동해와 동중국해에서의 Synechococcus 다양성

Abstract

In order to investigate diversity of marine synechococcus strians isolated from seawater within euphotic depth of the East China Sea and the East Sea, phylogenetic analyses based on sequences of 16SrRNA gene and 16S-23S rRNA internal transcribed spacer region(ITS) and the ratio of PUB:PEB(phycorobilin:phycoerythrobilin) were investigazted for 33 culture isolates. The phylogeny of 16S rRNS gene showed that the islates were clustered into 10 clades including 2 novel and 8 previously described clades. Congruent result was obtained from a phylogenetic analysis of ITS sequences. The islated strains could be categorized into 4 types by pigment compositions - clade VIII without PUB & PEB, clade V with only PEB, clades II, IV, IX, X & XVIII with low PUB:PEB ratio, and clades III & XVIII with high PUB: PEB ratio. Interestingly, the pigment compositions of isolateds belonging to clades V and VI differe from those reported fro other oceanic regions. The presence of novel lineages and the different pigment patterns in the ECS and ES suggest the possibility that some Synechococcus lineage are distributed only in geographically resticted areas and have evolved to fit in these regions.