Question

In a rodent species from an island in the south Atlantic there are three different coat colors found in the population. Studies show that two genes (each with two alleles) determine the coat color in this species, and a dihybrid cross produces offspring with the coat colors in a 9:3:4 ratio. This is an example of?

Answer 1

Answer:

Epistatic gene interaction

Explanation:

A dihybrid cross is a mating or breeding experiment involving two organisms that are identically hybrid of two traits/genes. According to Mendel's law of independent assortment of genes, a dihybrid cross should yield progenies with 9:3:3:1 phenotype ratio. However, this is not always the case.

Sometimes in nature, a single gene can influence the emergence of two or more traits or phenotype and cause a shift away from the normal 9:3:3:1 phenotypic outcome in a dihybrid cross. This is known as pleiotropy.

Also, two or more genes can influence the appearance of a single trait or phenotype.  Allelic or non-allelic genes can interact in a number of ways to influence a trait and cause a shift away from independent assortment. This is referred to as epistasis or epistatic gene interaction.

In the species of rodent in question, it has already been reported that two genes determine the coat color and a dihybrid cross produced a phenotypic ratio that is different from 9:3:3:1. This is definitely an epistasis or epistatic gene interaction.