Bulletin of the American Physical Society
APS March Meeting 2021
Volume 66, Number 1
Monday–Friday, March 15–19, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session V01: Visualizing the Physics Behind Cell Biology through Cryo-Electron TomographyInvited Live
|
Hide Abstracts |
Sponsoring Units: DBIO Chair: Yi-Wei Chang, University of Pennsylvania Room: 01 |
Thursday, March 18, 2021 3:00PM - 3:36PM Live |
V01.00001: Three-dimensional imaging of force-generating molecular networks inside of cells using cryo-electron tomography Invited Speaker: Matthew Swulius Dynamic networks of cytoskeletal polymers commonly take part in generating fundamental cellular forces. In order to understand the mechanical role of these cytoskeletal networks in development and disease, multimodal information across multiple dimensions and scales need to be integrated. In this presentation, I will briefly overview the protein components that make and regulate these cytoskeletal networks, and talk about how my lab is using live-cell imaging and cryo-electron tomography to study these molecules in the context of neuronal outgrowth. |
Thursday, March 18, 2021 3:36PM - 4:12PM Live |
V01.00002: Opening a new window into the cell with super-resolution imaging and in situ cryo-electron tomography Invited Speaker: Zachary Freyberg Super-resolution light and electron microscopy have revolutionized our ability to visualize cell machinery. We use live-cell super-resolution imaging including stimulated emission depletion (STED) microscopy together with highly inclined thin illumination (HiLo) and high-speed three-dimensional widefield imaging to visualize organelle dynamics in real time. We have integrated these approaches with in situ cryo- electron tomography (cryo-ET), and cryo-correlative light and electron microscopy (cryo-CLEM) to visualize the endoplasmic reticulum (ER) and its relationships with other intracellular organelles in near-native states. The combination of these methods has revealed a novel ER-derived compartment that is mobile, vesicular, and associated with mammalian 80S cytoplasmic ribosomes. Moreover, with cryo-focused-ion-beam (FIB) milling and cryo-ET, we show that these vesicles exist as discrete structures separate from the intact reticular ER architecture. We call these organelles Ribosome-Associated Vesicles (RAVs). Detailed characterization of the RAVs revealed that these structures are conserved across multiple cell types and species using both conventional transmission electron microscopy (TEM) and cryo-ET. |
Thursday, March 18, 2021 4:12PM - 4:48PM Live |
V01.00003: In-cell structural dissection of the type IVa pilus machine by cryo-electron tomography Invited Speaker: Yi-Wei Chang Cryo-electron tomography (cryoET) enables cells to be imaged in 3-dimensions in an essentially |
Thursday, March 18, 2021 4:48PM - 5:24PM Live |
V01.00004: Visualizing mitochondrial division machinery in situ Invited Speaker: Danielle Grotjahn Mitochondria are dynamic organelles that serve a variety of metabolic roles for eukaryotic cells, including ATP generation and cell signaling. Unlike other organelles, mitochondria cannot be produced “de novo”, and instead rely on a tightly regulated division process called mitochondrial fission. Several cellular stresses promote hyperactivation of the fission pathway which fragments the mitochondrial network and induces cell death (apoptosis). Despite increasing evidence that mitochondrial fragmentation is a hallmark feature of many neurodegenerative diseases, the molecular mechanisms that contribute to the mitochondrial fission process remain poorly defined. We recently developed a three-dimensional imaging approach using a combination of cryo-focused ion beam milling and cryo-electron tomography to visualize snapshots of mitochondrial constriction events in mammalian cells. Our three-dimensional reconstructions represent the highest resolution structures of the ultrastructural interactions between mitochondria and other subcellular components to date, enabling unprecedented analysis of these associations. Further analyses reveal that the endoplasmic reticulum and the cytoskeleton preferentially associate with mitochondrial membrane constrictions. Interestingly, we also observe the presence of a previously unidentified filamentous structure in association with dividing mitochondria, which we propose is a member of the septin family of cytoskeletal filaments. By mapping out the precise interactions of these components relative to mitochondrial membranes, our work describes the complete ultrastructural architecture of the mitochondrial fission machinery required for membrane constriction, and establishes cellular tomography as a valuable approach for studying snapshots of mitochondrial dynamics in situ. |
Thursday, March 18, 2021 5:24PM - 6:00PM On Demand |
V01.00005: Automatic Analysis of Cryo-Electron Tomography Using Computer Vision and Machine Learning Invited Speaker: Xu Min Cryo-electron tomography (cryo-ET) is an emerging technology for the 3D visualization of structural organizations and interactions of subcellular components at near-native state and sub-molecular resolution. Tomograms captured by cryo-ET contain heterogeneous structures representing the complex and dynamic subcellular environment. Since the structures are not purified or fluorescently labeled, the spatial organization and interaction between both the known and unknown structures can be studied in their native environment. The rapid advances of cryo-electron tomography (cryo-ET) have generated abundant 3D cellular imaging data. However, the systematic localization, identification, segmentation, and structural recovery of the subcellular components require efficient and accurate large-scale image analysis methods. We developed and adapted a suite of computer vision and machine learning methods for such analysis. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700