Secrets of the deadly white-tail virus revealed

The inner workings of a lethal giant freshwater prawn virus have been revealed by an international team of researchers using data gathered at Diamond Light Source. The results reveal a possible new class of virus and presents the prospect of tackling a disease that can devastate prawn farms around the world.

The detailed structure of a virus that can devastate valuable freshwater prawn fisheries has been revealed by an international team using image data collected in the Electron Bio-Imaging Centre (eBIC) based at Diamond Light Source. The researchers produced high-resolution images of virus like particles, VLP’s, composed of virus shell proteins which they compared with lower resolution images of the complete virus purified from prawn larvae. They found strong similarities between the two suggesting that the more detailed VLP images are a good representation of the intact virus. This research, exposing the inner workings of the MrNV, could make it easier to develop ways of combating the economically important disease, but also suggests that it belongs in a new, separate, group of nodaviruses.
The researchers used the rapidly developing technique of cryo-electron microscopy, cryoEM, which has the ability to produce very high-resolution images of frozen virus particles. Images so detailed that the positions of individual atoms could be inferred. Recent breakthroughs in this technique have transformed the study of relatively large biological complexes like viruses allowing researchers to determine their structures comparatively quickly. The data to produce the MrNV structure described here was captured in two days at the eBIC facility.

>Read more on the Diamond Light Source website

Image: 3D model of the MrNV
Credit: Dr David Bhella

Fighting malaria with X-rays

Today 25 April, is World Malaria Day.

Considered as one of humanity’s oldest life-threatening diseases, nearly half the world population is at risk, with 216 million people affected in 91 countries worldwide in 2016. Malaria causes 445 000 deaths every year, mainly among children. The ESRF has been involved in research into Malaria since 2005, with different techniques being used in the quest to find ways to prevent or cure the disease.

Malaria in humans is caused by Plasmodium parasites, the greatest threat coming from two species: P. falciparum and P. vivax. The parasites are introduced through the bites of infected female Anopheles mosquitoes. They travel to the liver where they multiply, producing thousands of new parasites. These enter the blood stream and invade red blood cells, where they feed on hemoglobin (Hgb) in order to grow and multiply. After creating up to 20 new parasites, the red blood cells burst, releasing daughter parasites ready for new invasions. This life cycle leads to an exponential growth of infected red blood cells that may cause the death of the human host.

The research carried out over the years at the ESRF has aimed to identify mechanisms critical for the parasite’s survival in the hope of providing an intelligent basis for the development of drugs to stop the parasite’s multiplication and spread.

>Read more on the European Synchrotron website

Image: Inside the experimental hutch of the ESRF’s ID16A nano-analysis beamlin.
Credit: Pierre Jayet