Microsatellite DNA marker in aquatic organisms

For the last 50 years, attempts have been made to discriminate among populations by using molecular markers. Although some techniques have proved successful in certain circumstances, the consistent trend to newer markers among fishery geneticists highlights the general lack of resolving power observed with older technologies. The last three decade has seen the increasing use of satellite DNA in investigations of genetic variability and divergence. The large interest in microsatellite loci is largely due to the very high levels of variability that have been observed and the ability to investigate this variation using PCR technology. The isolation and application of microsatellites to research fields as diverse as population genetics, parentage analyses and genome mapping are reviewed. Statistical considerations (e.g. appropriate sample sizes, number of loci and the mutation model assumptions on which the estimate is based) have not been considered in detail yet and the problems are often exacerbated in aquatic species, as some species show very large numbers of alleles at microsatellite loci.