Question

In rabbits, coat color is controlled by a single gene with multiple alleles. A wild-type rabbit is crossed with a chinchilla rabbit and some of the offspring are light chinchilla. What is the genotype of the wild-type parent?

Answer 1

Answer:

The wild type =  $C^{+}c$

Explanation:

This concept can be understood from what is termed as Multiple Allele.

         Multiple allele can be defined as a series of three or more alternative allelic forms of a gene, in which only two of which can exist in any normal diploid individual or organism. Now, in a population, multiple allele can exist. If many allele is present for the same gene, the analysis of such is to denote the most common phenotype or genotype among wild animals as the wild type (“+”) and the rest of the phenotype or genotype are regarded as variants which implies that they deviate from the wild type which may be dominant or recessive of the wild type allele. Therefore, wild type is dominant over all other variants.

From our question , multiple alleles that occur coat color in rabbits is an integral example.

Let c represent the coat color, As such Four alleles can be observed in the c gene.

The wild type   $C^{+}C^+$

The chinchilla $c^{ch}c^{ch}$

The Himalayan $c^hc^h$

The albino(white) $cc$

In the case of multiple allele, dominance hierarchies can occur and as such:

The wild-type allele is dominant over all the others,

Chinchilla is incompletely dominant over Himalayan and albino(white), and

Himalayan is dominant over albino(white).

Now; If  A wild-type rabbit is crossed with a chinchilla rabbit and some of the offspring are light chinchilla.

The trait of the wild type rabbit will be $C^+c$ since wild-type is dominant over albino(white)

Also, the chinchilla will be $c^{ch}c$.

if both traits crossed, we have;

         $C^+$          $c$

$c^{ch}$      $C^+c^{ch}$     $cc^{ch}$

$c$         $C^+c$        $cc$

From the above punnet square, it is observed that the some of the offspring are light chinchilla in $cc^{ch}$ traits because Chinchilla is incompletely dominant over albino(white).