ZBP Colloquium

Intro

The colloquium of the Center for Biophysics takes place in a monthly rhythm during the lecture period:

  • Time: Thursdays from 14:00 to 16:00
  • Location building C6 4, lecture hall II

Upcoming talks

ZBP Colloquium

Prof. Dr. T.-Y. Dora Tang. (Universität des Saarlandes)
Title: From molecules to life: building living systems from scratch
Time: 14:15 (refreshments at 14:00)
Location: Campus SB, Building C6 4, room 0.09 (Hörsaal II)

Abstract: One of the goals of bottom-up synthetic biology is to build living cells from scratch. Biology is well equipped in exploiting a large number of out-of-equilibrium processes to support life. A complete understanding of these mechanisms is still in its infancy due to the complexity and number of the individual components involved in the reactions. However, a bottom-up approach allows us to replicate key biological processes using a small number of basic building blocks. Moreover, this methodology has the added advantage that properties and characteristics of the artificial cell can be readily tuned and adapted. 

In this talk, I will provide an overview of the strategies we adopt in our lab to build living systems from scratch that rely on reactions, compartments and communication as the defining feature to support out-of-equilibrium behaviour. Specifically, I will talk about the design and synthesis of artificial cells based on liquid-liquid phase separation (coacervation) and hydrophobic effects such as lipid vesicles and proteinosomes and describe how these compartments may be used as platforms for implementing life-like behaviours including: oscillations and communication. I propose that our bottom-up approaches are effective in establishing living systems from scratch and in doing so provide unique model systems that can help to unravel the physico-chemical principles of living systems. 

ZBP Colloquium

Prof. Dr. Stefan Diez. (TU Dreden)
Title: Gliding Motion of Diatoms: Of Motors, Filaments and Complex Motility Patterns
Time: 14:15 (refreshments at 14:00)
Location: Campus SB, Building C6 4, room 0.09 (Hörsaal II)

Abstract: Diatoms are one of the few eukaryotic organisms capable of gliding motility, characterized by rapid movement and quasi-instantaneous directional reversals. While previous models have proposed an actomyosin system as the force-generating mechanism, direct evidence for the involvement of actin and myosin in diatom gliding has been lacking. Additionally, the ability of rigid-walled diatoms to dynamically reorient and navigate complex environments has remained poorly understood. Here, we show that raphe-associated actin bundles, essential for diatom gliding, do not exhibit directional turnover, indicating that actin dynamics are not directly involved in force generation. Instead, we identify four raphid diatom-specific myosins (CaMyo51A-D) in Craspedostauros australis through phylogenomic analysis. Of these, only CaMyo51B-D demonstrate coordinated movement during gliding, highlighting their role in force production. Moreover, we demonstrate that diatoms achieve diverse motility patterns by dynamically switching between one- and two-raphe contact gliding, a process driven by variations in local raphe curvature and cell-substrate attachment dynamics. This dynamic-raphe-switching mechanism allows for rapid changes in path curvature and cell reorientation, particularly pronounced in smaller cells due to their increased local raphe curvature. Our findings provide novel insights into the molecular and biomechanical principles governing diatom motility, revealing how motor proteins, filament architecture, and substrate interactions coordinate to produce complex gliding behaviors.

M. G. Davutoglu, V. F. Geyer, Lukas Niese, J. R. Soltwedel, M. L. Zoccoler, R. Haase, N. Kröger, S. Diez, N. Poulsen. Gliding motility of the diatom Craspedostauros australis correlates with the intracellular movement of raphid-specific myosins. Communications Biology 7, 1187 (2024). 

S. Golfier, V. F. Geyer, N. Poulsen, S. Diez, Dynamic switching of cell-substrate contact sites allows gliding diatoms to modulate the curvature of their paths. bioRxiv 2025.03.18.643962  (2025).

Additional colloquia

Past talks

Prof. Dr. François Nédélec (Sainsbury Laboratory University of Cambridge, United Kingdom)
Title: Simple Chromosome Partioning Mechanisms and a Mitotic Spindle
Time: 4pm c.t.
Location: Campus SB, Building C6 4, Room 0.09 (Hörsaal II)
Host: Dr. Philipp Hövel

Prof. Dr. Nicolas Vandewalle. (University of Liege)
Title: Exploiting capillary interactions for assembling meso-structures
Time: 4pm c.t.
Location: Campus SB, Building C6 4, Room 0.09 (Hörsaal II)
Host: Prof. Christian Wagner