I’ve been discussing genetic markers a lot this last week. SNPs are often the type of genetic marker I refer upon in population genetic studies, but microsatellites are also a very informative genetic marker. Microsatellites are short repeating units of 1-4 base pairs in length and are polymorphic like SNPs. In a paper published in Genome Research, the polymorphic tendency of microsatellites in human–chimpanzee orthologs are investigated.
The paper, “The genome-wide determinants of human and chimpanzee microsatellite evolution,” first honed in on the number of repeats, the length, and motif size of the mircosatellites. These factors influence the probability of slippage that makes for the polymorphisms. The length and motif composition of each microsatellites was also scrutinized because mutagenesis nonuniformly increases with length and depending on the motif composition, secondary DNA structure create break points.
Their regression models, tests to figure out the influence of one variable from one or more other variables in microsatellite mutagenesis, explained for about 90% of variation in microsatellite mutability. Not bad!