Scientists revive ‘zombie virus’ from nearly 50,000 years ago

WHAT YOU NEED TO KNOW:

• Vast portions of permafrost have thawed due to global warming, releasing ancient microbes that can potentially be infectious.
• Scientists revived some of these “zombie viruses” to assess their risk to public health.
• One virus, named Pandoravirus yedoma, is believed to be 48,500 years old.

Global warming has caused vast portions of permafrost to melt, releasing ancient microbes that have been trapped for millennia.

Scientists revived some of these so-called “zombie viruses” from the Siberian permafrost to better study them. One virus, believed to be about 50,000 years old, has reanimated to a state capable of infecting other organisms.

Microbiologist Jean-Marie Alempic of the French National Centre for Scientific Research led the research team behind the study.

The team noted that permafrost covered “one-quarter of the Northern Hemisphere.” As this frozen ground thaws, previously frozen organic matter is released. These would then “decompose into carbon dioxide and methane, further enhancing the greenhouse effect.”

Rising temperatures have previously released huge numbers of bacteria into the environment, although these are less threatening given the current antibiotics. But a new virus, such as SARS-CoV-2, will cause more problems, considering the growing population in the Arctic.

The team warned that “the revival of an ancient unknown virus” could pose a significant threat to public health, thereby necessitating further study to assess “the risk of ancient viral particles remaining infectious and getting back into circulation.”

As the permafrost thaws, many more viruses will be released, aside from those that only target amoebas. Most of these will be completely unknown to science, but it’s also unknown how infectious they are once exposed to light, heat, and oxygen. Further study can look into this.

The researchers detailed 13 viruses in their new study. Nine of them are believed to be tens of thousands of years old, with one amoeba virus believed to be 48,500 years old. They stated that each one’s genome was distinct from all other known viruses.

The record-breaking find was extracted beneath a lake. Other microbes were found on mammoth wool and in a Siberian wolf’s intestines, which were all buried underneath the permafrost.

The researchers used live single-cell amoeba cultures in proving that the viruses could still become infectious.

The new virus was assigned the name Pandoravirus yedoma, given its size and the type of permafrost soil it was found in. The researchers previously discovered a similar virus, believed to be about 30,000 years old, in Siberia. That was also a pandoravirus, which is big enough to be seen using light microscopy.

Virologist Eric Delwart of the University of California, San Francisco, who wasn’t involved in the study, also believes that these finds are just the beginning.

Having plenty of experience with reanimating ancient plant viruses, Delwart told New Scientist, “If the authors are indeed isolating live viruses from ancient permafrost, it is likely that the even smaller, simpler mammalian viruses would also survive frozen for eons.”

The new study, which has yet to be peer-reviewed, was published on bioRxiv.

Source: Science Alert