Chapter 11: Colour genetics
• Hair types
• Colour types and colour genes
• Colour genes and biochemical function
• Examples from different domestic animals
Hair types
• Physical texture
• Ratio between under fur and guard hair
• Strength and durability of the fur
• Winter pelt and summer pelt
Hair types and genotypes Dominant Recessive Wire haired W- Straight haired ww Short haired L- Long haired ll Guard hair M- Mole mmHair N- Hairless nn
Colour types in mammals and colour genes
• Melanin is the stain of the hairEumelanin black and brownPhaeomelanin yellow and red
• Air bubbles White
• Melanin is produced in a cell type, called melanocytes
Important colour loci in domestic animals
• Agouti locus: A-locus • Brown locus: B-locus brown whelps • Albino locus: C-locus • Dilution locus: D-locus• Extension locus: E-locus yellow whelps • Pink eyed dilution locus: P-locus• X-linked Orange locus: O-locus
Colour genes and biochemical function
• Part of the melanin synthesis (biochemical synthesis)
• Regulate melanin production (hormonal)• Regulate the morphology of the melanocytes • Regulate number of melanocytes
The genes can be divided into the following groups:
Colour genes in Danish swine breeds
Dominant Recessive
Dominant white I- Coloured ii Black E- Red ee White belt B- Uniform bb
Yorkshire Landrace Hampshire Duroc
Colour genes in Danish cattle breeds
Dominant Recessive
Black E- Red ee Uniform S- Spotted ssWhite head H- Uniform hh
Black & white Red Danish Hereford
Colour genes in the dog
Dominant Recessive
Black and tan at- Red aaBlack B- Brown bbDark C- Light cch cch
Black D- Silver ddBlack E- Red (yellow)ee Uniform mm Merle M-Airedale
TibetanLabrador
Colour genes in minkColour types, single
Mutant nameMutant genotype
Wild type, Standard
White Albino, red eyed cc CC
Hedlund White, deaf
hh HH
Grey Aleutian, bluish aa AA
Silver Blue, grey pp PP
Steel Blue psps PP
Brown Royal Pastel bb BB
Moyl mm MM
American Palomino
kk KK
Bicoloured Black Cross Ss ss