Our paper, “Glassy dynamics in models of confluent tissue with mitosis and apoptosis” just appeared in Soft Matter.
Recent work on particle-based models of tissues has suggested that any finite rate of cell division and cell death is sufficient to fluidize an epithelial tissue. At the same time, experimental evidence has indicated the existence of glassy dynamics in some epithelial layers despite continued cell cycling. To address this discrepancy, we quantify the role of cell birth and death on glassy states in confluent tissues using simulations of an active vertex model that includes cell motility, cell division, and cell death. Our simulation data is consistent with a simple ansatz in which the rate of cell-life cycling and the rate of relaxation of the tissue in the absence of cell cycling contribute independently and additively to the overall rate of cell motion. Specifically, we find that a glass-like regime with caging behavior indicated by subdiffusive cell displacements can be achieved in systems with sufficiently low rates of cell cycling.
The BioInspired Institute held it’s kickoff event on October 11, featuring PI pitch talks, a brainstorming session, and a poster session for students and postdocs. At the poster session Julia and Ethan were awarded prizes for the presentation of their respective work entitled “Predicting crowd dynamics using local structure” and “Structural evolution of amorphous systems during large scale deformation.”
Read more about the BioInspired Institute here:
Lisa was named a 2019 APS Fellow, for “microscopic theory of flow and rigidity in disordered and biological materials”, from the Division of Condensed Matter Physics. More information about the award can be found here:
On October 4, 2019, Lisa attended the UC Santa Barbara Alumni Awards reception ( https://www.ucsbalum.com/events/awards/alumni-awards-dinner ) and received the “Emerging Leader” award, for her “early career achievements in physics research and her commitment to advancing STEM to diverse audiences.”
We have posted a manuscript on BioRXiv: Xun Wang*, Matthias Merkel*, Leo B. Sutter*, Gonca Erdemci-Tandogan, M. Lisa Manning, Karen E. Kasza. “Anisotropy links cell shapes to a solid-to-fluid transition during convergent extension”, https://doi.org/10.1101/781492 (2019). In this manuscript we use a combination of vertex models and experimental analysis of convergent extension in the fruit fly to understand how the fluid-solid transition is affected by anisotropic stresses.
We posted a joint manuscript between the Manning group (Sussman, Manning) and the Gardel lab (Devaney, Gardel) on BioRXiv, titled, “Cell division Rate Controls Cell Shape Remodeling in Epithelia”, https://www.biorxiv.org/content/10.1101/804294v1. We use a combination of vertex modeling and experiments to demonstrate that cell shape (and not number density) governs cell movements in epithelia, and that cell divisions generate the dominant active stress fluctuations that cause cell movements.
Liz was accepted to study at the 2019 Boulder Summer School for Theoretical Biophysics. The program provides education for advanced graduate students and postdoctoral fellows working in condensed matter physics, materials science and related fields. Liz will be presenting her preliminary work on cellular tissues and morphogen gradients and Dr. Manning will give lectures on topics in soft matter and biophysics.
Work done by undergraduate SBI REU student Janice Kang and her graduate mentor Preeti Sahu on quantifying the nature of the rigidity transition in models for ordered biological tissues – ‘Non-linear analysis of the fluid-solid transition in a model for ordered biological tissues’ by Preeti Sahu, Janice Kang, Gonca Erdemci-Tandogan and M. Lisa Manning is now posted on ArXiv.
Julia was accorded an Honorable Mention in the 2019 National Science Foundation (NSF) Graduate Research Fellowship Program (GFRP) competition. Her application discussed novel models for the physics of living systems. See the SU News Article: Students Earn 2019 National Science Foundation Awards.
An abstract for contributed talk on work done by Preeti Sahu, Janice Kang, Gonca Erdemci-Tandogan, and Lisa Manning on understanding “the nature of the rigidity transition in models for ordered biological tissues” got upgraded to an invited talk for the session “Statistical Physics of Large Populations of Cells: from Microbes to Tissues II” in APS March meeting 2019. [Link]