December 1, 2011

There are a lot of times when I wish I was a fly on the wall during a totally awesome experiment I’ve read about. This is not one of them, but purely for my own safety. Today, I share with you a humbling and stunning image of the deadly Marburg virus, a virus so pathogenic it requires intense special handling and facilities.

The filovirus family is made of the Ebola and Marburg viruses, which cause deadly hemorrhagic fevers in humans and non-human primates. All filoviruses are single-stranded RNA viruses, yet their range of morphologies is an obstacle in understanding the structure and assembly of these viruses. In addition, the intense containment conditions (called biosafety level 4) required to work with these viruses make many techniques either difficult or impossible. A group of biologists recently jumped over all of these hurdles to image Marburg virus particles using a variety of electron microscopy techniques. Bharat and colleagues are the first to show a detailed 3-D structure of a biosaftely level 4 pathogen, both after release and during virus assembly within an infected cell. In addition, Bharat and colleagues determined the location of different viral proteins within the virus. Above is a cryo-electron microscopy image of Marburg virus particles. All three different morphologies—filamentous, 6-shaped, and round—have spine-like protrusions coming from the virus particle membrane (arrowheads). Inset image shows striations just under the membrane in a filamentous virus particle.

Bharat, T., Riches, J., Kolesnikova, L., Welsch, S., Krähling, V., Davey, N., Parsy, M., Becker, S., & Briggs, J. (2011). Cryo-Electron Tomography of Marburg Virus Particles and Their Morphogenesis within Infected Cells PLoS Biology, 9 (11) DOI: 10.1371/journal.pbio.1001196