Seminar Colour Guide:              
External Faculty Speaker
Friday, 3 December 2021, 11:00Add to calendarThe many bits of positional informationGasper Tkacik, Institute of Science and Technology, Austria, AustriaHost: Justin CrockerLarge Operon, EMBL Heidelberg
Abstract: Half a century after Lewis Wolpert’s seminal conceptual advance on how cellular fates distribute in space, I provide a brief perspective on how the concept of positional information emerged and influenced the field of developmental biology and beyond. I focus on a modern interpretation of this concept in terms of information theory, largely centered on its application to cell specification in the early Drosophila embryo. I’ll argue that a true physical variable (position) is encoded in local concentrations of patterning molecules, that this mapping is stochastic, and that the processes by which positions and corresponding cell fates are determined based on these concentrations need to take such stochasticity into account. With this approach, we can shift the focus from biological mechanisms, molecules, genes and pathways to quantitative systems-level questions: where does positional information reside, how it is transformed and accessed during development, and what fundamental limits it is subject to?
Seminar given by an external postdoc
Friday, 3 December 2021, 14:00Add to calendarStochastic dynamics of cell shape during cellular state transitionsWolfram Ponisch, University of Cambridge, UK, United KingdomHost: Mindy Liu Perkinsvia Zoom VC, EMBL Heidelberg
Abstract: The development of an organism is characterized by a series of cellular state transitions where cells become increasingly specialized. For many animal cells, state transitions are accompanied by shape changes, indicating a coupling between cell shape and fate. Here, we present a pipeline to quantify and analyse cell shapes as cells undergo state transitions. First, we apply the pipeline to investigate how the notochord forms during the development of amphioxus: a basally branching chordate. We quantify and compare the shapes of thousands of cells from fixed embryos at different developmental stages, enabling us to infer the morphological trajectories of individual cells as a function of location within the notochord. By spatially mapping these trajectories, we identify conspicuous regional variation, both in developmental timing and trajectory topology. While analysing fixed samples provides us insights into the developmental dynamics of tissues, it only gives us limited access to the underlying dynamics of individual cells, e.g. the role of shape fluctuations during cell state transitions. For this reason, we apply our analysis pipeline to live movies of the epithelial-to-mesenchymal transition (EMT) of MDCK cells. We find that cell morphology is closely associated with their state: While epithelial cells display spherical shapes, mesenchymal cells undergo spreading. By tracking cells, we extract shape trajectories of individual cells and describe the evolution of cellular shape during the EMT as a stochastic process. With the help of our pipeline, we can integrate morphometric analysis into studies of cellular state transitions, allowing us to better understand the dynamic crosstalk between cell state and shape.
External Faculty Speaker
Tuesday, 7 December 2021, 15:00Add to calendarMechanomicrobiology: how bacteria sense and respond to forces Alexandre Persat, Persat Lab, EPFL Lausanne, Switzerland, SwitzerlandHost: Nassos TypasSmall Operon, EMBL Heidelberg
Abstract: Passcode: 610928
Seminar given by an external postdoc
Wednesday, 8 December 2021, 14:00Add to calendarArchitecture of the retroviral capsid explored by cryo-electron tomography and subtomogram averagingMartin Obr, IST Austria, AustriaPasscode: 382397Host: Simone MatteiSmall Operon, EMBL Heidelberg
Abstract: Join Zoom Meeting Meeting ID: 934 0022 3509 Passcode: 382397 Abstract: Family Retroviridae comprises viruses infecting wide range of hosts, including humans (Human immunodeficiency virus; Human T-lymphotropic virus). The life cycle of retroviruses contains several unique steps, one of which is proteolytic maturation. During this process, the immature virus particle is converted to mature. Particularly, the precursor protein Gag is cleaved to yield Capsid protein, which triggers large-scale structural reorganization of the virus particle. Capsid protein, and the corresponding part of Gag, form and maintain the protein lattice, which constitutes the mature and immature capsid, respectively. Retroviral lattice is a challenging object for structural biology, due to the absence of global symmetry. The classic techniques, such as X-ray crystallography, are thus of limited applicability. On the other hand, the versatility of cryo-electron tomography and subtomogram averaging allows observing ultrastructure of the retrovirus particle, and structure determination of its building blocks. Tags: Biocomputing, Structural Biology
Company Representative
Thursday, 9 December 2021, 11:00Add to calendarbeLab2122Friedrich Reinhard, EVOTEC, GermanyHost: Matthias Hentze and EMBLEMvia Zoom VC, EMBL Heidelberg
External Faculty Speaker
Monday, 13 December 2021, 10:00Add to calendarActive Processes in Biology: Observing, Describing, ControllingFlorian Berger, Division of Cell Biology, Neurobiology and Biophysics, Utrecht University, NetherlandsHost: Anna ErzbergerLarge Operon, EMBL Heidelberg
Abstract: Zoom Meeting ID: 912 4345 1610 / Passcode: 853052 “Ideas have consequences” and we use physical descriptions and computational methods to explore the consequences of our ideas about biological systems. These systems display a large variety of active processes driven by molecular motors that transduce chemical energy into mechanical work. Although we have a fairly good understanding of how molecular motors operate on a single-molecule level, it is often difficult to relate a precise physical description of these proteins to large-scale behavior. We recently introduced a quantitative framework to analyze experimental data of molecular motors in optical traps. This method allows us to systematically relate the observable quantities to molecular behavior and it provides new insight into the force production of human dynein. Furthermore, we explore the consequences of different ideas about force-producing molecular motors in the cellular context during centrosome repositioning in T cells. Here, we used large-scale simulations to show that a simple idea is consistent with experimental findings. In our most recent efforts, we explore the consequences of perturbations of active biological systems to either characterize their non-equilibrium behavior or to realize closed-loop control. Tags: Cell Biology
Career Event
Monday, 13 December 2021, 11:01Add to calendar EMBL Careers Webinar | Regulatory affairs Dr. Irene Garcia Ferrer , Regulatory Affairs Specialist, BD, FranceDr. Claudio Shah, CMC Manager, Boehringer Ingelheim Host: EMBL Fellows' Career ServiceVirtual, Virtual
Planetary Biology Lectures
Tuesday, 14 December 2021, 14:00Add to calendarBack to the past: sedimentary archives revealed dinoflagellate communities shifts and species adaptations due to human impact in the Bay of Brest (France)Raffaele Siano, IFREMER, FranceHost: Detlev ArendtVirtual, Virtual
Abstract: Join Zoom Meeting Meeting ID: 936 0817 9765 Passcode: PBLS
Planetary Biology Lectures
Thursday, 13 January 2022, 10:00Add to calendarTo be announcedFernando Maestre Gil, University of Alicante, SpainHost: James SharpeVirtual, Virtual
Abstract: Meeting ID: 936 0817 9765 Passcode: PBLS