Colin Tittes (Groningen / NL), Jeroen G. Nijland (Groningen / NL), Anna M. C. Schoentag (Groningen / NL), Thomas Hackl (Groningen / NL), Nadia di Cianni (Ulm / DE), Anita Marchfelder (Ulm / DE), Tessa E. F. Quax (Groningen / NL)
Like organisms from the other domains of life, archaea are predated upon by viruses. These viruses can have strong effects on host populations and even entire ecosystems. However, the infection mechanisms of archaeal viruses remain poorly understood. While there have been several new discoveries in viruses infecting thermoproteota (formerly crenarchaeota) in recent years, euryarchaeal viruses remain particularly understudied. To improve our understanding of these viruses, model virus-host systems are required.
The halophilic euryarchaeon Haloferax gibbonsii LR2-5 was isolated along with the virus HFTV1 from the hypersaline lake Retba in Senegal [1]. The strain grows well in established media used for other Haloferax species and is highly motile. Its genome has been fully sequenced and annotated. Additionally, it is well suited for light and electron microscopy [2]. Besides the virus it was isolated with, Hfx. gibbonsii LR2-5 has been shown to be infected by nine other viruses [3]. This makes it an attractive model organism for the study of virus-host interactions.
To better research the molecular mechanisms underpinning archaeal virus-host interactions, we have established a genetic system in Hfx. gibbonsii LR2-5 by adapting the well-established system of Hfx. volcanii. This system can be used for plasmid-based protein expression as well as gene deletions. Both expression- and deletion plasmids designed for Hfx. volcanii have been demonstrated to function in Hfx. gibbonsii. This opens up a versatile genetic toolbox for the study of archaeal virus-host interactions.
References
Mizuno, C.M., et al., Novel haloarchaeal viruses from Lake Retba infecting Haloferax and Halorubrum species. Environ Microbiol, 2019. 21(6): p. 2129-2147.Tittes, C., et al., Cellular and Genomic Properties of Haloferax gibbonsii LR2-5, the Host of Euryarchaeal Virus HFTV1. Front Microbiol, 2021. 12: p. 625599.Aguirre Sourrouille, Z., et al., The Viral Susceptibility of the Haloferax Species. Viruses, 2022. 14(6).