Chapter 10, Problem 32P

Summary Introduction

To analyze:

Based on the result of western blot given below:

1. Identify the protein change resulting in two bands observed in the western blot for organisms having ${\text{Dd}}_{\text{2}}$ genotype.

2. The absence of detectable protein for organisms with the ${\text{d}}_{\text{1}}{\text{d}}_{\text{1}}$ genotype.

3. The reason behind presence of just one detectable protein band for organisms having ${\text{d}}_{\text{1}}{\text{d}}_{\text{2}}$ and ${\text{d}}_{\text{2}}{\text{d}}_{\text{2}}$ genotypes.

4. Based on evaluation of western blot analysis, project the nature of the mutations generating ${\text{d}}_1$ and ${\text{d}}_2$. In other words, changes at the DNA level led to production of these mutations.

Introduction:

Genes encode the functional protein and enzymes; these protein and enzymes perform specific functions to express specific phenotypes. The experimental approach, western blotting, is used to observe the protein level expression pattern of a gene. An individual has two alleles for one gene whereas when multiple alleles for one gene are present in a population, the population is termed as polymorphic population. Dominant allele (D) encodes the functional enzyme but recessive allele (d) does not encode a functional protein. The band pattern for a heterozygous individual is observed in lane $2$. The dominant allele suppresses the effect of a recessive allele.

D

Another recessive allele (${\text{d}}_2$) encodes the protein that inhabits the expression of the dominant allele (D). The band pattern of recessive allele (${\text{d}}_2$) is observed in western blotting.