mikrosatellites

Mikrosatellites, also known as Short Tandem Repeats (STRs) or Simple Sequence Repeats (SSRs), are highly repetitive sequences of DNA. They consist of a short core motif, typically 1 to 6 base pairs long, that is repeated multiple times in a tandem array. For example, a mikrosatellite might have the sequence (GATA)n, where 'n' represents the number of times the GATA motif is repeated. The number of repeats can vary significantly between individuals, making mikrosatellites valuable genetic markers.

These repetitive regions are found throughout the genomes of most eukaryotic organisms, including humans. They are often located in non-coding regions of DNA, though they can also occur within genes. The variability in repeat numbers arises from errors during DNA replication, such as DNA polymerase slippage, and subsequent repair mechanisms. This process leads to the expansion or contraction of the repeat array.

The high degree of polymorphism (variation) at mikrosatellite loci makes them extremely useful in various fields of molecular biology and genetics. They are widely employed in DNA fingerprinting for forensic investigations, paternity testing, and population genetics studies. In forensics, a panel of highly variable mikrosatellite markers can uniquely identify an individual from a DNA sample. In population genetics, mikrosatellite data can reveal relationships between populations, track gene flow, and assess genetic diversity. Their small size and relative ease of analysis through PCR (polymerase chain reaction) and gel electrophoresis have contributed to their widespread adoption.