Pithovirus

Pithovirus is a genus of giant viruses discovered in 2013. It is one of the largest viruses known, with a genome size and particle volume significantly larger than other viruses. The first species identified, Pithovirus sibericum, was found in ancient permafrost samples from Siberia, leading to speculation about its potential for revival and the implications for ancient microbial life.

Pithovirus particles are ovoid in shape and measure approximately 1.5 micrometers in length, making them visible under a light microscope. Their genome is also exceptionally large, containing millions of base pairs and hundreds of genes, many of which code for functions typically associated with cellular life, such as protein synthesis. This complexity has led to debate about the classification of pithoviruses and their place in the tree of life, with some scientists suggesting they blur the lines between viruses and cellular organisms.

Despite their size and genetic complexity, Pithovirus are obligate intracellular parasites. They infect amoebas, specifically Acanthamoeba species, and replicate within their host cells. The discovery of Pithovirus has expanded our understanding of viral diversity and the potential for novel biological entities in extreme environments. Further research is ongoing to fully characterize Pithovirus and its evolutionary significance.