Warren symposium follows legacy of geneticist giant

If we want to understand how the brain creates memories, and how genetic disorders distort the brain’s machinery, then the fragile X gene is an ideal place to start. That’s why the Stephen T. Warren Memorial Symposium, taking place November 28-29 at Emory, will be a significant event for those interested in neuroscience and genetics. Stephen T. Warren, 1953-2021 Warren, the founding chair of Emory’s Department of Human Genetics, led an international team that discovered Read more

Mutations in V-ATPase proton pump implicated in epilepsy syndrome

Why and how disrupting V-ATPase function leads to epilepsy, researchers are just starting to figure Read more

Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more
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CLEM

Double vision: seeing viruses by both light and electron microscopy

Advances in both light and electron microscopy are improving scientists’ ability to visualize viruses such as HIV, respiratory syncytial virus (RSV), measles, influenza, and Zika in their native states.

Researchers from Emory University School of Medicine and Children’s Healthcare of Atlanta developed workflows for cryo-correlative light and electron microscopy (cryo-CLEM), which were published in the January 2017 issue of Nature Protocols.

An example of the images of viruses obtainable with cryo-CLEM. Pseudotyped HIV-1 particles undergoing endocytosis. Viral membrane = light blue. Mature core = yellow. Clathrin cages = purple. From Hampton et al Nat. Protocols (2016)

Previously, many electron microscopy images of well-known viruses were obtained by studying purified virus preparations. Yet the process of purification can distort the structure of enveloped viruses, says Elizabeth R. Wright, PhD, associate professor of pediatrics at Emory University School of Medicine.

Wright and her colleagues have refined techniques for studying viruses in the context of the cells they infect. That way, they can see in detail how viruses enter and are assembled in cells, or how genetic modifications alter viral structures or processing.

“Much of what is known about how some viruses replicate in cells is really a black box at the ultrastructural level,” she says. “We see ourselves as forming bridges between light and electron microscopy, and opening up new realms of biological questions.”

Wright is director of Emory’s Robert P. Apkarian Integrated Electron Microscopy Core and a Georgia Research Alliance Distinguished Investigator. The co-first authors of the Nature Protocols paper are postdoctoral fellows Cheri Hampton, PhD. and Joshua Strauss, PhD, and graduate students Zunlong Ke and Rebecca Dillard.

The Wright lab’s work on cryo-CLEM includes collaborations with Gregory Melikyan in Emory’s Department of Pediatrics, Phil Santangelo in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, and Paul Spearman, now at Cincinnati Children’s.

For this technique, virus-infected or transfected cells are grown on fragile carbon-coated gold grids and then “vitrified,” meaning that they are cooled rapidly so that ice crystals do not form. Once cooled, the cells are examined by cryo-fluorescent light microscopy and cryo-electron tomography. Read more

Posted on January 4, 2017 by Quinn Eastman in Immunology Leave a comment