title: High-level diversity of tailed phages, eukaryote-associated viruses, and virophage-like elements in the metaviromes of antarctic soils.
abstract: The metaviromes of two distinct Antarctic hyperarid desert soil communities have been characterized. Hypolithic communities, cyanobacterium-dominated assemblages situated on the ventral surfaces of quartz pebbles embedded in the desert pavement, showed higher virus diversity than surface soils, which correlated with previous bacterial community studies. Prokaryotic viruses (i.e., phages) represented the largest viral component (particularly Mycobacterium phages) in both habitats, with an identical hierarchical sequence abundance of families of tailed phages (Siphoviridae > Myoviridae > Podoviridae). No archaeal viruses were found. Unexpectedly, cyanophages were poorly represented in both metaviromes and were phylogenetically distant from currently characterized cyanophages. Putative phage genomes were assembled and showed a high level of unaffiliated genes, mostly from hypolithic viruses. Moreover, unusual gene arrangements in which eukaryotic and prokaryotic virus-derived genes were found within identical genome segments were observed. Phycodnaviridae and Mimiviridae viruses were the second-most-abundant taxa and more numerous within open soil. Novel virophage-like sequences (within the Sputnik clade) were identified. These findings highlight high-level virus diversity and novel species discovery potential within Antarctic hyperarid soils and may serve as a starting point for future studies targeting specific viral groups.
authors.affiliation: Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa Genomics Research Institute, University of Pretoria, Pretoria, South Africa.
authors.forename: Olivier
authors.initials: O
authors.lastname: Zablocki
authors.affiliation: Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville, South Africa.
authors.forename: Lonnie
authors.initials: L
authors.lastname: van Zyl
authors.affiliation: Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa Genomics Research Institute, University of Pretoria, Pretoria, South Africa.
authors.forename: Evelien M
authors.initials: EM
authors.lastname: Adriaenssens
authors.affiliation: Genomics Research Institute, University of Pretoria, Pretoria, South Africa.
authors.forename: Enrico
authors.initials: E
authors.lastname: Rubagotti
authors.affiliation: Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville, South Africa.
authors.forename: Marla
authors.initials: M
authors.lastname: Tuffin
authors.affiliation: The International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton, New Zealand.
authors.forename: Stephen Craig
authors.initials: SC
authors.lastname: Cary
authors.affiliation: Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa Genomics Research Institute, University of Pretoria, Pretoria, South Africa don.cowan@up.ac.za.
authors.forename: Don
authors.initials: D
authors.lastname: Cowan
mesh_terms: D000864:Antarctic Regions; D001435:Bacteriophages / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D017753:Ecosystem; D056890:Eukaryota / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012526:Satellite Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012988:Soil Microbiology