Difficulties in obtaining microsatellites from acroporid corals

Microsatellites are currently the molecular marker of choice in population genetics but their recovery from acroporid corals has been largely unsuccessful. We report the results of six attempts to develop microsatellites, representing five distinct melhodological approaches, undertaken within three independent labs. Conventional screening of 50,000 clones from twoAcroporafonnosa genomic libraries produced five single-copy, polymorphic microsatellites, of which only one may be useful for population genetics. Other projects tried to improve on this low recovery using different microsatellite environment techniques, such as affinity chromatography, strand extension using biotin-labelled probes, PCR with synthetic microsatellites and isolation from RAPD fragments. However, all of them failed to yield any additional loci. Apart from technical problems involved in microsatellite recovery, the small genome of acroporid corals and the correlation between genome size and microsatellite abundance suggests that biological constraints may limit the number of microsatellite loci in these corals