Program

     Photosynthetic dinoflagellates in the genus Symbiodinium (collectively called zooxanthellae) are typical coral endosymbionts consisting of at least nine phylogenetically discrete clades (A–I). The study of Symbiodinium diversity offers critical insight into the flexibility and specificity of coral-algal symbiosis. In order to better understand the community structure and functional diversity of coral reef ecosystem, we collected wild corals from geographically contrasting regions along southeast coast of China (including Dongshan Island, Fujian; Sanmen Island, Guangdong; Hainan Island, Hainan; Weizhou Island, Guangxi; Green Island, Taiwan), as well as corals from aquarium cultivation. Using the 454 GS FLX next-generation sequencing (NGS) technology, we sequenced the PCR-amplified internal transcribed spacers (ITS 1 and 2) and 5.8S regions of Symbiodinium species extracted from the corals to investigate the patterns of Symbiodinium community structure. Our NGS deep sequencing results reveal that the majority of coral hosts appear to harbor a high level of symbiont specific to clade C, but some colonies can harbor more than one clade concurrently with background A, D, E, F or G, suggesting symbiont communities can remain stable among different hosts across geographic distances. But additional work in other geographic regions is necessary to test this idea. This study provides a means of evaluating the coral-zooxanthellae diversity and plasticity with improved sensitivity and resolution, expanding our understanding of the genetic basis underlying the coral responses to environmental changes.

Keywords: Coral, next generation sequencing, Symbiodinium, southeast coast of China