One of the most prominent features of archaea is the extraordinary diversity of their DNA viruses. Many archaeal viruses differ substantially in morphology from bacterial and eukaryotic viruses and represent unique virus families. For instance, viruses with bottle-shaped, lemon-shaped, coil-shaped or droplet-shaped virions are thus far exclusive to the Archaea. The distinct nature of archaeal viruses also extends to the gene composition and architectures of their genomes, and the properties of the proteins that they encode. Environmental research has revealed prominent roles of archaeal viruses in influencing microbial communities in ocean ecosystems, and recent metagenomic studies have uncovered new groups of archaeal viruses that infect extremophiles and mesophiles in diverse habitats. However, the extent of archaeal virus diversity and the ways these viruses interact with their hosts remain underexplored.
In the Cell Biology and Virology of Archaea Unit at Institut Pasteur, we are studying different aspects of viruses infecting extremophilic archaea, including hyperthermophiles, thermoacidophiles and extreme halophiles. The proposed project will focus on characterization of newly isolated viruses infecting extreme halophiles, which grow optimally in nearly crystallizing salt concentrations.
