SNP(Single Nucleotide Polymmorphism) Marker

SNP(Single Nucleotide Polymmorphism) are the last generation molecular marker and they occur in high frequencies in both plants and animal genome. SNP describes the variation among different individuals of a species foe a single base pair of the corresponding site of their genome.

A SNP locus can have four alleles each allele represented by one of the four DNA nucleotide. SNPs are extremely abundant ( about 1 SNP for every 100-300 bp of plant genome). SNPs has low mutuation rates and they are easy to detect. they are present more in non-coding region as compaired to coding region.

Although SNPs are less polymorphic than SSR markers because of their biallelic nature, they easily compensate this drawback by being abundant, ubiquitous and amenable to high and ultrahigh throughput automation.

What is the difference between mutuation and SNPs?

Mutuation is defined as the variation in the DNA sequence of an organism leading to deletion, insetion, duplication or subsitition of the one or more nucleotides. therefore SNPs are a type of mutation, but all mutation are not SNPs. Single nucleotide mutation is a SNP when it occcurs in more than 1 % of he population or subpopulation.

SNP= Frequency >1% in population

Mutation= Frequency <1% in population

For further information about SNPs:

• Mammadov, J., Aggarwal, R., Buyyarapu, R., & Kumpatla, S. (2012). SNP Markers and Their Impact on Plant Breeding. International Journal of Plant Genomics, 2012, 1–11. doi:10.1155/2012/728398 
• Zhang, W., Mirlohi, S., Li, X., & He, Y. (2018). Identification of Functional Single-Nucleotide Polymorphisms Affecting Leaf Hair Number inBrassica rapa. Plant Physiology, 177(2), 490–503. doi:10.1104/pp.18.00025