Date: 2024-10-25 16:00-18:00 金沢大学角間キャンパス自然科学５号館２階２０９Ａ室 zoom link

Featured Speakers: Matthew Smart (Flatiron Institute), Hayden Nunley (Flatiron Institute), Ayumi Ozawa (JAMSTEC)

Title: DEDS mini-workshop: Populations of Oscillators, Organisms and Lineages (POOL)

16:00-17:00: Mathematical models in developmental biology (Matthew Smart and Hayden Nunley)

Abstract: During embryonic development, a fertilized egg gives rise to many cells which must coordinate their behavior to establish functional tissue patterns. This interplay of proliferation and patterning presents both challenges and opportunities for mathematical modeling. In this talk we focus on the patterning aspect by considering mathematical models for two distinct settings. First, motivated by the variety of stable tissue patterns reached through development, we consider networks of identical multistable cells that can self-organize into rich tissue patterns through their local interactions. Statistics of these patterns are studied numerically for the case of random cell-cell signaling. Next, we propose a model by which mechanical stress interacts with a cell fate to give rise to stable domains of different cell fates. We explore analytical and numerical solutions for this system of coupled PDEs. An interesting model prediction is confirmed by experimental data. Together these models illustrate how cell-cell interactions – both biochemical and biomechanical – can be leveraged to establish diverse multicellular patterns. We close by discussing the influence of cell proliferation on the space of stable patterns.

17:00-18:00: A system of chiral self-propelled particles as a mathematical model of animals swimming with circular trajectories (Ayumi Ozawa)

Interacting oscillatory systems can self-organize to exhibit synchronous dynamics. When each system can move in space, their interaction may yield not only temporal but also spatial order. The larvae of the aquatic animal Ciona intestinalis show circular swimming patterns. While a larva animal can swim either clockwise or counterclockwise, a population of the larvae can show order in the swimming direction. Experimental observation has also indicated that the distribution of the larvae has a nontrivial spatial structure. However, it is unclear how they achieve such spatiotemporal order. In this talk, I will introduce a system of chiral self-propelled particles as a mathematical model of swimming Ciona larvae and report their collective dynamics. Although no attractive interaction between particles is explicitly incorporated, their interaction via angular velocity results in the clustering of particles. These results may contribute to understanding the mechanism by which Ciona larvae self-organize and also provide a novel strategy for designing active matter systems.

Organizers: Hirofumi Notsu, Thomas de Jong