Welcome to the Amira-Avizo Software Use Case Gallery

Ebola viruses (EBOVs) assemble into filamentous virions, whose shape and stability are determined by the matrix viral protein 40 (VP40). Virus entry into host cells occurs via membrane fusion in late endosomes; however, the mechanism of how the remarkably long virions undergo uncoating, including virion disassembly and nucleocapsid release into the cytosol, remains unknown. Here, we investigate the structural architecture of EBOVs entering host cells and discover that the VP40 matrix disassem... Read more

Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. Researchers developed prostate-specific membrane antigen (PSMA)–targeted low-molecular-weight agents for 212Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate.

Targeted radiopharmaceutical therapy using α-particles (α-TRTs), which cause deposition of ionizing radiation of high-linear-ener... Read more

Cortical bone is permeated by a system of pores, occupied by the blood supply and osteocytes. With ageing, bone mass reduction and disruption of the microstructure are associated with reduced vascular supply. Insight into the regulation of the blood supply to the bone could enhance the understanding of bone strength determinants and fracture healing. Using synchrotron radiation-based computed tomography, the distribution of vascular canals and osteocyte lacunae was assessed in murine cortica... Read more

Amira capacities for membranes and filaments segmentation in cryo-TEM images are featured on the front cover of Biochemical Journal, July 2020.

Budding yeast septins are essential for cell division and polarity. (…) [The authors] have dissected, here, for the first time, the behavior of the Shs1 protomer bound to membranes at nanometer resolution, in complex with the other septins. Using electron microscopy, [the authors] have shown that on membranes, Shs1 protomers self-assembl... Read more

High-resolution 3D images of organelles are of paramount importance in cellular biology. Although light microscopy and transmission electron microscopy (TEM) have provided the standard for imaging cellular structures, they cannot provide 3D images.

However, recent technological advances such as serial block-face scanning electron microscopy (SBF-SEM) and focused ion beam scanning electron microscopy (FIB-SEM) provide the tools to create 3D images for the ultrastructural analysis of org... Read more

Sarcomeres are force-generating and load-bearing devices of muscles. A precise molecular picture of how sarcomeres are built underpins understanding their role in health and disease. Here, we determine the molecular architecture of native vertebrate skeletal sarcomeres by electron cryo-tomography.

Our reconstruction reveals molecular details of the three-dimensional organization and interaction of actin and myosin in the A-band, I-band, and Z-disc and demonstrates that α-actinin cros... Read more

Cells contain hundreds of different organelle and macromolecular assemblies intricately organized relative to each other to meet any cellular demands. Obtaining a complete understanding of their organization is challenging and requires nanometer-level, three-dimensional reconstruction of whole cells. Even then, the immense size of datasets and large number of structures to be characterized requires generalizable, automatic methods.

To meet this challenge, we developed an analy... Read more

Cortese et al. use integrative imaging techniques to generate a publicly available repository of morphological alterations induced by SARS-CoV-2 in lung cells. Accumulation of ER-derived double-membrane vesicles, the viral replication organelle, occurs concomitantly with cytoskeleton remodeling and Golgi fragmentation. Pharmacological alteration of cytoskeleton dynamics restricts viral replication and spread.

Pathogenesis induced by SARS-CoV-2 is thought to result from both an inflamma... Read more

Accumulating evidence indicates the critical importance of cerebrovascular dysfunction in the pathogenesis of Alzheimer’s disease (AD). However, systematic comparative studies on the precise brain vasculature of wild-type and AD model mice are still rare. Using an image optimization method for analyzing Micro-Optical Sectioning Tomography (MOST) data, we generated cross-scale whole-brain 3D atlases that cover the entire vascular system from large vessels down to smallest capillaries at ... Read more

Recent treatment developments for metastatic renal cell carcinoma offer combinations of immunotherapies or immunotherapy associated with tyrosine kinase inhibitors (TKI). There is currently no argument to choose one solution or another. Easy-to-use markers to assess longitudinal responses to TKI are necessary to determine when to switch to immunotherapies. These new markers will enable an earlier adaptation of therapeutic strategy in order to prevent tumor development, unnecessary toxicity an... Read more

Cell-to-cell contact is essential for communication and development of multicellular organisms. A prerequisite is the passage through membranes. That way, molecular exchange and information flow is regulated via hormones, membrane proteins and pores.
In plants, the rigid cell walls prevent large membrane contact areas between protoplasts. Only plasmodesmata, minute channels between adjacent cells, form direct connections. Often, molecular data of the proteins involved are manifold but t... Read more

Actin waves are dynamic supramolecular structures involved in cell migration, cytokinesis, adhesion, and neurogenesis. Although wave-like propagation of actin networks is a widespread phenomenon, the actin architecture underlying wave propagation remained unknown. In situ cryo-electron tomography of Dictyostelium cells unveils the wave architecture and provides evidence for wave progression by de novo actin nucleation. Subtomogram averaging reveals the structu... Read more

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the COVID19 pandemic, is a highly pathogenic β-coronavirus. As other coronaviruses, SARS-CoV-2 is enveloped, replicates in the cytoplasm and assembles at intracellular membranes. Here, we structurally characterize the viral replication compartment and report critical insights into the budding mechanism of the virus, and the structure of extracellular virions close to their native state by in situ cryo-electr... Read more

Since its invention and commercialization in the 1950s, ultra-high molecular weight polyethylene (UHMWPE) has been known as a high-performance polymer successfully applied in diverse engineering systems ranging from strong ropes for naval demands and wear-resistant liners in bearings, transportation belts and heavy trucks in mines and quarries, through the lining of chemical vessels and disposable bags in bioreactors, to sophisticated products such as orthopaedic implants and replacements of ... Read more

An elemental sulfur electrode was imaged with X-ray micro and nano computed tomography and segmented into its constituent phases. Morphological parameters including phase fractions and pore and particle size distributions were calculated directly from labelled image data, and flux based simulations were performed to determine the effective molecular diffusivity of the pore phase and electrical conductivity of the conductive carbon and binder phase, D... Read more

HIV-1 maturation occurs via multiple proteolytic cleavages of the Gag polyprotein, causing rearrangement of the virus particle required for infectivity. (…) How individual cleavages contribute to changes in protein structure and interactions, and how the mature, conical capsid forms, are poorly understood. Here, we employed cryoelectron tomography to determine morphology and high-resolution CA lattice structures for HIV1 derivatives in which Gag cleavage sites are mutated. These analyse... Read more

COPI-coated vesicles mediate trafficking within the Golgi apparatus and from the Golgi to the endoplasmic reticulum. Here, we applied cryo-focused ion beam milling, cryo-electron tomography and subtomogram averaging to determine the native structure of the COPI coat within vitrified Chlamydomonas reinhardtii cells. The native algal structure resembles the in vitro mammalian structure, but additionally reveals cargo bound beneath beta’–COP. We find that all coat components disassemble... Read more

Protein aggregation and dysfunction of the ubiquitin-proteasome system are hallmarks of many neurodegenerative diseases. Here, we address the elusive link between these phenomena by employing cryo-electron tomography to dissect the molecular architecture of protein aggregates within intact neurons at high resolution. We focus on the poly-Gly-Ala (poly-GA) aggregates resulting from aberrant translation of an expanded GGGGCC repeat in C9orf72, the most common genetic cause of amyotrophic latera... Read more

Correlative light and electron microscopy (CLEM) is a powerful approach to investigate the molecular ultrastructure of labeled cell compartments. However, quantitative CLEM studies are rare, mainly due to small sample sizes and the sensitivity of fluorescent proteins to strong fixatives and contrasting reagents for EM. Here, we show that fusion of…

During the acts of biting and chewing, the muscles of the jaw (consisting of the masseter, temporalis, and medial pterygoid in the elevator group, and lateral pterygoid as the main depressor) generate forces that dictate jaw kinematics . The movement of jaws hinges about the temporomandibular joint and are brought together by the muscles attached to respective bones through bone-tendon interfaces known as entheses . Thus, chewing forces affect aspects of craniofacial structure as well as bo... Read more

The tissue inhibitor of metalloproteinases-1 (TIMP-1) exerts inhibitory activity against matrix metalloproteinases and cytokine-like effects. We previously showed that TIMP-1 reduces neurite outgrowth in mouse cortical neurons and that this cytokine-like effect depends on TIMP-1 endocytosis mediated by the low-density lipoprotein receptor-related protein-1 (LRP-1). To gain insight into the interaction between TIMP-1 and LRP-1, we considered conformational changes that occur when a ligand bind... Read more