Genome evolution: Are microsatellites really simple sequences?

In 1989, the world started to look much brighter for genome mappers and behavioral ecologists: the polymerase chain reaction (PCR) and a type of sequence known as a microsatellite were brought together in the development of potentially powerful new methods for mapping genomes. Microsatellites seemed to have almost all the features required by those seeking a simple molecular way of tracking regions of the genome — they are abundant, codominant, distributed over the euchromatic part of the genome and highly polymorphic. At that time, there was no need to know more about the nature of the mutational processes underlying microsatellite variability; it was sufficient to know that microsatellites are stable over a couple of generations. In the subsequent years, microsatellites have significantly influenced both genome mapping and behavioral ecology. The impact of microsatellite analysis on contempory biology is vividly illustrated by the steadily growing number of genes that have been mapped, cloned and characterized by genetic maps based on microsatellites.