糖心TV

Abstract: Collective cell motion is a fundamental phenomenon at the interface of cell biology, developmental biology, and non-equilibrium physics. However, how mechanical and chemical cues are integrated at the cellular level to generate coordinated multicellular behaviours remains incompletely understood. In this talk, I will present a mechano-signalling feedback mechanism that couples ERK activity with mechanical force generation and cell movement, giving rise to robust spatiotemporal coordination observed both in vitro and in vivo. I will first review prior work establishing ERK-mediated feedback as a prototypical example of an active epithelial system, in which biochemical signalling and mechanics are dynamically intertwined. Building on this framework, I will then introduce our recent findings that reveal two distinct but coupled types of transitions governing collective dynamics: a rigidity transition, which modulates the mechanical state of the tissue, and a percolation transition, which controls the connectivity required for long-range signal propagation. I will discuss how the interplay between these transitions defines the dynamical regimes of epithelial tissues and enables the emergence of coordinated patterns of activity.

Biography: Tsuyoshi Hirashima was trained as a mathematical biologist and received his Ph.D. from Kyushu University in 2011. During his Ph.D. training, he studied mathematical modeling on tissue morphogenesis in development under the mentorship of Prof. Yoh Iwasa. He moved to Kyoto University as a JSPS postdoc research fellow and learned experimental skills in cell and developmental biology at Prof. Ryoichiro Kageyama鈥檚 lab. He then joined the faculty of Kyoto University as an Assistant Professor in 2014, a senior lecturer in 2017, and an Associate Professor at the Hakubi Center for Advanced Research in 2021. He has since joined MBI in 2022 to further pursue his scientific and personal curiosity. He has been on the editorial board of Journal of Theoretical Biology since 2022.