报告主题：昼夜更替调控海洋病毒和原绿球藻的相互作用

主讲人：曾庆璐副教授（香港科技大学）

主持人：李猛特聘教授

时间：2023年5月26日周五11:00

地点：致知楼706

报告摘要：

Diurnal rhythms are ubiquitous in living organisms as basic adaptations to the light–dark cycles on Earth. They are also exploited as defensive mechanisms in host–parasite interactions, and parasite infestation is known to be enhanced by disruption of the host’s circadian clock. However, to what extent and how the host and parasite influence their opponent’s diurnal rhythms are not well understood. The marine cyanobacterium Prochlorococcus is the smallest but most abundant phototroph on the planet. Previously, we reported on cyanophages that infect Prochlorococcus as the first viral model that exhibits a diurnal rhythm and identified their distinct night-infection strategies. P-SSM2 adopts an intermediate strategy, as it can adsorb to the host in the dark but will not replicate without light. In diel cycles, the diurnal rhythm compels most P-SSM2 to infect their hosts at night. Although P-SSM2 did not replicate, transcribe, or interfere with host fundamental physiology under dark, phage transcription and replication were enhanced in the following day of night infection. This finding can be explained by the repressed transcriptional activity of the host circadian clock and metabolic pathways in the context of P-SSM2 day infection, while the host transcriptional rhythm was maintained in night infection. The phosphorylation dynamics of the host central circadian clock protein KaiC was also conserved in P-SSM2 night infection. The diurnal rhythm of P-SSM2 drives P-SSM2 to select a night infection strategy, and the maintenance of the host rhythm during night infection underpins the competitiveness and fitness of P-SSM2 in the natural environment.

嘉宾简介：

曾庆璐博士现为香港科技大学海洋科学系副教授，博士生导师。主要研究蓝细菌和噬菌体在海洋生态系统中的相互作用、噬菌体的昼夜侵染节律以及侵染过程对海洋碳磷循环的影响。2003年于中山大学获得理学学士学位，2008年于美国纽约州立大学奥尔巴尼分校（SUNY at Albany）获得生物学博士学位，2008-2012年在美国麻省理工学院开展博士后研究工作。已发表SCI论文40多篇，其中多篇发表在PNAS，Current Biology，ISME J, mBio等期刊。主持多项国家自然科学基金面上项目、重大研究计划项目。