基于ParA-ParB-parS系统构建极性分离染色体的研究

染色体极性分离是细胞不对称分裂和分化的前提，存在于某些微生物和几乎所有高等生命体中。研究发现，染色体分离复合物系统ParA-ParB-parS 与微生物细胞极性分裂有非常密切的相关性。然而，该系统是否是染色体极性分离的充分条件或必要条件并不清楚。我们的前期工作表明， ParA-ParB-parS系统也可以在非极性分裂细胞里面发挥作用。因此，本项目拟利用合成生物学的思路，以非极性分裂的大肠杆菌为研究平台，将极性分裂的新月柄杆菌中的ParA-ParB-parS系统以及其它可能的极性元件逐步移植到大肠杆菌中，检测外源的染色体分离机器能否与大肠杆菌的染色体发生关联；进一步，微调这些元件的时空表达，最终实现具有极性染色体分离细胞的人工构建。本项目的成功将有助于发现极性染色体分离的充要功能元件，对系统地理解细胞极性构建的分子机制打下理论基础。

The separation of chromosome polarity is a prerequisite for asymmetric cell division and differentiation, and it exists in some microorganisms and almost all higher organisms. Studies have found that the chromosome separation complex system ParA-ParB-parS is very closely related to the polar division of microbial cells. However, it is not clear whether this system is a sufficient or necessary condition for chromosome polarity separation. Our previous work has shown that the ParA-ParB-parS system can also play a role in non-polar dividing cells. Therefore, this project intends to use the idea of ​​synthetic biology to gradually transplant the ParA-ParB-parS system and other possible polar elements in the polarly-divided C. crescentus as a research platform. In Escherichia coli, it is tested whether the foreign chromosome separation machine can be associated with the chromosome of Escherichia coli; further, the spatio-temporal expression of these elements is fine-tuned, and finally the artificial construction of cells with polar chromosome separation can be realized. The success of this project will help discover the necessary and sufficient functional elements for polar chromosome separation, and lay a theoretical foundation for the systematic understanding of the molecular mechanism of cell polarity construction.