Lysogenic cyanophages; molecular mechanisms of lysogeny and their role in marine ecosystems

溶原性噬藻体；

基本信息

批准号：
09490034
负责人：
OHKI Kaori
金额：
$ 8.06万
依托单位：
Tokai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Recent studies have revealed that cyanophages are found not only in polluted waters near the coastal areas but also in clean waters such as the open ocean. These cyanophages are thought to have an important role in the regulation of cyanophyta (cyanobacterial) populations. Most of the isolated cyanophages are of the virulent type, and cells are rapidly lysed shortly after infection. The contribution of lysogenic phages to the regulation of cyanobacterial populations is unknown. The basic knowledge such as distribution of lysogenic cyanophages among marine cyanobacteria and molecular mechanisms for lysogeny are required to estimate the possible role of lysogenic cynophages in marine ecosystems. In our previous work, we found that a cyanophage had established the stable lysogeny in marine cyanobacteria, Phormidium persicinum Provasoli strain. The lytic cycle of lysogenized phage was induced by the addition of mitomicyn C or a brief UV-illumination. (1) Using the culture of P. persicinum … More cultures, I found that considerably large part of the lysogenized cyanophage were detected to be in lytic cycle in the Phormidium percicinum cultures without any artificial induction. (2) Considarably large numbers of marine Phormidium strains isolated from different areas harbored lysogenic cyanophages. Morphological characters, DNA-DNA hybridization and Western analysis of phage proteins suggested that different family of cyanophages were established the stable lysogeny in marine cyanobacteria. These results indicated that lysogenic cyanophages are ecologically important, because not only they regulated the host algal populations but also they become the source for continuous supply of free phage particles to the ambient sea waters. (3) A possible role of lysogenic cyanophage(s) in regulation of marine, aerobic diazotrophic cyanobacteria, Trichodesmium was studied using both isolated strains (NIBB 1067) and field samples collected from Caribbean Sea off Carrie Bow Cay, Belize. Trichodesmium spp. Are the most important primary producer in oligotrophic, tropical and sub-tropical oceans. The rapid cell lysis of Trichodesmium caused by the addition of mitomycin C was observed in both cultured and natural samples. Cyanophage particles were isolated from Trichodesmium NIBB1067. These results suggested that the lysogenic cyanophage(s) must play an important role in the food web of oligotrophic oceans. Less

最近的研究表明，不仅在沿海地区附近的污染水域，而且在诸如开阔的海洋之类的清洁水域中都发现了氰。这些氰载体被认为在调节蓝藻种群的调节中起重要作用。大多数孤立的氰噬细胞都是有毒的类型，并且感染后不久会迅速裂解细胞。裂解噬菌体对蓝细菌种群调节的贡献尚不清楚。需要基本知识，例如溶酶发生在海洋蓝细菌中的分布和裂解性分子机制的分布，以估计溶酶发生cyanophages在海洋生态系统中的可能作用。在我们以前的工作中，我们发现蓝粒藻类菌株，phormidium phormidium propasoli菌株已经建立了蓝色溶酶体。通过添加Mitomicyn C或短暂的紫外线刷子诱导溶酶体化噬菌体的裂解循环。（1）使用甲状腺疟原虫的培养物……更多的培养物，我发现发现大部分溶菌化的蓝糖是在phormidium percicinum培养物中的裂解循环中，而没有任何人工诱导。（2）大量从不同地区分离出的海洋phormidium菌株具有裂解性氰基。形态学特征，DNA-DNA杂交和对噬菌体蛋白的西方分析表明，在海洋氰基细菌中建立了不同的蓝粒含量。这些结果表明，溶酶发生在生态上很重要，因为它们不仅调节了宿主藻类种群，而且还成为连续向环境海水供应自由噬菌体颗粒的来源。（3）使用分离的菌株（NIBB 1067）和从贝利兹·卡里·鲍尔·贝里兹（Carrie Bow Cay Cay）收集的分离菌株（NIBB 1067）和从加勒比海off Carrie Bow Cay，Belize，Belize，使用分离的菌株（NIBB 1067）和田间样品研究，研究了溶酶发生cyanogage（S）在调节海洋，有氧十分嗜性氰基细菌中的可能作用。 Trichodesmium spp。是贫营养，热带和亚热带海洋中最重要的主要生产者。在培养和天然样品中都观察到了丝霉素C引起的毛d虫的快速细胞裂解。从trichodesmium nibb1067中分离出蓝粒颗粒。这些结果表明，溶酶发生的氰化物必须在贫营养海洋的食物网中起重要作用。较少的