Palenik B, Brahamsha B, Larimer F W, Land M, Hauser L, Chain P, Lamerdin J, Regala W, Allen E E, McCarren J, Paulsen I, Dufresne A, Partensky F, Webb E A, Waterbury J
Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202, USA.
Nature. 2003 Aug 28;424(6952):1037-42. doi: 10.1038/nature01943. Epub 2003 Aug 13.
Marine unicellular cyanobacteria are responsible for an estimated 20-40% of chlorophyll biomass and carbon fixation in the oceans. Here we have sequenced and analysed the 2.4-megabase genome of Synechococcus sp. strain WH8102, revealing some of the ways that these organisms have adapted to their largely oligotrophic environment. WH8102 uses organic nitrogen and phosphorus sources and more sodium-dependent transporters than a model freshwater cyanobacterium. Furthermore, it seems to have adopted strategies for conserving limited iron stores by using nickel and cobalt in some enzymes, has reduced its regulatory machinery (consistent with the fact that the open ocean constitutes a far more constant and buffered environment than fresh water), and has evolved a unique type of swimming motility. The genome of WH8102 seems to have been greatly influenced by horizontal gene transfer, partially through phages. The genetic material contributed by horizontal gene transfer includes genes involved in the modification of the cell surface and in swimming motility. On the basis of its genome, WH8102 is more of a generalist than two related marine cyanobacteria.
海洋单细胞蓝藻细菌约占海洋中叶绿素生物量和碳固定量的20% - 40%。在此，我们对聚球藻属（Synechococcus）菌株WH8102的240万个碱基对的基因组进行了测序和分析，揭示了这些生物适应其贫营养环境的一些方式。与典型的淡水蓝藻细菌相比，WH8102利用有机氮源和磷源，并且具有更多依赖钠的转运蛋白。此外，它似乎采取了一些策略来通过在某些酶中使用镍和钴来保存有限的铁储备，减少了其调控机制（这与公海环境比淡水环境更加稳定和缓冲的事实相符），并进化出了一种独特的游动方式。WH8102的基因组似乎受到水平基因转移的极大影响，部分是通过噬菌体。水平基因转移贡献的遗传物质包括参与细胞表面修饰和游动的基因。基于其基因组，与两种相关的海洋蓝藻细菌相比，WH8102更具通用性。
