第四十二期水木清华生命科学讲座系列
赵进东教授1956年出生于中国重庆市，1982年1月毕业于西南师范大学。1990年1月获得美国University of Texas at Austin博士学位。赵进东教授现在为北京大学生命科学学院教授，中国科学院水生生物研究所研究员，所长。
自1994年以来，赵进东教授主要从事蓝藻细胞分化和格式形成（pattern formation）研究。赵进东教授领导的实验室发现了若干关键基因在细胞分化和格式形成中的作用机理。他们同时还发现多细胞蓝细菌细胞-细胞物质交流通道形成的分子机理，从而揭示细胞通讯在格式形成中的重要作用。赵进东教授曾获得多项国家奖励，于2007年被遴选为中国科学院院士。
Topic: Multicellularity of cyaobacteria: cellular communication and pattern formation
Speaker:
Jindong Zhao, Ph.D.
Professor, College of Life Sciences,
Peking University, Beijing
Abstract:
The cyanobacteria are a group of prokaryotes that perform oxygen-evolving photosynthesis and they were responsible for the early accumulation of oxygen on earth. The cyanobacteria were the first group of organisms with multicellular organization in evolution. Multicellularity is one of the few key events in evolution and there are several key features in multicellularity: cell to cell adhesion, intercellular communication and cell differentiation in structure and/or functions. All three features are present in Anabaena 7120, a filamentous cyanobacterium that carries out oxygenic photosynthesis and nitrogen fixation. Under specific conditions, Anabaena 7120 forms specialized cells called heterocysts for nitrogen fixation and the heterocysts are distributed semi-regularly on the filaments (pattern formation). Studies show that the signal of lacking combined nitrogen leads to induction of the hetR gene, the master gene of heterocyst differentiation, and HetR initiates the process of differentiation. It is also found that HetR-PatS circuit is responsible for the pattern formation, which could be described by a Turing’s model. The mechanism of PatS peptide movement along the filaments was studied and we revealed that the presence of nanopores on cell septa and cytoplasmic connection through these nanopores are the routes for cell-cell communication. We examined other filamentous cyanobacteria and found that there are different stages of multicellularity in these cyanobacteria and their significance in evolution will be discussed.
时间：2016年5月25日（周三）15:30-16:30
地点：清华大学医学科学楼B323
