Chapter 10, Problem 21P

Summary Introduction

To analyze:

1. Identify the genotypes of individuals depicted in lanes $1$, $2$ and $3$ in the gel image given below.

2. In lanes $4$, $5$, and $6$, draw the band patterns expected for individuals with, genotypes $\text{R1R3}$, $\text{R3R4}$, and $\text{R1R1}$ respectively.

In the given example, the DNA fragments from four alleles of a marker gene are as follows:

R $1$ is $4$ kb

R $2$ is $13$ kb

R $3$ is $10$ kb

R $4$ is $7$ kb

Introduction:

Electrophoresis is an experimental approach for the separation of protein, DNA, and mRNA. The

separation can be done on the basis of molecular weight, shape and charge of protein, DNA, and

mRNA under the electric field. There are two different types of electrophoresis, i.e., Polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS). The movement of a molecule is dependent on the pore size of gel. The gel electrophoresis is done after restriction digestion.

DNA preparations from different individuals normally show different patterns of size distribution of restriction fragments that hybridize with a particular probe. These modifications are named restriction fragment length polymorphisms (RFLPs).

The RFLP analysis technique involves separation of DNA sample into parts by one or more restriction enzymes. According to the size of resulting parts, they are separated by gel electrophoresis.