A team of researchers from the Michigan State University shed light on enigmatic, yet captivating giant microbes that retain the ability to infect after 30,000 years. The study was published on Saturday in the journal Cell. With the help of cutting-edge imaging technologies, this study developed a reliable model for studying giant viruses and identifying and characterizing several key proteins responsible for orchestrating infection.
Giant viruses are bigger than 300 nanometers in size and can survive for many millennia. For comparison, the rhinovirus responsible for the common cold is roughly 30 nanometers.
In a report published on the university's website, principal investigator Kristin Parent, associate professor of Biochemistry and Molecular Biology at MSU, said: "Giant viruses are gargantuan in size and complexity. The giant viruses recently discovered in Siberia retained the ability to infect after 30,000 years in permafrost."
The newly discovered viruses such as the Antarctica virus, Samba virus, and Tupanviruses are covered with outer shells or capsids; they are rugged and able to withstand harsh environments, protecting the viral genome inside. These species also have a unique mechanism for releasing their viral genome.
A starfish-shaped seal sits atop one of the outer shell vertices. This unique vertex is known as the 'stargate.' During infection, the 'starfish' and 'stargate' open to release the viral genome.
The results revealed three environmental conditions that successfully induced stargate opening: low pH, high temperature, and high salt. Even more, each condition induced a different stage of infection. With this new data, the researchers designed a model to effectively and reliably mimic stages of infection for study. "This new model now allows scientists to mimic the stages reliably and with high frequency, opening the door for future study and dramatically simplifying any studies aimed at the virus," Parent said.
"We identified key proteins released during the initial stages of infection responsible for helping mediate the process and complete the viral takeover," she explained.
This article has been adapted from its original source.
