Stranger: found virus's DNA, other unknown life forms

All life on Earth is in close relationship with each other. Even in humans, and E. coli 30% of the genes are shared, and much more related to each other organisms share common genes is much higher. But recently biologists have discovered the virus DNA which simply has no analogues. More than 90% of its genes do not occur in any other virus.

the Discovery is described in the Preprint scientific articles published on the website biorXiv.org.

a Team of scientists from Brazil, France and the United States was engaged in a virus-borne amoebae. To do this, they studied protozoa that live in the waters of the artificial lake of Pampulha in Brazil.

In the course of work researchers have discovered a very unusual virus. They called it Yaravirus brasiliensis in honor Yary (Iara) – a mythological lake of the virgin of the legends of the indigenous local residents, a kind of mermaid, nymphs or sirens.

the Genome of the new virus was a real surprise for scientists.Illustration of Boratto et al., 2020, bioRxiv.

Traverus has a diameter of about 80 nm and a genome length of about 45 thousand pairs of nucleotides, or 74 gene. These options are fairly common for viruses.

Unusual was the fact that 68 of the 74 genes are completely unknown to science. Doing a search on more than 8500 public metagenomes, experts have not found even their remote counterparts.

so, if biologists were looking for traverus content in the environment of the viral DNA, they simply wouldn’t notice it.

Interestingly, most of known virus affecting amoeba belongs to a giant. They have dimensions of hundreds of nanometers and the genomes of thousands of genes. Furthermore, giant viruses have at least some elements of the apparatus independent of protein synthesis. (Before the opening of the giants was thought that viruses have no capacity to synthesize protein and are forced to use cells of the host.)

Traverus does not apply to the giant, but the authors do not exclude that he comes from them.

By the way, before “News.Science” (nauka.vesti.ru) wrote that in populations of mammals and birds circulates 1.6 million for unknown viruses.

Text: To.Science