What is the Difference Between AFLP and RFLP

The main difference between AFLP and RFLP is that AFLP involves restriction digestion and selective amplification whereas RFLP involves digestion with restriction enzymes and detection with probes.

AFLP and RFLP are two PCR techniques that exploit variations in homologous DNA sequences. Generally, both detect polymorphism.

Key Areas Covered

1. What is AFLP
     – Definition, Technique, Importance
2. What is RFLP
     – Definition, Technique, Importance
3. Similarities Between AFLP and RFLP
     – Outline of Common Features
4. Difference Between AFLP and RFLP
     – Comparison of Key Differences

Key Terms

AFLP, RFLP

What is AFLP

AFLP or amplified fragment length polymorphism is the selective amplification of the digested DNA fragments to generate unique fingerprints for genomes. It was invented by KeyGene in the early 1990s. AFLP generally uses the digestion of genomic DNA in small pieces by restriction enzymes. Then, adaptors are ligated to the sticky ends of the restriction fragments. After that, these restriction fragments undergo selective amplification with the use of primers that are complementary to adaptor sequences.

Figure 1: RFLP Genotyping

Furthermore, gel electrophoresis involves the separation and visualization of amplified restriction fragments. The main importance of AFLP is that it helps to detect various polymorphisms in different regions of the genome. In addition, AFLP is a highly sensitive technique that is reproducible. More importantly, AFLP is used in DNA fingerprinting.  

What is RFLP

RFLP or restriction fragment length polymorphism is the technique that identifies the variations in the polymorphic regions of the genome. It was invented by Alec Jeffreys in 1984s. Generally, most restriction markers are codominant and they occur in two alleles that are heterozygous. They are also highly-locus-specific.

Figure 2: DNA Fingerprinting

Moreover, RFLP involves the digestion of the genome with restriction enzymes. Restriction fragments hybridize with one or two probes in order to detect the polymorphism pattern. Furthermore, this detects the genotypes of the specific locus. In general, RFLP is important in genome mapping and in variation analysis including genotyping, paternity testing, and forensics.

Similarities Between AFLP and RFLP

• AFLP and RFLP are two techniques that exploit variations in homologous chromosomes.
• Generally, both involve the digestion of total cellular DNA with one or more restriction enzymes.
• Both AFLP and RFLP are important in the detection of polymorphism.

Difference Between AFLP and RFLP

Definition

AFLP or amplification fragment length polymorphism refers to a PCR-based technique that uses selective amplification of a subset of digested DNA fragments to generate and compare unique fingerprints for genomes of interest. RFLP or restriction fragment length polymorphism, on the other hand, refers to a technique that exploits variations in homologous DNA sequences in order to distinguish individuals, populations, or species or to pinpoint the locations of genes within a sequence.

Invention

AFLP was invented by KeyGene in the early 1990s while RFLP was invented by Alec Jeffreys in 1984s.

Detection

In general, AFLP detects polymorphism by selective amplification while RFLP detects polymorphism with probes.

Importance

Moreover, AFLP is important in DNA fingerprinting while RFLP is important in genome mapping and localization of genetic disorders.

Conclusion

In brief, AFLP and RFLP are two PCR techniques that detect polymorphism in the genome. In general, AFLP involves restriction digestion followed by selective amplification. RFLP, on the other hand, involves restriction digestion followed by detection with probes. Therefore, the main difference between AFLP and RFLP is the method of detection.    

References:

1. “Restriction Fragment Length Polymorphism (RFLP).” National Center for Biotechnology Information, U.S. National Library of Medicine, 
2. “Restriction Fragment Length Polymorphism (RFLP).” National Center for Biotechnology Information, U.S. National Library of Medicine, 

Image Courtesy:

1. “Gel Electrophoresis in DNA Fingerprinting” By Jennifer0328 – Own work (CC BY-NC-SA 2.0) via Commons Wikimedia
2. “RFLP genotyping” By OgreBot – Own Work (Public Domain) via Commons Wikimedia