Ss bi-colour xox tortie
To see a cat • A cat is ”built” of many different elements – a puzzle which can be joint together in many ways. • color • sex • pattern • hair lenght • etc.
What is the color of the cat about? Back to the basic! Felis Sysvestris Lybica
Original genetics The original model: AA BB CC DD ii LL McMc ss xy ww
Original genetics The original model: agouti black no dilution non silver short hair spotted no white no points no red AA BB CC DD ii LL McMc ss xy ww
Original genetics Before I start! Look at the pattern of the wild ! An agouti background and a pattern in a little darker tone.
Original genetics Most hairs is of this type (ticked or banded hairs): The pattern is areas of darker ticking on a lighter ticked ground The agouti ground The pattern
Original genetics Nature goes for the average We go for the extreme
What is the color of the cat about? Production of color pigmentation and the distribution of the pigment granules Some modifying factors
What is the color of the cat about? Production of melanine Different types (black, choc and cin.) Amount of melanines Normal Overproduction (non agouti /pattern) None (red) Distribution (dilution) Modification (amber)
What is the color of the cat about? Production of pheaomelanine Distribution (dilution) None (silver) Modification (rufism)
What is the color of the cat about? Pattern / modification of pattern original pattern (spottet/blotched) ticked (ticked tabby) wide band (shaded/tipped)
What is the color of the cat about? No production of pigment all white (the white colour) piebald spotting (the white spotting) gloves (SBI) white spots (??)
What is the color of the cat about? Reduction of pigmentetion normal burmese siamese ressecive white albino
What is the color of the cat about? The quality of the colour and pattern Polygenetic modifications
Genes Colour genes (color and pattern) Each gene controls one feature Can be dominant, recessive or partly dominant
Genes • Polygenes • A lot of ”small” genes work together • They work in different ways • “Qualitymakers” • Modifyers • Treshold characters
Chromosomes • Genes are placed on the chromosomes • There are several thousands genes on every chromosome • The color genes we know control one exact feature.
Chromosomes There are three different types of genes controlling one feature: dominant recessive partly dominant
Chromosomes • 18 pairs with two identical • 1 pair is not always identical X Y X X • X carries genes. • Y carries no genes. You can only deduct that this individual will be a male
Colour genetics • I will look at one feature at a time. • They can be combined later on.
B alleles – Black/brown colour B > b > bl Decides the shape of the euamelanin granules B = normal shape black b = oval shape chocolate bl = rod shape cinnamon
B alleles – Black/brown colour B > b > bl BB / Bb / Bbl Black bb / bbl Chocolate blbl Cinnamon .
B alleles – Black/brown colour B > b > bl BB the natural colour – only black MCO – NFO – SIB – TUV – RUS – KOR - SOK B and the b mutation – Black and chocolate BRI – PER/EXO – SBI – BUR B and the bl mutation – Black and cinnamon(sorrel) ABY – SOM B, b and the bl mutation – Black, chocolate and cinnamon Category IV – RAG – SNO – ACL – ACS – DRX – DRX – GRX
B genes – colourdistribution Distribution of B genes / B black – b chocolate black X black black (choc.) X black (choc.) 100% black 75% black ( 25/50), 25% choc.
B genes – colourdistribution Distribution of B genes / B black – b chocolate black (choc.( X choc. choc. X choc. 50% black / 50% choc. 100% choc.
The red colour The red color. The red color is sex linked. The gene is placed on the X chromosome. No eumelanin is prodcued, no matter the type. Black, chocolate and cinnamon colours can not be produced!.
The red colour Only phaeomelanin (the yellow/red color) is produced
The red colour I have chosen to mark this gene for orange/red as a variation of the normal X gene, as the placement of the red allele is at the X chromosome. X the normal coloured cat Xo red Y carry no genes This way I think it is more clear that the color is sex linked and the explanation about the outcome as a result of mating red/tortie cat is more clear. This is my way of seeing it – and not all share my opinion on this matter.
The red colour Xo blocks the production of eumelanine. Only phaomelanine will be produced. In order to work fully there must be two Xoin a female . In the male, who only has one X chromosome, one Xo gives a red male
Red mating – colour distribution Male: red Females: normal - tortie - red females: tortie red or tortie red males: normal normal or red red ½
Red mating – colour distribution Male: Normal Female: normal - tortie - red females: normal normal and tortie tortie male: normal normal and red red ½
Colour pigmentation The basic colurs Black BB / Bb / Bbl Black eumelanine Chocolate bb / bbl Chocolate eumelanine Cinnamon blbl Cinnamon eumelanine Red No eumelanine
Colour pigmentation The basic colurs black chocolate cinnamon red
Colour pigmentation The basic colurs Explanation to why there is no difference between a genetically black, chocolate or cinnamon based red! No eumelanine is produced to give the difference!!!
D allele - dilution DD / Dd controles the distribution of pigment granules in the hair. DD and Dd give an even distribution dd gives uneven deposit the hair appears lighter
D allele - dilution DD / Dd • cross section of a normal coloured hair (dense). • colour pigment evenly distributed in the hair • colour is black, choc., cinnamon
D - allele - dilution dd Diluted hair Colour pigment is placed in groups Light can pass through the hair The hair appears paler Uneven placement of pigment • black blue • choc. lilac • cinnamon fawn • red creme
D - allele - dilution dd Even though the pigment granules are distributed in an other way this will have no effect on the eyecolour.
”Mating” black [Bb Dd ] X lilac [bb dd] Distribution of B genes and D genes 50% black / 50% choc. 50% dense/ 50 diluted
”Mating” black [Bb Dd ] X lilac [bb dd] Distribution
Tabby patterns We have seen the tabby pattern of the wild! Two different shades of agouti In the tabby pattern is a higher production of eumelanine. Varying from almost the same level to an almost black hair.
Tabby patterns We have seen the tabby pattern of the wild! Two different shads of agouti In the tabby pattern is a higher production of eumelanine. Varying from almost the same level to an almost black hair.
Tabby patterns All cats have a tabby pattern!! But you cannot always see it!! The structure of the hairs. Is still there. When it can be seen, it is a coloured pattern / a darker agouti area on an (lighter) agouti background