Lecture 9: Set 3 - Other Coat Colors and Patterns

What are three other coat-color dilution genes?

Champagne, pearl, and silver.

What are four white spotting or pattern genes?

Appaloosa spotting and pattern-1, dominant white, tobiano, and sabino 1.

What is the difference between genotype and phenotype?

Genotype = genetic code; phenotype = what the horse looks like.

Does every horse have all the coat-color genes discussed?

No. Most horses do not possess all of them.

What does the extension gene control in coat color?

Red versus black base color.

What does the agouti gene control in coat color?

Whether black pigment is uniform or restricted to the extremities.

What is the difference between a base color and a white spotting pattern?

Base color is the underlying color; spotting genes add white patterns.

What does a dominant gene generally do?

It can be expressed when paired with a different allele.

When can a recessive trait generally be expressed?

When two recessive alleles are present.

What does Ccr do to pigmentation?

It reduces pigmentation, creating a lighter coat.

What is the difference between dun and cream dilution?

Dun uses the dominant D allele; cream dilution uses the C/Ccr alleles.

What is the difference between roan and grey?

Roan mixes white hairs with base-color hairs; grey progressively lightens with age.

Which gene masks the expression of other coat-color genes?

The dominant grey allele, G.

Which coat-color gene produces grullo?

Dun (D) on a black base color.

Which coat-color gene produces buckskin?

Cream dilution: one dilution on a bay base.

Which coat-color gene produces palomino?

Cream dilution: one dilution on a red base.

Which coat-color gene produces perlino?

Cream dilution: two dilutions on a bay base.

Which coat-color gene produces cremello?

Cream dilution: two dilutions on a red base.

What genotype produces a black base color?

EE or Ee at the extension gene.

What genotype produces a red base color?

ee at the extension gene.