Exploring the Genetics of Mouse Coat Color

What determines the recessive gene in these mice?

A. Dark eyes

B. White fur

C. Black fur

D. Red eyes

Answer:

The recessive gene in these mice is white fur, due to the presence of a homozygous recessive cc genotype, which is epistatic and leads to albinism regardless of other color-related alleles.

The recessive gene in these mice is white fur. This can be determined by understanding how genetic dominance and epistasis work in coat color inheritance in mice. According to the information provided, the mottled agouti coat color (A) is dominant over solid coloration such as black or gray. However, a separate gene locus (C) is responsible for pigment production.

When the recessive c allele is present in a homozygous state (cc), it results in an albino mouse, which has white fur regardless of the agouti gene. This means that the c allele does not produce pigment, leading to white fur being the recessive trait. As a result, the C gene locus is epistatic to the A gene locus. Therefore, even if the alleles for dark eyes, black fur, or red eyes are present, they will not determine the mouse's coat color if the cc genotype is also present, leading to albino, or white fur.

Understanding the intricate genetics behind mouse coat color can be fascinating and sheds light on how traits are inherited and expressed in different organisms. By unraveling these genetic mysteries, researchers and breeders can better predict and manipulate traits to achieve desired outcomes. The study of genetics continues to amaze us with its complexity and beauty, showcasing the wonders of the natural world.