What is the Difference Between Intragenic and Extragenic Suppressor Mutation?

🆚 Go to Comparative Table 🆚

The difference between intragenic and extragenic suppressor mutations lies in the location of the suppressor mutation relative to the original mutation.

Intragenic Suppressor Mutation:

  • Occurs within the same gene as the original mutation.
  • Can restore the original function of the mutated gene by various mechanisms, such as same-site replacement, compensatory mutation, alteration in splicing, or reversion of dominant mutations by cis-knockout.
  • Useful for identifying regions, specific amino acids, or interactions necessary for functional activity and stability.

Extragenic Suppressor Mutation:

  • Occurs in a different gene than the original mutation, also known as intergenic suppression.
  • Can alleviate the effects of the original mutation by a variety of informational mechanisms, such as alterations in splicing, translation, or nonsense-mediated decay.
  • Useful for identifying and studying interactions between molecules, such as proteins, and can help investigate relationships between genes.

Both intragenic and extragenic suppressor mutations can restore the original phenotype of the mutated gene, but they occur in different locations within the genome and provide different types of information about the initial gene studied.

Comparative Table: Intragenic vs Extragenic Suppressor Mutation

Intragenic and extragenic suppressor mutations are both types of suppression mutations that correct the original function of a mutated gene. However, they differ in the location of the second mutation. Here is a table comparing the differences between intragenic and extragenic suppressor mutations:

Feature Intragenic Suppressor Mutation Extragenic Suppressor Mutation
Location Occurs within the same gene as the original mutation Occurs in a different gene
Mechanisms Same-site replacement, compensatory mutation, alteration in splicing, and reversion of dominant mutations by cis-elements Relieves the effects of a mutation in one gene by a mutation elsewhere within the genome
Examples dnaDΔ154-155, dnaDA138G, dnaDT148M, dnaDA166S, and dnaDW188L dnaBS371P, dnaBH65Y, dnaBS151P, dnaBA164V, dnaBE288K

Both intragenic and extragenic suppressor mutations suppress the phenotypic effect of the first mutation, but intragenic mutations occur within the same gene, while extragenic mutations occur in a different gene.