What is the Difference Between Intragenic and Intergenic Suppressor Mutation

The main difference between intragenic and intergenic suppressor mutation is that intragenic suppressor mutation occurs in the same gene as the original mutation whereas intergenic suppressor mutation occurs somewhere else in the genome. Furthermore, intragenic suppressor mutation ameliorates the primary mutation in the same gene while intergenic suppressor mutation ameliorates a primary mutation that occurs somewhere else in the genome.

Intragenic and intergenic suppressor mutation are two types of secondary mutations, which relieve the effect of a primary mutation in the genome by reversing the effect of the primary mutation on the gene product.

Key Areas Covered

1. What is an Intragenic Suppressor Mutation
     – Definition, Occurrence, Effect
2. What is an Intergenic Suppressor Mutation
     – Definition, Occurrence, Effect
3. What are the Similarities Between Intragenic and Intergenic Suppressor Mutation
     – Outline of Common Features
4. What is the Difference Between Intragenic and Intergenic Suppressor Mutation
     – Comparison of Key Differences

Key Terms

Intergenic Suppressor Mutation, Intragenic Suppressor Mutation, primary Mutation, Suppressor Mutation

What is an Intragenic Suppressor Mutation

Intragenic suppressor mutation is a second mutation that occurs in a gene, relieving the effect of a primary mutation of the same gene. Two types of intragenic suppressor mutations can occur based on the position of the second mutation. In order to restore the primary mutation, which is a point mutation, the mutant codon can be altered to another codon, which results in a less detrimental amino acid at the mutant position.

Figure 1: Types of Primary Mutations

Or else, the second mutation may occur in a distinct codon to the codon with the primary mutation. And, this alters the wild type amino acid in another position as well. But, it can restore the function of the protein closer to the wild type activity. However, the main importance of intragenic suppressor mutations is that they provide information about the structure of the functional relationship of a protein.

What is Intergenic Suppressor Mutation

Intergenic suppressor mutation is another type of a second mutation that occurs in a gene. It has the ability to restore the function of a protein produced by a second gene affected by a primary mutation. In other words, the second mutation does not occur in the gene with the primary mutation. Further, this type of second mutations is also known as extragenic suppressor mutation.

Besides, the main importance of an intergenic suppressor interaction is that it helps to determine the protein-protein interactions between the primary mutant and the protein with the second mutation. To date, several proteins with such interactions have been identified in biochemical, signal transduction, and gene expression pathways.

Similarities Between Intragenic and Intergenic Suppressor Mutation

• Intragenic and intergenic suppressor mutation are two types of second mutations.
• They are responsible for relieving the effect of a primary mutation on a particular gene.
• Moreover, they are classified based on the location of the affected gene in the genome.
• Also, both types of mutations do not bring the true wild type sequence of the gene.
• But, they restore the original phenotype.

Difference Between Intragenic and Intergenic Suppressor Mutation

Definition

Intragenic suppressor mutation refers to a second mutation within the same gene, which restores the function of the mutant gene product while intergenic suppressor mutation refers to a second mutation which relieves the effects of a mutation in one gene by a mutation somewhere else within the genome. Thus, this explains the main difference between intragenic and intergenic suppressor mutation.

Occurrence

Furthermore, intragenic suppressor mutation occurs in the same gene where the primary mutation exists while intergenic suppressor mutation occurs somewhere else in the genome other than the gene with the primary mutation. Hence, this is also an important difference between intragenic and intergenic suppressor mutation.

Effect

The effect is another difference between intragenic and intergenic suppressor mutation. Intragenic suppressor mutation relieves the effect of a primary mutation within the same gene while intergenic suppressor mutation relieves the effect of a primary mutation somewhere else in the genome.

Linkage to the Primary Mutation

Moreover, intragenic suppressor mutation is tightly-linked to the primary mutation while the intergenic suppressor mutation is not tightly-linked to the primary mutation.

Importance

Additionally, intragenic suppressor mutation provides information about the structure-function relationship of proteins while intergenic suppressor mutation provides information about functionally-related proteins to the primary mutant. Thus, this is one other difference between intragenic and intergenic suppressor mutation.

Conclusion

Intragenic suppressor mutation is a type of a second mutation which relieves the effect of a primary mutation that occurs in the same gene. Therefore, this type of mutations helps to determine the structure-function relationship of a protein. Whereas, intergenic suppressor mutation is a type of a second mutation that occurs in a gene which relieves the effect of a primary mutation of a gene other than the first gene. Therefore, intergenic suppressor mutations help to identify the functionally-related genes to the primary mutant. However, the main difference between intragenic and intergenic suppressor mutation is the occurrence and effect.

References:

1. Hodgkin J. Genetic suppression. 2005 Dec 27. In: WormBook: The Online Review of C. elegans Biology [Internet]. Pasadena (CA): WormBook; 2005-2018. Available Here. 

 Image Courtesy:

1. 1. “Point mutations-en” By Jonsta247 – Own work (CC BY-SA 4.0) via Commons Wikimedia