Discovery of two giant viruses visible to the naked eye off Brazil

Two extraordinary biological viruses!! Giant viruses visible to the naked eye and microscopic that defy classification of living beings.

The two recently discovered biological viruses have a unique mode of operation that distinguishes them from other viruses.

They are able to synthesize many types of proteins including a wide range of proteins belonging to living beings: amino acids.

This discovery raises a question that was thought to be obvious and answered. Are viruses living beings?

Discovery of two giant viruses visible to the naked eye off the coast of Brazil

Viruses are discovered in two different places. One in a sediment at the bottom of the ocean relatively close to Brazil and the other in Lake Soda, two extreme environments for this type of organism.

The team that discovered them named them tupanviruses.

Tupan or Tupa is the name that designates the god of lightning in the mythology of the Guarani people in South America.

Tupanviruses

Tupanviruses measure at least 2.3 micrometers, which is about 23 times the size of an HIV-like particle.

Giant viruses are capable of infecting many types of organisms including protists and amoebae. For humans, the tupanvirus would not represent a threat according to the researchers.

As a reminder, according to wikipedia:

A protist is a eukaryotic microorganism. It is therefore a eukaryote other than an animal (metazoan), fungus (eumycete) or plant. This group is very heterogeneous, both anatomically and physiologically. It brings together organisms with a so-called simple cellular organization, most often unicellular, sometimes multicellular, but without specialized tissues. Some are autotrophic like protophytes, some are heterotrophic like protozoa. The term protista was coined by Ernst Haeckel.

An amoeba is a microorganism belonging to various groups of eukaryotic complex cells. In the use of the term, amoeba in fact designates organisms that are members of many groups of amoeboid protists of different eukaryotic taxa: Amoebozoa, Rhizaria, Heterokonta, Excavata and Opisthokonta: it is therefore not a monophyletic group but polyphyletic. Perhaps the common ancestor of all amoebae is also the common ancestor of all eukaryotes.

Is Tupanvirus alive? ( or not )

Yes, if you don't know, viruses in general have never been considered living beings.

The genetic complexity of tupanviruses seriously challenges this categorization among scientists.

"Each tupanvirus, for example, has a large genetic instruction manual with about 1,5 million base pairs of DNA, more than some bacteria have," says co-author Bernard La Scola, a virologist at Aix-Marseille University in France.

But other scientists say giant viruses aren't all that different from their smaller relatives.

Research by Frederik Schulz, of the Department of Energy's Joint Genome Institute in Walnut Creek, California, suggests that these microscopic behemoths are regular viruses that have acquired additional genes from their hosts and should not be classified as living. .

Tupanviruses don't settle the controversy, but they challenge our preconceptions about what life is, says La Scola, the research team that made the discovery.

Source: https://www.nature.com/articles/s41467-018-03168-1