How do microsatellites form?
Several studies have found evidence that slippage is the cause of microsatellite mutations. Typically, slippage in each microsatellite occurs about once per 1,000 generations. Thus, slippage changes in repetitive DNA are three orders of magnitude more common than point mutations in other parts of the genome.
How do microsatellites evolve?
One model of microsatellite evolution posits that stationary length distributions arise from a balance between length mutations, which tend to promote repeat growth, and point mutations, which tend to break long repeat arrays into smaller units.
What are microsatellites?
Microsatellite, as related to genomics, refers to a short segment of DNA, usually one to six or more base pairs in length, that is repeated multiple times in succession at a particular genomic location. These DNA sequences are typically non-coding.
How do microsatellites tend to mutate?
It is accepted that the most common mutational mechanism affecting microsatellites is replication slippage, a process involving a gain or contraction of one or more repeat units [5,6]. Other microsatellite mutations might be caused by unequal crossing over, nucleotide substitutions, or duplication events [7].
What are two features of microsatellites?
Particular characteristics of microsatellites, such as their presence in the genomes of all living organisms, high level of allelic variation, co-dominant mode of inheritance and potential for automated analysis make them an excellent tool for a number of approaches like genotyping, mapping and positional cloning of …
What are microsatellites and how do they differ from SNPs?
Microsatellite polymorphisms can arise through replication slippage, unequal crossing over, or mutations extending or interrupting a series of repeats, whereas SNPs arise via point mutations. As a result, new microsatellite variations arise more frequently than new SNP variations.
How are microsatellites genotyped?
Genotyping is the process to identify the genotype of each microsatellite. The workflow of microsatellite genotyping generally involves specific primer design, amplification of microsatellites, and Polymorphism testing.
How are microsatellites used as molecular markers?
They serve a role in biomedical diagnosis as markers for certain disease conditions. That is, certain microsatellite alleles are associated (through genetic linkage) with certain mutations in coding regions of the DNA that can cause a variety of medical disorders.
How do microsatellite markers work?
Microsatellite marker analysis involves PCR amplification of the microsatellite loci using fluorescently labeled primers that flank the repeated sequence. The labeled PCR products are then analyzed by CE to separate the amplicons by size.
Why are microsatellites used as markers?
Mutation process: Microsatellites are useful genetic markers because they tend to be highly polymorphic. It is not uncommon to have human microsatellites with 20 or more alleles and heterozygosities (Hexp = gene diversity, D) of > 0.85.
How are microsatellites analyzed?
How are microsatellites used in DNA profiling?
Microsatellites or STRs are repetitive co-dominant sequences of 2–6 bp of DNA that are present throughout the entire genome. They are often used for identification or fingerprinting of DNA. Microsatellites are amplified by PCR using fluorescently labeled primers and the amplicons are separated using CE.