title: Diversity of virus-host systems in hypersaline Lake Retba, Senegal.
abstract: Remarkable morphological diversity of virus-like particles was observed by transmission electron microscopy in a hypersaline water sample from Lake Retba, Senegal. The majority of particles morphologically resembled hyperthermophilic archaeal DNA viruses isolated from extreme geothermal environments. Some hypersaline viral morphotypes have not been previously observed in nature, and less than 1% of observed particles had a head-and-tail morphology, which is typical for bacterial DNA viruses. Culture-independent analysis of the microbial diversity in the sample suggested the dominance of extremely halophilic archaea. Few of the 16S sequences corresponded to known archeal genera (Haloquadratum, Halorubrum and Natronomonas), whereas the majority represented novel archaeal clades. Three sequences corresponded to a new basal lineage of the haloarchaea. Bacteria belonged to four major phyla, consistent with the known diversity in saline environments. Metagenomic sequencing of DNA from the purified virus-like particles revealed very few similarities to the NCBI non-redundant database at either the nucleotide or amino acid level. Some of the identifiable virus sequences were most similar to previously described haloarchaeal viruses, but no sequence similarities were found to archaeal viruses from extreme geothermal environments. A large proportion of the sequences had similarity to previously sequenced viral metagenomes from solar salterns.
authors.affiliation: Laboratoire Microorganismes: Génome et Environnement, Université Blaise Pascal (Clermont-Ferrand II), UMR CNRS 6023, F-63177, Aubière Cedex, France.
authors.forename: Télesphore
authors.initials: T
authors.lastname: Sime-Ngando
authors.forename: Soizick
authors.initials: S
authors.lastname: Lucas
authors.forename: Agnès
authors.initials: A
authors.lastname: Robin
authors.forename: Kimberly Pause
authors.initials: KP
authors.lastname: Tucker
authors.forename: Jonathan
authors.initials: J
authors.lastname: Colombet
authors.forename: Yvan
authors.initials: Y
authors.lastname: Bettarel
authors.forename: Elie
authors.initials: E
authors.lastname: Desmond
authors.forename: Simonetta
authors.initials: S
authors.lastname: Gribaldo
authors.forename: Patrick
authors.initials: P
authors.lastname: Forterre
authors.forename: Mya
authors.initials: M
authors.lastname: Breitbart
authors.forename: David
authors.initials: D
authors.lastname: Prangishvili
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000821:virology*; D023641:Archaeal Viruses / Q000145:classification* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000821:virology*; D001435:Bacteriophages / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000648:ultrastructure*; D044822:Biodiversity; D004783:Environmental Microbiology; D060106:Lakes / Q000382:microbiology / Q000821:virology; D054892:Metagenome; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D012675:Senegal
chemical_list: D012336:RNA, Ribosomal, 16S