Cross species amplification of microsatellite loci: a valuable tool for genetic studies in plants

In recent times microsatellite analysis has become a favourite tool for a multitude of genetic related projects. However, one of the major drawbacks of this technology is that characterisation of useful loci relies on DNA sequence knowledge. As a result, the amount of resources required does not justify the development of these markers for all species. A potential alternative to taxon specific characterisation, is cross species amplification of microsatellite loci. Initially thought to be less successful in plants than in animals, recent research is increasingly showing otherwise. In this study, we have investigated the transferrability of microsatellite loci in angiosperms, both dicots (Myrtaceae) and monocots (Poaceae), and gymnosperms (Pinus). Thirty five primer pairs developed for tea tree (Melaleuca alternifolia - Myrtaceae), were tested on seven other Myrtaceae including other economically important species such as eucalypts. Success was over 80% within members of the same genus and over 20% for more distant species. Similar studies have been carried out with microsatellites developed for Saccharum spp. and Pinus spp. showing reasonable amounts of cross-transferability. The results suggest that cross-transferability of microsatellites can be a viable alternative to specific characterisation, especially for studies requiring a limited number of hypervariable loci such as population genetics studies.