EMBL Seminars

Abstract
Many living systems demonstrate exquisite sensitivity to small input signals. A tempting hypothesis is that these systems operate close to so-called bifurcation or critical points, where small signals are amplified into qualitative changes in the collective response. A common concern, however, is that proximity to such points requires fine-tuning of parameters, which seems impossible for living systems subject to intrinsic fluctuations and changing environments. Based on several distinct sensory systems, we have investigated a feedback motif that robustly maintains these systems close to their respective critical point. The key ingredient is that the collective response feeds back onto a control parameter of the dynamics. To illustrate this idea, I will mention several examples ranging from snake thermosensing to fly olfaction and will discuss the functional benefits associated with being near-critical.

Abstract
African Trypanosomes proliferate within the bloodstream and tissue spaces of mammals and can maintain a long-term infection often lasting for years. To do this, trypanosomes must avoid the host adaptive and innate immune response at the same time as acquiring nutrients from the host. There is a good understanding of how the adaptive immune response is distracted through a population survival strategy based on antigenic variation a densely packed surface coat made of a variant surface glycoprotein (VSG). There is also a strong selection pressure to prolong the survival of individual trypanosomes presumably to increase the chances of returning to a tsetse fly, the definitive host. There is rapid clearance of antibodies bound to the cell surface and a set of conserved receptors that decrease the effectiveness of complement pathways. A second set of receptors is involved in the acquisition of host macromolecular nutrients. 

Why do these conserved receptors not lead to immune clearance?  Work on how the receptors bind ligands, how trypanosomes have evolved to have a wide host range, and what happens when on ligand binding have been integrated to form a model of how they are able to form life-long infections. 

Connection details
Zoom*: https://embl-org.zoom.us/j/99010203982?pwd=eKlBm1821yrpjddaCbanN6CjooJL8y.1 

(Meeting ID: 990 1020 3982, Password: 717935)

Please note that the talk will be recorded.
*For the FAQ section, as a zoom participant, please use either the chat function (the host will read out your question) or the “raise your hand” function and turn on your microphone.

Abstract
Group leaders based in Germany, Austria, and the US, will share their experience of negotiating their group leader role. Following the speakers' introductory presentations, participants will have the opportunity to ask questions during a panel discussion. Join to gain insights into the negotiation process and how to prepare to make the most of your first group leader position!

Please register for this zoom webinar: https://embl-org.zoom.us/webinar/register/WN_NNV9KmXCRFSGCfRgqJSxEQ#/registration

Please note that the talk will be recorded.
*For the FAQ section, as a zoom participant, please use either the chat function (the host will read out your question).

Abstract
Bridging the concentration gap between the dispersed state of intrinsically disordered biopolymers and their high-concentration states relevant for cellular environment, including membrane-less organelles, as well as for food biochemistry and food technology, is a serious challenge. In this talk, I will present an approach based on the conventional and newly developed pulse EPR techniques and aimed to describe the spatial and conformational distributions in biomolecular condensates and weak aggregates. This methodology can potentially also shed light on the biomolecules’ solvation. Furthermore, comparison of pulse EPR data with small angle scattering and THz calorimetry data might appear very interesting. Importantly, new EPR method to determine local biopolymer density will be presented, which might appear an efficient support for SAXS/SANS based determination of conformational ensembles of intrinsically disordered biomolecules.

About the speaker
[Biographical information about the speaker].

Meet the speaker
To meet with the speaker informally after the talks,sign up here [add link]. We especially encourage predocs and postdocs to take advantage of this opportunity.

Attachments
[Link to a file (for example a pdf of the seminar’s programme) - the file can be uploaded on the intranet]

Connection details
Zoom*: [link] (Meeting ID: [XXXXXXXXX], Password: [XXXXXXX])

Please note that the talk will yes/not be recorded.
*For the FAQ section, as a zoom participant, please use either the chat function (the host will read out your question) or the “raise your hand” function and turn on your microphone.

Abstract

Epigenetic components regulate many biological phenomena during development and normal physiology. When dysregulated, epigenetic components can also accompany or drive diseases. One main class of epigenetic components are Polycomb group proteins. Originally, Polycomb proteins were shown to silence gene expression. We found that this function involves the regulation of 3D chromosome folding and we found that Polycomb components can induce the formation of long-distance interactions or chromatin loops that may play instructive roles in gene regulation as well as serve as scaffolding elements that contribute to enhancer-promoter specificity. Perturbation of Polycomb components is involved in human cancer and leads to tumorigenesis in flies. Surprisingly, even upon a transient depletion followed by restoration of the full Polycomb compendium, epithelial cells lose their normal differentiated fate, continue proliferating and establish aggressive tumors, demonstrating that cancer can have a fully epigenetic origin. Similarly, transient perturbation of histone acetylation in mouse ES cells and gastruloids shows that they can record chromatin changes and that this results in cellular memory of the perturbation states. The implication of these data will be discussed.