Microsatellite repeat sequences

Microsatellite repeat sequences Dispersed or group repeat sequences of 2-5 bp repeated up to 50 times. May occur at 50-100 thousand locations in the genome. 

The instability of simple repeat sequences is called microsatellite instability (MSI), and it is used as a tool for the diagnosis of HNPCC. It is thought to be caused by... 

Microsatellites (simple sequence repeats, simple tandem repeats)—regions of DNA composed of short two, three, or four nucleotides repeated 2-50 times. 

Microsatellite repeat markers—Highly polymorphic DNA sequences of short repeats generally comprising <6... 

AGTAGTAGTAGTAGT... ), etc. Due to polymerase slip (a.k.a. polymerase chatter), during DNA replication there is a slight chance these repeat sequences may become altered copies of the repeat unit can be created or removed. Consequently, the exact number of repeat units may differ between unrelated individuals. Considering all the known microsatellite markers, no two individuals are identical. This is the basis for forensic DNA identification and for testing of familial relationships (e.g., paternity testing). 

Single Nucleotide Polymorphism Database (dbSNP) of Nucleotide Sequence Variation. URL http //www.ncbi.nlm. nih.gov/SNP/index.html. Uses SNP in the much looser sense of minor genetic variations and includes microsatellite repeats and small insertion/deletion polymorphisms. 

There are several major types of DNA sequence variation in the human genome. One type comprises repeated sequences with variations in the number of repeat units, such as short tandem repeat polymorphisms (STRPs, also known as microsatellites) in the form of mono-, di-, tri-, and tetra-nu-cleotide repeats, or more complex sequence repeats such as variable number tandem repeats (VNTRs) [2-4]. Repeat polymorphisms are relatively... 

Debrauwere, H., C. G. Gendrel, S. Lechat, and M. Dutreix. 1997. Differences and similarities between various tandem repeat sequences Minisatellites and microsatellites. Biochimie 79 577-86. 

A third type of polymorphism is due to tandem repeats of short sequences that can be detected by PCR-based analysis. These are known variously as microsatellites, short tandem repeats (STRs), STR polymorphisms (STRPs), or short sequence length polymorphisms (SSLPs). These repeat sequences usually consist of two, three, or four nucleotides and are plentiful in most organisms. All PCR-converted STR markers (those for which a pair of oligonucleotides flanking the polymorphic site suitable for PCR amplification of the locus has been designed) are considered to be STSs. The advent of PCR-based analysis quickly made microsatellites the markers of choice for mapping. 

Zarlenga, D.S., Aschenbrenner, R.A. and Lichtenfels, J.R. (1996) Variations in microsatellite sequences provide evidence for population differences and multiple ribosomal gene repeats within Trichinella pseudospiralis. Journal of Parasitology 82, 534-538. 

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