Scientists discover new giant “stealthy” virus that replicates in a completely unique way

A new giant virus discovered in Japan and called stealthvirus, replicates in a way never seen before: it partially destroys the nucleus of the host cell and replicates in its remains.

A team of researchers from the Tokyo University of Science (TUS) discovered a new type of giant virus, which replicates in a way never seen before. Even more surprising, this entity could provide us with clues about the very origins of complex life.

Viruses are located outside the tree of life conventional, since they are made up of segments of genetic material and not cells, which makes it difficult to understand how they originally evolved and how they relate to living organisms.

Os giant virusesso named due to the size and complexity of their genomes, compared to those of common viruses, could help unravel this mystery.

In this new investigation, TUS microbiologists discovered a new giant virus, furtivoviruson the Inasegawa River, in the city of Kamakura, Japan.

Its name derives from the Latin word furtivus, meaning “hidden” or «stealthy», due to the initial difficulty that the team had in identifying it in the sample collected.

This discovery comes on the heels of the recent identification of other giant viruses earlier this year by some of the same researchers. Although these giants all follow the standard viral practice of taking over host cells to propagate, there are some relevant variations.

“Although these viruses belong to the same group, they use the cell nucleus in different ways,” he says Masaharu Takemuravirologist at TUS, cited by .

Two characteristics of stealthvirus make this discovery particularly special. Firstly, the new , published in Journal of Virology, suggests that this virus serves as a bridge between two related groups of giant viruses, whose genomes differ significantly in size.

The researchers propose that the furtivovirus constitutes a own viral familyto be designated by Manesviridaewhich would include other similar giant viruses.

There are differences in genome size and host selection compared to other giant viruses, as well as consistencies in DNA which, according to researchers, justifies the new classification.

As the researchers explain, furtivovirus and its proposed new family have a lot to teach us about how viruses can evolve over vast periods of time – in different sizes and with different replication methods.

Which leads us to second special feature: Your replication strategy. The other giant viruses either keep the host cell nucleus intact and replicate inside it, or they destroy the nuclear membrane and replicate in the fluid outside the nucleus. The stealthvirus adopts an intermediate tactic.

After infecting a cell, destroys the cell nucleustakes over the cell’s mechanism and replicates in what remains of the nuclear fluid. This is something that has never been observed in other giant viruses.

As far as how this all relates to complex life, the theory is that viruses could have been responsible for the original formation of the nucleus not inside the cells.

O cell nucleus distinguishes us, and other eukaryotesof organisms such as bacteria and archaea, and a hypothesis previously proposed by Takemura and other researchers postulates that giant invasive viruses could have developed the nucleus as a protection mechanism.

So where does stealthvirus fit in? This virus highlights the evolutionary path that may have been at the origin of this process – from viruses that replicate within an intact nucleus to viruses that completely destroy it, with stealthvirus somewhere between these two extremes.

Not yet a proof of the theorybut it constitutes yet another indication that viruses are capable of adapting and changing the way they use the host’s nucleus. And as our knowledge about giant viruses and their different types increases, there will undoubtedly be more discoveries to be made.