Transfer dynamics of microbial genes among various environments : to know destiny of genes responsible for drug resistance and pathogenicity in environments.

本项目旨在了解抗药性、致病性等有害基因在不同环境中的分布，以及自然生态系统中微生物间的基因转移机制。主要研究领域为海洋环境，主要研究结果如下：1）在海洋环境细菌中发现四环素耐药基因泰特（M）和泰特（S）。这些基因仅在陆地和临床环境中有报道。本研究首次在海洋环境中发现了泰特（M）和泰特（S）等核糖体保护蛋白基因。2）在弧菌属特定种的染色体上发现了新的四环素抗性基因泰特（34）。泰特（34）基因未转移到其他物种。3）在城市河流沉积物中检测到Vero毒素基因。Vero毒素基因在沉积物中表达活跃，而在河水中表达不活跃，表明河流沉积物是Vero毒素基因转移和激活的场所。该细菌是地球上最丰富的生物，在各种环境中作为基因转移载体发挥着重要作用。5）荧光基因lux簇被划分为若干基因型，表明它们可能在不同的宿主鱼类中转移和进化。6）在许多细菌物种中发现了非特异性基因转移病毒样颗粒，它们是自然环境中的载体。7）新方法DDCS，的开发，这应该是有用的骨折细胞具有不同的物理状态。

This project aims to know distribution of hazard genes such as drug resistance and pathogenicity genes in various environment and mechanisms of the gene transfer among microbes in natural ecosystem. Main research field is marine environment.The results in this project are summarized as follows.1)Tetracycline resistance genes, tet(M) and tet(S), were found in marine environmental bacteria. These genes have been reported from only terrestrial and clinical environments. This study is the first case of discovery of ribosomal protection protein genes such as tet(M) and tet(S) in marine environments.2)Novel tetracycline resistance gene tet(34) was found to be conveyed on chromosome of specific species of genus Vibrio. The tet(34) seems to be not transferred to other species.3)Vero toxin gene was detected in urban river sediment. Gene expression of the Vero toxin gene was active in sediment rather than river water, which suggests that river sediment is the place of transfer and activation of the Vero toxin gene.4)Pseudomonas aeruginosa was found to abundantly distribute in marine environment. This bacterium should be the most abundant organism in this planet and should play important role as gene transfer vector among various environments.5)Fluorescence gene lux cluster was classified some genotypes, which are suggested to be transferred and evolved in different host fish.6)Non-specific gene transfer virus-like particles were found in many bacterial species, which are vectors among natural environments.7)New method, DDCS, was developed, which should be useful to fractionate cells having different physical states.