Bimolecular condensates exhibit aging and solid-like behaviors. These behaviors are considered under biological regulation and related to multiple diseases. In this talk, I have two short stories about the viscoelasticity of condensates. I will first present a mesoscopic model to describe the rheology of biomolecular condensates. A phase transition from a non-aging phase to an aging phase occurs when the temperature is below a critical value. In the aging phase, condensates behave as Maxwell fluids at all ages in the linear viscoelastic regime, and the viscosities increase linearly over time. Our theories are consistent with experimental observations and make general testable predictions.  

　　I will also discuss the effects of elasticity on the dissolution of biomolecular condensates. We demonstrate that the bulk stress inside condensates may prevent the condensates from dissolution. To verify our theories, we simulate the two-fluid model in which the slow component corresponding to the polymer network generates elastic stress. Moreover, we obtain a phase diagram on the stability of elastic condensates and identify a minimum bulk modulus for the condensates to be indissoluble. 

报告人简介： 

林杰， 2011年毕业于复旦大学，2016年在纽约大学取得物理学博士学位；2016-2020， 哈佛大学，博士后研究。目前任北京大学前沿交叉学科研究院研究员， 北京大学定量生物学中心研究员以及 北京大学-清华大学生命科学联合中心研究员。主要研究方向是理论生物物理 (theoretical biological physics)，近期感兴趣的问题包括 (1) 基因表达 (gene expression) 的普适规律，(2) 活性软物质物理 (soft living matter), (3) 微生物生理学 (microbial physiology)。 

邀请人：孟凡龙