Title: Self-assembly Across Scales: From Cytoskeletal Dynamics to Evolution of Multicellularity

Abstract: Self-assembly is a fundamental process that drives organization and function across biological systems, from molecular complexes to multicellular structures. In this talk, I will present our recent research on the role of self-assembly in actin cytoskeletal dynamics and the evolution of multicellularity. At the molecular scale, our work challenges the classical model of actin treadmilling through advanced single-molecule and microfluidics-assisted TIRF imaging. We have uncovered a multicomponent ecosystem at actin filament ends, where depolymerases, polymerases, and blockers interact to achieve precise spatial and temporal control of filament assembly and remodeling, reshaping our understanding of cytoskeletal self-organization. At the organismal level, I will discuss our study on the unicellular protist Stentor coeruleus, which illustrates how self-assembly may have contributed to early multicellular organization. Our findings indicate that hydrodynamic coupling between neighboring cells enhances feeding efficiency, with asymmetric benefits favoring specific individuals—a potential mechanism shedding light on the selective forces driving multicellularity. Together, these studies demonstrate how self-assembly fosters complexity and functional adaptability across scales in biological systems.

Host: Julio Monti Belmonte