Characterization of Mollivirus kamchatka , the First Modern Representative of the Proposed Molliviridae Family of Giant Viruses

Abstract

Virology has long been viewed through the prism of human, cattle, or plant diseases, leading to a largely incomplete picture of the viral world. The serendipitous discovery of the first giant virus visible under a light microscope (i.e., >0.3 μm in diameter), mimivirus, opened a new era of environmental virology, now incorporating protozoan-infecting viruses. Planet-wide isolation studies and metagenome analyses have shown the presence of giant viruses in most terrestrial and aquatic environments, including upper Pleistocene frozen soils. Those systematic surveys have led authors to propose several new distinct families, including the Mimiviridae , Marseilleviridae , Faustoviridae , Pandoraviridae , and Pithoviridae . We now propose to introduce one additional family, the Molliviridae , following the description of M. kamchatka , the first modern relative of M. sibericum , previously isolated from 30,000-year-old arctic permafrost.