PANDORAVIRUS Its green its big its alien and

PANDORAVIRUS It’s green, it’s big, it’s alien and it’s not dangerous?

Why it is called “Pandoravirus” • According to Greek mythology, Pandora opened a box that had never been opened before leading to a plethora of evil things flying out and affecting the world. • Today, “to open Pandora’s box” means to perform an innocent action that has severely detrimental and far reaching negative consequences. • The new genus has been named after the Pandora's Box myth, due to its potential for far-reaching scientific consequences.

What is a Pandoravirus? • First discovered in 2013, it is the genus of a giant virus with the largest genome and physical of any known virus. • It belongs to the family Pandoraviridae. • It was first discovered by a team of French scientists led by huband wife Jean-Michel Claverie and Chantal Abergel first in Chile and then in Australia. • It is a parasite as all viruses but only infects amoeba.

Scientists • Jean-Michel Claverie is Professor of Medical Genomics and Bioinformatics at the University of Mediterranée School of Medicine, Director of the Mediterranean Institute of Microbiology, and head of the Structural and Genomic Information Laboratory. • His main current research interest is the evolutionary origin and the biology of the paradoxical giant DNA viruses. • He has around 230 publications under his name.

• Chantal Abergel is the Director of Research at CNRS and has about 100 publications under her name. • Her pioneering work has led to the discovery of several giant viruses.

Discovery • The French scientists first found the viruses in a water sample collected off the coast of Chile’s Tunquen river. The species was named Pandoravirus salinus. • Later another species named Pandoravirus dulcis was discovered in a freshwater pond in Melbourne, Australia. • The discovery was published in the “Science" magazine. • At first, owing to its giant size it was mistaken for a bacteria but later on it was confirmed to be a virus.

• Prior to these discoveries, other scientists had mistaken them for parasitic or symbiotic bacteria. • Rolf Michel, a parasitologist from Germany found a similar organism in 2008, in an amoeba living in the contact lens of a woman suffering from keratitis mistaking them for bacteria. • After the discovery of these giant viruses it was found that the description of the organism matched the newly discovered virus.

Structure • Virus particle is about 1000 nm in size. • The tegument like envelope is ~70 nm thick. • It has an ostiose like opening also measuring ~70 nm in diameter. • Lipid membrane encloses a diffused interior devoid of visible substructure. • A spherical area of electron dense material is seen episodically in reproducible fashion.

Genome • These viruses have the largest genome of all viruses. • Genome size: -P. salinus: ~2. 5 megabases P. dulcis: 1. 9 megabases. • Of the entire number of gene sequences that are coded only 7% genes match the existing database. 93% of the genes or still deciphered. • Because of this, scientists are wondering about what discoveries will be made with the deciphering of these unknown genes.

Comparison to other viruses • Viruses usually first build the protein coat first and then fill in the DNA. Pandoraviruses however carry out both the processes at the same time. • They do not contain the gene that allows them to build a protein like the capsid protein, which is the bulding block in traditional viruses. • Owing to its large genome size the complexity of these virus particles is comparable to bacteria and higher organisms rather than viruses. • Despite the differences, some similarities are observed. They contain no ribosomes, produce no energy and do not divide.

Occurrence and Interactions • As both groups of organisms, free-living amoebae and viruses, can be found in aquatic environments, there are multiple interactions with respect to host-endocytobiont relationships. • They are mostly found inside parasitized amoeba. • Pandoraviruses are known to infect mainly a certain type of amoeba known as Acanthamoeba. • They are harmless any to any other organisms including humans.

Speculations and theories • According to Greek mythology, Pandora opened a box that had never been opened before. The discovery of the Pandoravirus that has only about 6 -7% of its genes matching the existing database has led to many speculations and theories. • Scientists are curious as to what is going to be found from studying its unknown genes. • There are theories that state that Pandoraviruses may represent a previously unknown branch of the tree of life. • There are controversies about these viruses constituting the fourth domain of life.

• It is also said that these giant viruses may be a link that bridges the gap between viruses and cells. • Some scientists favour the assumption that the giant viruses have received many of their genes from their hosts or from sympatric occurring endocytobionts via lateral gene transfer. • This hypothesis would mean that this type of transfer has been an important process in the evolution of genomes in the context of the intracellular parasitic or endocytobiotic lifestyle.

As the name and the history suggests, we still have a lot to discover. And a lot to learn.

Citations http: //news. nationalgeographic. com/news/2013/07/130718 viruses-pandoraviruses-science-biology-evolution/ http: //sciencemag. org/content/341/6143/281 http: //www. pnas. org/content/111/11/4274

Video http: //www. smh. com. au/environment/pandoravirus-found-in-latrobe-uni-pond-20130726 -2 qof 0. html