Abstract

Symbionts are adapted to work with corals Many corals have formed mutualistic associations with dinoflagellate symbionts, which are thought to provide nutrients and other benefits. To examine the underlying genetics of this association, S. Lin et al. sequenced the genome of the endosymbiont dinoflagellate Symbiodinium kawagutii. The genome includes gene number expansions and encodes microRNAs that show complementarity to genes within the coral genome. Such microRNAs may be involved in regulating coral genes. Furthermore, coral and S. kawagutii appear to share homologs of genes encoding specific nutrient transporters. The findings shed light on how symbiosis is established and maintained between dinoflagellates and corals. Science , this issue p. 691