两种蓝细菌中7对毒素-抗毒素系统的分析和鉴定  

Analysis and identification of seven toxin-antitoxin systems in two cyanobacteria

作　　者：林世团 王晓雪[1,2] 陈冉 LIN Shituan;WANG Xiaoxue;CHEN Ran(Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院热带海洋生物资源与生态重点实验室,中国科学院南海海洋研究所,广东广州510301 [2]中国科学院大学,北京100049

出　　处：《热带海洋学报》2022年第3期119-134,共16页Journal of Tropical Oceanography

基　　金：国家自然科学基金(31625001、91951203)。

摘　　要：蓝细菌(cyanobacteria)是一类能进行放氧光合作用的原核生物。蓝细菌生长速度较快,几乎存在于所有的陆地和水生环境中。毒素-抗毒素(toxin-antitoxin,TA)系统在原核生物中分布十分广泛,在细菌的生命活动中扮演了重要的角色如维持水平基因转移元件的稳定性以及应对环境胁迫压力等。已有的基因组分析表明,蓝细菌基因组中含有大量潜在的毒素-抗毒素系统,但是目前对蓝细菌毒素-抗毒素系统的实验鉴定仍较少。本文分别以淡水和海水代表菌株集胞藻PCC6803(Synechocystis sp.PCC6803)和聚球藻WH7803(Synechococcus sp.WH7803)为研究对象,对二者基因组上的毒素-抗毒素系统进行预测,并选取预测结果中的7对潜在的毒素-抗毒素系统进行实验验证。结果表明,集胞藻PCC6803的两对毒素-抗毒素系统BAD01932-1933和BAA18559-New ORF7中的毒素具有明显的细胞毒性。本文的研究结果有助于后续对蓝细菌毒素-抗毒素系统及其生态和生物学功能的研究。Cyanobacteria are the only oxygenic photosynthetic prokaryotes on Earth, possessing a relatively fast growth rate and prospering in a range of diverse habitats. Toxin-antitoxin(TA) systems are prevalent in prokaryotes, and play important roles in cell physiological activities including maintenance of mobile genetic elements and mediation of stress responses.Previous bioinformatic studies revealed that putative TA systems are widely distributed in the cyanobacteria genomes.However, studies of TA systems in cyanobacteria are limited. In this study, we predicted TA systems in the genomes of Synechocystis sp. PCC6803 and Synechococcus sp. WH7803, the model strains of freshwater and marine environments cyanobacteria, respectively. The toxicity test of five TA systems in PCC6803 and two TA systems in WH7803 were further implemented. We found that the ectopic expression of toxin New ORF7 and BAD01932 lead to growth inhibition in Escherichia coli host. Our study provides vital information for future study of the ecological and biological roles of TA systems in cyanobacteria.

关 键 词：毒素-抗毒素系统 蓝细菌 集胞藻PCC6803 聚球藻WH7803 

分 类 号：Q938[生物学—微生物学]