What is the Difference Between Homologous Recombination and Non-homologous Recombination?
🆚 Go to Comparative Table 🆚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:
Feature | Homologous Recombination | Non-homologous Recombination |
---|---|---|
Definition | A type of genetic recombination that takes place during meiosis and requires DNA homology. | A pathway that repairs DNA double-strand breaks, directly ligating break ends without the need for homology. |
Mechanism | Occurs through strand invasion, producing recombinant chromosomes. | Occurs through end processing to seal double-stranded breaks. |
Accuracy | Ensures accurate repair by using the un-damaged sister chromatid or homologous chromosome as a template. | Intrinsically mutagenic, as it generates deletions or insertions. |
Role in DNA Damage Repair | Repairs DNA damages caused by ionizing radiation or damaging chemicals. | Repairs DNA double-strand breaks. |
Efficiency | Less efficient than non-homologous recombination in unsynchronized proliferating cell populations. | More efficient than homologous recombination in unsynchronized proliferating cell populations. |
Conservation | Conservative, occurring in all domains and in DNA and RNA viruses. | Not conserved across all organisms. |
Subpathways | Includes single-strand annealing, gene conversion, and break-induced replication. | DNA end-joining, which is the main pathway. |
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.
- Homologous Recombination vs Site-Specific Recombination
- Recombinant vs Nonrecombinant
- Recombination vs Crossing Over
- Complementation vs Recombination
- Nonhomologous End Joining vs Homologous Direct Repeat
- Linkage vs Recombination
- Mutation vs Recombination
- Interchromosomal vs Intrachromosomal Recombination
- Homologous vs Homeologous Chromosomes
- Homologous Chromosomes vs Sister Chromatids
- Homoplasy vs Homology
- Homologous vs Analogous
- Transformants vs Recombinants
- Crossover Frequency vs Recombination Frequency
- Somatic Hypermutation vs V(D)J Recombination
- Genetic Engineering vs Recombinant DNA Technology
- Homozygous vs Heterozygous
- Hybridization vs Cloning
- Parental Type vs Recombinant Type Chromosomes