Abstract:Viruses play an essential role in shaping microbial community structures and serve as reservoirs for genetic diversity in many ecosystems. In hyperarid desert environments, where life itself becomes scarce and loses diversity, the interactions between viruses and host populations have remained elusive. Here, we resolved host-virus interactions in the soil metagenomes of the Atacama Desert hyperarid core, one of the harshest terrestrial environments on Earth. We show dispersal of diverse and abundant viruses th… Show more
“…Ralstonia phages detected in Arctic viromes were shown to transduce genomic information of cold-shock proteins to their hosts (47), a clear asset for microorganisms in polar environments. However, we did not find transduction of beneficial genes, which seems to be common in extreme environments (48).…”
Host-associated phages of the bacterium
Ralstonia
identified in snow samples can be used to track microbial dispersal over thousands of kilometers across the Antarctic continent, which functions as an extraterrestrial analogue because of its harsh environmental conditions. Due to the presence of these bacteria carrying genome-integrated prophages on space-related equipment and the potential for dispersal of host-associated phages demonstrated here, our work has implications for planetary protection, a discipline in astrobiology interested in preventing contamination of celestial bodies with alien biomolecules or forms of life.
“…Ralstonia phages detected in Arctic viromes were shown to transduce genomic information of cold-shock proteins to their hosts (47), a clear asset for microorganisms in polar environments. However, we did not find transduction of beneficial genes, which seems to be common in extreme environments (48).…”
Host-associated phages of the bacterium
Ralstonia
identified in snow samples can be used to track microbial dispersal over thousands of kilometers across the Antarctic continent, which functions as an extraterrestrial analogue because of its harsh environmental conditions. Due to the presence of these bacteria carrying genome-integrated prophages on space-related equipment and the potential for dispersal of host-associated phages demonstrated here, our work has implications for planetary protection, a discipline in astrobiology interested in preventing contamination of celestial bodies with alien biomolecules or forms of life.
“…Ralstonia phages detected in Arctic viromes were shown to transduce genomic information of cold-shock proteins to their hosts (47), a clear asset for microorganisms in polar environments. However, we did not find transduction of beneficial genes, which seems to be common in extreme environments (48).…”
Section: Discussioncontrasting
confidence: 86%
“…Ralstonia phages detected in Arctic viromes were shown to transduce genomic information of coldshock proteins to their hosts (49), which would be an asset for microorganisms in polar environments. Although we did not find cold shock genes on PGFs in this study, transduction of beneficial genes, which is common in extreme environments (50), could theoretically be another reason why Ralstonia hosts do not apply CRISPR defenses against their phages. Some Ralstonia phages occur as non-integrative, episomal forms, e.g., RS603, a hybrid of RSM1/3 infecting the phytopathogen Ralstonia solanacearum (51), whose genome lacks a resolvase domain (Figure 2A), but many mesophilic Ralstonia also occur as lysogens (52).…”
Extreme Antarctic conditions provide one of the closest analogues of extraterrestrial environments. Since air and snow samples especially from polar regions yield DNA amounts in the lower picogram range, binning of prokaryotic genomes is challenging and renders studying the dispersal of biological entities across these environments difficult. Here, we hypothesized that dispersal of host-associated bacteriophages (adsorbed, replicating or prophages) across the Antarctic continent can be tracked via their genetic signatures and benefits our understanding of virus and host dispersal across long distances. Phage genome fragments (PGFs) reconstructed from surface snow metagenomes of three Antarctic stations were assigned to four host genomes, mainly Betaproteobacteria including Ralstonia spp. Betaproteobacteria of this genus have been found in Antarctic snow as well as on space-related equipment. We reconstructed the complete genome of a temperate phage with near-complete alignment to a prophage in the reference genome of Ralstonia pickettii 12D. PGFs from different stations were related to each other at the genus level and matched similar hosts. Metagenomic read mapping and nucleotide polymorphism analysis revealed a wide dispersal of highly identical PGFs, 13 of which appeared in seawater from the Western Antarctic Peninsula with up to 5538 km to the snow sampling stations. Our results suggest that host-associated phages, especially of Ralstonia sp. disperse over long distances despite harsh conditions of the Antarctic continent. Due to the additional identification of 14 phages associated with two R. pickettii draft genomes isolated from space equipment, we conclude implications for the spread of biological contaminants in extraterrestrial settings.ImportanceHost-associated phages of the bacterium Ralstonia identified in snow samples can be used to track microbial dispersal over thousands of kilometers across the Antarctic continent, which functions as an extraterrestrial analogue because of its harsh environmental conditions. Due to presence of this bacterial strain including genome-integrated prophages on space-related equipment, and the here demonstrated potential for dispersal of host-associated phages, our work has implications for Planetary Protection, a discipline in Astrobiology interested in preventing contamination of celestial bodies with alien biomolecules or forms of life.
“…Modern high-throughput sequencing technologies classified as next generation sequencing (NGS) can not only detect very small amounts of microbial DNA, but also deliver results that are closer to the real community structure of microorganisms due to the large sequencing volume and high-throughput of these methods. Hwang et al investigated viral genomes from the Atacama Desert using Illumina HiSeq 2500 to reveal the diversity and ecological impact of viruses inhabiting hyper-arid soils (Hwang et al, 2021). Using the same sequencing platform, Le et al compared the metagenomes of soils from extreme hyper-arid deserts to understand the relation between prokaryotic communities and stress responses in soil systems (Le et al, 2016).…”
Turpan Basin located in the eastern Xinjiang is a typical arid inland basin with extremely scarce water resources and a fragile ecosystem. Prokaryotic communities with unique genetic and physiological modifications can survive and function in such harsh environments, offering diverse microbial resources. However, numerous microbes can enter the viable but non-culturable state because of drought stress in the desert soil. In this work, next generation sequencing (NGS) technology based on DNA nanoball sequencing platform (DNBSEQ-G400) and sequencing-by-synthesis platform (NovaSeq 6000) were applied to analyze the prokaryotic diversity in three hyper-arid Gobi soils from Flaming Mountain, Toksun, and Kumtag. The comparison between two platforms indicated that DNBSEQ-G400 had better repeatability and could better reflect the prokaryotic community of this hyper-arid region. The diversity analysis based on DNBSEQ-G400 identified a total of 36 bacterial phyla, including Pseudomonadota, Bacteroidota, Bacillota, Actinomycetota, Methanobacteriota, Acidobacteriota, Nitrososphaerota, and Planctomycetota. The environmental factors, including soluble salt, available potassium, total nitrogen, and organic matter, were positively correlated with the abundance of most prokaryote. In addition, the prokaryotic community assembly in hyper-arid soil was well described by neutral-based models, indicating that the community assembly was mainly controlled by stochastic processes. Finally, the phylogenetic analysis of Actinomycetota proved that such extremophiles played an important role in the ecosystems they colonize. Overall, our result provides a reference for choosing the appropriate sequencing platform and a perspective for the utilization of soil microbial resources from hyper-arid regions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.