Marine invertebrates such as soft corals are important sources of secondary metabolites with promising biomedical applications and commercial value. RNA isolation in conjunction with reverse-transcriptase polymerase chain reaction (RT-PCR) are valuable tools utilized to study the molecular elements involved in secondary metabolite production and functional genomics. Two total RNA extraction protocols were compared using fresh tissue and flash frozen preparations from the coral Pseudopterogorgia elisabethae and from its symbiont Symbiodinium sp. isolated using RNeasy minicolumns (Qiagen ® ) and Trizol reagent (Invitrogen ® ). In general, higher yields were obtained by using Trizol reagent when compared to RNeasy. No significant differences were observed in RNA yield when live or flash frozen tissue was used. However, flash frozen holobiont tissue isolated by Trizol resulted in the highest RNA yield of all preparations analyzed. To conclude, both protocols are suitable for RNA isolation. Trizol is recommended if higher yields are the primary concern, but RNeasy is recommended if time is an issue.The marine environment is a rich source of structurally unique natural products with bioactive metabolites that are being developed as therapeutic agents. Over 12,000 novel marine natural products have been discovered over the past

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We recently reported that the biosynthesis of fuscol, a diterpene from the octocoral Eunicea fusca, is inducible by the application of plant signaling factors such as salicylic acid to the coral's algal symbiont. In this study, an mRNA differential display approach has been employed with the dinoflagellate symbiont of this octocoral which has led to the isolation of a farnesyldiphosphate synthase (FPPS) that was transcriptionally activated under conditions that led to an induction of fuscol biosynthesis. Using a degenerate primer based on the aspartate-rich motifs found in prenylsynthases and a cassette ligation strategy, we report the cloning of the complete FPPS associated with the E. fusca dinoflagellate symbiont Symbiodinium sp. The protein exhibited the enzymatic properties associated with FPPS, namely, the synthesis of farnesyl diphosphate from geranyldiphosphate and isopentenyl diphosphate. The amino acid sequence of this FPPS has a high sequence similarity (82%) to known archaeal isoprenyl diphosphate synthases. This is the first description of a prokaryotic FPPS derived from a marine source.

Transcriptomic studies of marine organisms are still in their infancy. A partial, subtracted expressed sequence tag (EST) library of the Caribbean octocoral Erythropodium caribaeorum and the sea fan Gorgonia ventalina has been analyzed in order to find novel genes or differences in gene expression related to potential secondary metabolite production or symbioses. This approach entails enrichment for potential non-"housekeeping" genes using the suppression subtractive hybridization (SSH) polymerase chain reaction (PCR) method. More than 500 expressed sequence tags (ESTs) were generated after cloning SSH products, which yielded at least 53 orthologous groups of proteins (COGs) and Pfam clusters, including transcription factors (Drosophila Big Brother), catalases, reverse transcriptases, ferritins and various "hypothetical" protein sequences. A total of 591 EST sequences were deposited into GenBank [dbEST: FL512138 -FL512331, GH611838, and HO061755-HO062154]. The results represent proof of concept for enrichment of unique transcripts over housekeeping genes, such as actin or ribosomal genes, which comprised approximately 17% of the total dataset. Due to the gene and sequence diversity of some ESTs, such sequences can find utility as molecular markers in current and future studies of this species and other soft coral biogeography, chemical ecology, phylogenetics, and evolution.