报告题目：Formation of Morphogen Gradient by Membrane-Associated Non-Receptor
报告人：清华大学周培源应用数学中心 雷锦志 研究员
报告摘要：Multiple-fate morphogen gradients are essential for embryo development. The ways that morphogens are transported from their local source to form long distance gradients can be different from one morphogen to another, or even for the same morphogen in different organ developments. This paper will focus on the mechanism by which the morphogen Dpp is transported by heparan sulfate proteoglycans (non-receptor) and study how the membrane-associated non-receptor help the morphogen form a long distance gradient. Such a mechanism has been observed for some morphogens that experience rapid turnover. We formulate here a set of reaction-diffusion partial differential equations for the dynamics of morphogen gradient formation and evolution. Under the assumption of rapid morphogen degradation, we study the existence, uniqueness, robustness and linear stability of the stationary solution. The results show that when the morphogen is highly unstable, the transport of morphogen through cell membrane associate non-receptors is a possible strategy to stabilize the morphogen, and to form distance multiple-fate gradient. Moreover, when the ligand production rate is large enough, the stationary gradient is robust with respect to a significant increase (such as magnitude doubling) of morphogen expression.