Which of the following is an example of recessive epistasis?
Option: 1
Coat color in mice
Option: 2
Height in humans
Option: 3
Flower color in snapdragons
Option: 4
Seed shape in peas
Answers (1)
Recessive epistasis is the term for when recessive alleles at one locus conceal the expression of both (dominant and recessive) alleles at a different locus.
The term "supplementary epistasis" is another name for this kind of gene interaction.
Pigmentation in mice, which is regulated by the two gene pairs A/a and C/c, is an example of recessive epistasis.
When gene A/a is recessive homozygous, dominant C provides black coloring.
Agouti is created when gene A is homozygous recessive or heterozygous with gene C/c.
Albino/white coats are created when the homozygous recessive version of the gene C/C hides the creation of any color.
Gene C/c is hence epistatic in a recessive homozygous state.
This happens because a mouse with a recessive c allele at this locus is unable to produce pigment and is albino regardless of the allele present at locus A.