Chapter 11: Colour genetics

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Chapter 11 Colour genetics

• Hair types
• Colour types and colour genes
• Colour genes and biochemical function
• Examples from different domestic animals

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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 mm Hair
N- Hairless nn
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Examples of hair types
Long hair
Wire haired
Mole guard hair
Hairless
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Colour types in mammals and colour genes

• Melanin is the stain of the hair Eumelanin ?
  black and brown Phaeomelanin ? yellow and red
• Air bubbles ? White
• Melanin is produced in a cell type, called
  melanocytes

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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

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Colour genes and biochemical function
The genes can be divided into the following
groups

• Part of the melanin synthesis (biochemical
  synthesis)
• Regulate melanin production (hormonal)
• Regulate the morphology of the melanocytes
• Regulate number of melanocytes

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Colour genes biochemical function
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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
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Colour genes in Danish cattle breeds

Dominant Recessive Black
E- Red ee Uniform S-
Spotted ss White head H-
Uniform hh
Black white Red Danish Hereford
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Colour genes in the horse

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Colour genes in the horse

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Colour genes in the dog

Dominant Recessive Black and
tan at- Red aa Black B-
Brown bb Dark C- Light
cch cch Black D- Silver
dd Black E- Red (yellow)ee
Uniform mm Merle M-
Labrador
Airedale
Tibetan
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Colour genes in mink

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Colour genes in mink

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Colour genes in cats

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Colour genes in other species

• Sheep
• Rabbit
• Mouse