Difference Between Reversion and Suppression Mutation

The key difference between reversion and suppression mutation is that reversion mutation is a mutation that precisely restores the wild type DNA sequence back while the suppression mutation is a second mutation at a distinct site which suppresses the phenotypic effect of the first mutation.

A mutation is a change in a nucleotide sequence of DNA. Since the nucleotide sequence of a gene has crucial information to produce a protein, a single nucleotide change may result in a deleterious effect. Most mutations are deleterious, while some mutations may be beneficial in certain environments. Mutations arise as a mistake of DNA copying during the cell division or mainly due to chemicals, radiation, or environmental factors. Some mutations are inherited to the next generations while some are not transmitted. There are different types of mutations. Reversion mutation restores the wild type DNA sequence while suppression mutation suppresses the phenotype of another mutation which is known as the first mutation.

CONTENTS

1. Overview and Key Difference
2. What is Reversion Mutation
3. What is Suppression Mutation
4. Similarities Between Reversion and Suppression Mutation
5. Side by Side Comparison – Reversion vs Suppression Mutation in Tabular Form
6. Summary

What is a Reversion Mutation?

Reversion mutation is a kind of mutation that precisely restores the nucleotide sequence of the wild type. In other words, reversion mutation reverses the original wild type nucleotide sequence. Therefore, reversion mutation is able to restore the activity of the mutated gene back.

Reversion mutations generally appear to be due to the loss of a controlling element. Moreover, reversion can be by a suppression mutation. If the mutant gene and suppressor are closely linked, we can assume that the reversion is by a suppression mutation. Base substitution and frameshift mutations can also lead to reverse mutations. In base substitution, the mutant base pair should be replaced by the base pair in wild type. In frame-shift mutations, it requires deletion of one particular base from one particular site, or insertion of one particular base into one particular site.

What is a Suppression Mutation?

Suppression mutation is a second mutation which suppresses the phenotypic effect of the first mutation. Suppression mutation occurs at a site distinct from the first mutation. It can restore the original base sequence of the gene. There are two types of suppression mutations. They are intragenic suppression mutation and intergenic (extragenic) suppression mutations.

In intragenic suppression, suppressor lies within the same gene as the original mutation.  In intergenic suppression, suppressor lies somewhere else in the genome (mostly a different gene) compared to the site of the first mutation.

What are the Similarities Between Reversion and Suppression Mutation?

• Reversion and suppression mutations are two types of mutations.
• Some reversion mutations are suppression mutations.
• Both mutations restore the phenotype of the original gene.

What is the Difference Between Reversion and Suppression Mutation?

Reversion mutation is a mutation that restores the function of a mutant gene while suppression mutation is a  mutation that suppresses the phenotype of another mutation. So, this is the difference between reversion and suppression mutation. Reversion mutation reverses the original base sequence of DNA while suppression mutation suppresses the phenotypic effect of the first mutation or restores the original activity of the gene.

Below is a summary of the difference between reversion and suppression mutation in tabular form.

Summary – Reversion vs Suppression Mutation

Reversion mutation reverses the effect of the first mutation. It restores the original base sequence of the gene. As a result, the activity of the wild type gene resumes. Suppression mutation is a mutation which suppresses the phenotypic effect of the first gene. It also restores the gene activity in which the first mutation occurred. Suppression can be intragenic or intergenic. Reversion mutation can occur due to suppression mutation if the mutant gene and suppressor are closely linked. Thus, this is the summary of the difference between reversion and suppression mutation.

Reference:

1. Hodgkin, Jonathan. “Genetic Suppression.” WormBook: The Online Review of C. Elegans Biology [Internet]., U.S. National Library of Medicine, 27 Dec. 2005, Available here.
2. “Suppressor Mutation.” Wikipedia, Wikimedia Foundation, 12 Dec. 2020, Available here.

Image Courtesy:

1. “Point mutation” By PoojaN212 (CC BY-SA 4.0) via Commons Wikimedia
2. “Tevenphage”By Adenosine (original); en:User:Pbroks13 (redraw) – http://commons.wikimedia.org/wiki/Image:Tevenphage.png (CC BY-SA 2.5) via Commons Wikimedia