Key Difference – Genotyping vs Sequencing
Genotyping and sequencing are two techniques performed to obtain information about the nucleic acids, mainly DNA of an organism. The key difference between genotyping and sequencing is that genotyping is the process of determining which genetic variant the individual possesses using markers while sequencing is the determination of the correct order of the nucleotide sequence within the given fragment of DNA.
CONTENTS
1. Overview and Key Difference
2. What is Genotyping
3. What is Sequencing
4. Side by Side Comparison – Genotyping vs Sequencing
5. Summary
What is Genotyping?
Genotyping is the determination of the genetic makeup of an individual using a sequence of DNA and markers and comparison and identification of its inheritance. Genotyping is important in evolutionary biology, population biology, taxonomy, ecology, and genetics of the organisms. It can be performed by different techniques including DNA sequencing, polymerase chain reaction, restriction fragment length polymorphism (RFLP), random amplified polymorphic detection, amplified fragment length polymorphism (AFLP), DNA microarrays, etc.
Genotyping involves sequencing of particular small fragments of DNA sequences and finding of relatedness of the genetic composition with other individuals using genetic markers. It determines the single nucleotide polymorphisms (SNPs) among the individuals or the specific alleles. Genotyping is applicable to a wide range of organisms including humans. It is also applicable to microorganisms such as viruses, fungi etc. and can be used to determine their genetic variants with the reference profiles. In molecular epidemiology and forensic microbiology, controlling of pathogens, especially microorganisms, is done by the information obtained from genotyping. Genotyping is very important in pedigree analysis. Humans are genotyped to confirm motherhood and fatherhood. Genotype will reveal the dominant and recessive alleles of genes which decide specific traits.
Figure_1: RFLP Genotyping
What is Sequencing?
Sequencing is the process of determining the correct order of the nucleotide in a given fragment of DNA or RNA. Virtually all information required for the growth and development of an organism is encoded in its genome. The availability of techniques to produce and separate a few hundred nucleotides long nucleic acids fragments led to the development of procedures of determining the exact nucleotide sequence of a given fragment of DNA or RNA. Different types of sequencing methods are available today. These sequencing methods, together with the technologies for construction of genome libraries representing the entire genome of an organism, facilitate the sequencing of the entire genome of that organism, making in-depth analysis of gene structures, gene functions, gene locations, gene expressions, gene mapping, gene regulatory regions etc.
The total genomes of many viruses, several bacteria, archaebacteria, yeast and several some other organisms have been sequenced and mapped. Human genome project has made it possible to sequence and map the entire human genome and publish its first draft in 2003. It is a major milestone in the advancement of biology. Human genome sequences are now used in the medical sector to identify genetic causes for rare diseases, screen disease risk in newborns, identify genetic details of different cancers, develop new therapeutics, and develop new diagnostic tools, etc.
In the plant world, rice genome and Arabidopsis genomes have been sequenced. Knowledge of these sequences will undoubtedly revolutionize our understanding of how cells and organisms function.
Figure_2: An autoradiograph of sanger sequencing
What is the difference between Genotyping and Sequencing?
Genotyping vs Sequencing |
|
| Genotyping is the process of determining the genetic composition of an individual and checking the group or the taxonomy of that organism. | Sequencing is the process of determining the precise order of nucleotides of a given DNA or RNA fragment. |
| Techniques | |
| RFLP, Gene sequencing, PCR, DNA microarrays, AFLP etc. | Sanger sequencing, Gilbert sequencing, Pyrosequencing, Next Generation Sequencing, Shotgun sequencing etc. |
| Major Concerns | |
| This is more concerned about whether the genotype differences are giving the actual phenotype differences. | This is more concerned about the order of the nucleotides and its differences and changes with other organisms. |
Summary – Genotyping vs Sequencing
Genotyping and sequencing are useful for studying the genetic information of organisms. Genotyping is the process of determining genotype variations among individuals and finding their categories. Sequencing is the process of determining the correct order of the nucleotides in the interested fragment or the region of DNA. Both techniques provide important information about the genes and genomes.
Reference:
1. “Genotyping methods.” Methods in molecular biology (Clifton, N.J.). U.S. National Library of Medicine, n.d. Web. 20 Feb. 2017.
2. Akey, J. M., D. Sosnoski, E. Parra, S. Dios, K. Heister, B. Su, C. Bonilla, L. Jin, and M. D. Shriver. “Melting Curve Analysis of SNPs (McSNP ): A Gel-Free and Inexpensive Approach for SNP Genotyping.” BioTechniques 30.2 (2001): 358-67. Web.
Image Courtesy:
1. “RFLP genotyping”By (unknown) – National Institutes of Health (Public Domain) via Commons Wikimedia
2. “Radioactive Fluorescent” By Abizar at English Wikipedia (CC BY-SA 3.0) via Commons Wikimedia