Abstract
Hypersaline environments are the source of many viruses infecting different species of halophilic euryarchaea. Information on infection mechanisms of archaeal viruses is scarce, due to the lack of genetically accessible virus–host models. Recently, a new archaeal siphovirus, Haloferax tailed virus 1 (HFTV1), was isolated together with its host belonging to the genus Haloferax, but it is not infectious on the widely used model euryarcheon Haloferax volcanii. To gain more insight into the biology of HFTV1 host strain LR2-5, we studied characteristics that might play a role in its virus susceptibility: growth-dependent motility, surface layer, filamentous surface structures, and cell shape. Its genome sequence showed that LR2-5 is a new strain of Haloferax gibbonsii. LR2-5 lacks obvious viral defense systems, such as CRISPR-Cas, and the composition of its cell surface is different from Hfx. volcanii, which might explain the different viral host range. This work provides first deep insights into the relationship between the host of halovirus HFTV1 and other members of the genus Haloferax. Given the close relationship to the genetically accessible Hfx. volcanii, LR2-5 has high potential as a new model for virus–host studies in euryarchaea.
Highlights
Viruses outnumber their microbial hosts by about a factor of 10 (Bergh et al, 1989; Wommack and Colwell, 2000; Suttle, 2007)
It is possible that the glycans of LR2-5 differ considerably from those of Hfx. volcanii and this difference might be responsible for the differences in virus susceptibility
Further analysis is needed to identify the actual glycans of LR2-5 and to establish if glycosylation is related to infection of Haloferax tailed virus 1 (HFTV1)
Summary
Viruses outnumber their microbial hosts by about a factor of 10 (Bergh et al, 1989; Wommack and Colwell, 2000; Suttle, 2007). Especially those infecting hyperthermophilic crenarchaea, have unique morphologies that are not Properties of Haloferax gibbonsii LR2-5 encountered for viruses infecting bacteria and eukaryotes (Prangishvili et al, 2017; Munson-Mcgee et al, 2018). Mainly infecting euryarchaea, display morphologies shared with some bacterial viruses (bacteriophages), such as head-tail or icosahedral shapes (Pietilä et al, 2014; Prangishvili et al, 2017). The large majority of genes carried by archaeal virus genomes encode proteins of unknown function, and many aspects of the interaction between these viruses and their hosts remain enigmatic (Prangishvili et al, 2017; Krupovic et al, 2018). LR2-5, originate from the saline Lake Retba near Dakar in Senegal (Mizuno et al, 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
