What is the Difference Between Homologous Recombination and Non-homologous Recombination?

Homologous recombination and non-homologous recombination are two distinct types of genetic recombination that differ in their mechanisms and outcomes. Here are the main differences between them:

Homologous Recombination (HR):

• Involves the exchange of genetic information between two similar or identical molecules of DNA.
• Occurs during the S, G2, and M phases of the cell cycle.
• Results in accurate and error-free DNA repair.
• Requires sequence homology between the donor and recipient DNA molecules.

Non-homologous Recombination (NHR):

• Causes genetic additions of new material and is also called lateral gene transfer (LGT).
• Involves the rejoining of broken DNA ends with little or no homology, generating deletions or insertions.
• Occurs in both the G1 and G2/M phases of the cell cycle.
• Is intrinsically mutagenic and less accurate than homologous recombination.

In summary, homologous recombination is a more accurate and precise mechanism of DNA repair that requires sequence homology between donor and recipient DNA molecules, while non-homologous recombination is less accurate and can introduce genetic additions or alterations. The choice between these two mechanisms depends on various factors, including the need for accurate DNA repair and the availability of homologous sequences.

Comparative Table: Homologous Recombination vs Non-homologous Recombination

Here is a table comparing homologous recombination and non-homologous recombination:

Homologous recombination ensures accurate repair by using the un-damaged sister chromatid or homologous chromosome as a template, while non-homologous recombination directly ligates break ends without the need for homology. Homologous recombination is conserved across all domains and in DNA and RNA viruses, whereas non-homologous recombination is not.