Molecular approach to biomedicinals from photosymbionts of marine invertebrates

A phylogenetic tree was generated that illustrates the affiliation of the partial 16S rRNA gene sequence from a clone of the uncultured cyanobacterium symbiont of the sponge Ircinia ramosa. The partial 16S rRNA gene sequence derived from this clone is available from the EMBL/GenBank/DDBJ nucleotide sequences database under Accession No. EF467662. To consider the use of molecular techniques for searching and identifying key biosynthetic genes from the currently non-culturable microbial consortia.To examine the ecological role and metabolic cost to the algal producer for the biosynthesis of such a vast array of often complex secondary metabolites. Prochlorococcus marinus (AE017162, AF001469, AF001470, AF001471, AF001474, AF053397, AF053399, AF115268, AF115270, AF180967, AF311217, AF311220, BX572095, BX572090, BX572100, X63140); Synechococcus sp. (AF001480, AF216950, AF317073, AF330249, AF330250, AF330251, AF448060, AF448063, AF448067, AY172801, AY172802, AY172803, AY172804, AY172806, AY172807, AY172808, AY172809, AY172810, AY172832, AY210409, AY224198, BX569694); Cyanobacterium symbiont of Ircinia ramosa (EF467662); Cyanobacterium symbionts of Xestopongia exigua (AY692243, AY692244, AY692245); Cyanobacterium symbiont of Aplysina aerophoba (AJ347056).

本研究构建了一套系统发育树，用以阐明海绵*Ircinia ramosa*的未培养蓝细菌共生体克隆株所携带的部分16S核糖体RNA基因序列的分类归属关系。该克隆株获得的部分16S核糖体RNA基因序列，可从欧洲分子生物学实验室/基因银行/日本DNA数据库（EMBL/GenBank/DDBJ）的核苷酸序列数据库中获取，登录号为EF467662。本研究旨在达成两大核心目标：其一，探索利用分子技术从当前尚无法体外培养的微生物群落中检索并鉴定关键生物合成基因的可行方案；其二，探明藻类生产者合成大量结构复杂的次级代谢产物时所承担的生态作用与代谢成本。本次研究涉及的参考序列信息如下：1. 原绿球藻（*Prochlorococcus marinus*）：AE017162、AF001469、AF001470、AF001471、AF001474、AF053397、AF053399、AF115268、AF115270、AF180967、AF311217、AF311220、BX572095、BX572090、BX572100、X63140；2. 聚球藻属（*Synechococcus* sp.）：AF001480、AF216950、AF317073、AF330249、AF330250、AF330251、AF448060、AF448063、AF448067、AY172801、AY172802、AY172803、AY172804、AY172806、AY172807、AY172808、AY172809、AY172810、AY172832、AY210409、AY224198、BX569694；3. 海绵*Ircinia ramosa*的蓝细菌共生体：EF467662；4. 海绵*Xestopongia exigua*的蓝细菌共生体：AY692243、AY692244、AY692245；5. 海绵*Aplysina aerophoba*的蓝细菌共生体：AJ347056。