Page "Microsatellite" Paragraph 12

When using microsatellites to compare species, homologous loci may be easily amplified in related species, but the number of loci that amplify successfully during PCR may decrease with increased genetic distance between the species in question.

Mutation in microsatellite alleles is biased in the sense that larger alleles contain more bases, and are therefore likely to be mistranslated in DNA replication.

Smaller alleles also tend to increase in size, whereas larger alleles tend to decrease in size, as they may be subject to an upper size limit ; this constraint has been determined but possible values have not yet been specified.

If there is a large size difference between individual alleles, then there may be increased instability during recombination at meiosis.

In tumour cells, where controls on replication may be damaged, microsatellites may be gained or lost at an especially high frequency during each round of mitosis.

Hence a tumour cell line might show a different genetic fingerprint from that of the host tissue.