bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.05.01.592093

Virome responses to heating of a forest soil suggest that most dsDNA viral particles do not persist at 90°C

Abstract

Many fundamental characteristics of soil viruses remain underexplored, including the effects of high temperatures on viruses and their hosts, as would be encountered under disturbances like wildland fire, prescribed burning, and soil solarization. In this study, we leveraged three data types (DNase-treated viromes, non-DNase-treated viromes, and 16S rRNA gene amplicon sequencing) to measure the responses of soil viral and prokaryotic communities to heating to 30{degrees}C, 60{degrees}C, or 90{degrees}C, in comparison to field and control conditions. We investigated (1) the response of dsDNA viral communities to heating of soils from two horizons (O and A) from the same forest soil profile, (2) the extent to which specific viral taxa could be identified as heat-sensitive or heat-tolerant across replicates and soil horizons, and (3) prokaryotic and virus-host dynamics in response to heating. We found that both viral and prokaryotic communities responded similarly to the treatment variables. Community composition differed most significantly by soil source (O or A horizon). Within both soil horizons, viral and prokaryotic communities clustered into three groups, based on beta-diversity patterns: the ambient community (field, control, and 30{degrees}C samples) and the 60{degrees}C and 90{degrees}C communities. As DNase-treated viromic DNA yields were below detection limits at 90{degrees}C, we infer that most viral capsids were compromised after the 90{degrees}C treatment, indicating a maximum temperature threshold between 60{degrees}C and 90{degrees}C for most viral particles in these soils. We also identified groups of heat-tolerant and heat-sensitive vOTUs across both soil sources. Overall, we found that over 70% of viral populations, like their prokaryotic counterparts, could withstand temperatures as high as 60{degrees}C, with shifts in relative abundance explaining most community compositional differences across heating treatments.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Geonczy, S. E., Hillary, L. S., Santos-Medellin, C., Sorensen, J. W., Fudyma, J. D., Emerson, J. B.. 2024-05-03. Virome responses to heating of a forest soil suggest that most dsDNA viral particles do not persist at 90°C. https://doi.org/10.1101/2024.05.01.592093

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Structural variation in repeat elements is widespread in normal human tissues and in tumorigenesis

Somatic mosaicism contributes to genomic variation, yet postzygotic structural variants remain under-characterized. We performed long- and short-read WGS from multiple individuals (n=47 normal tissues; n=168 samples) and identified mosaic structural variants in all individuals and germ layers, impacting a median 285.2 kb/genome. Nearly half of breakpoints were independently validated, with tissue distributions reflecting both early and late developmental origins. Most mosaic variants were repeat-mediated and 8.3% overlapped functional elements, an enrichment compared to germline variants. To extend these analyses in samples where long-read sequencing is infeasible, we measured repeat alterations from short-read sequencing, recapitulating mosaic tissue-specific differences. We characterized tumor- and tissue- specific variation in repeats across 15 cancer types and found tumor-related repeat variation to be similar in scale to that of normal mosaic variation. Tracking repeat changes in cell-free DNA provided a noninvasive approach for tumor monitoring. Our analyses revealed widespread repeat-driven structural variation in health and disease.

genomics↗

RNA isoform-resolved multiplexed sequencing with bioorthogonal barcoding

RNA isoform dysregulation drives disease pathogenesis and is the target of FDA-approved splice-switching therapeutics. However, multiplexed sequencing methods discard splice junction information because only 3' termini are barcoded and counted. Here, we repurpose acylation and click chemistries to conjugate bioorthogonal barcodes (bobcodes) directly onto multiple internal positions along cellular RNAs. Bobcoded RNAs from multiple samples are pooled for multiplexed cDNA synthesis, during which reverse transcriptase switches from each RNA template onto its tethered bobcode with greater than 99% accuracy in species mixing experiments. Bobcode attachment intervals set cDNA insert sizes without a library fragmentation step, and priming with poly(dT) or random hexamers selects between 3'-end counting and full-length isoform capture. A bioorthogonal barcode-sequencing (BOB-seq v0.1) drug screen identifies transcriptome-wide on- and off-target RNA splicing effects and outperforms existing multiplexing RNA sequencing methods in workflow simplicity, sample-to-sample variability, and barcoding accuracy. Bobcodes add isoform resolution to scalable multiplexed RNA sequencing.

genomics↗

Structural polymorphism and population-variable coding capacity of HERV-K(HML-2) in human pangenomes

Approximately 8% of the human genome is derived from ancient retroviral infections. The most recently integrated of these endogenous retroviruses is the HERV-K(HML-2) clade, whose expression has been associated with cancer, amyotrophic lateral sclerosis, and embryogenesis. Studies of HERV expression, particularly HML-2, have relied predominantly on short-read sequencing. However, the high similarity among HML-2 proviruses prevents many short reads from being assigned uniquely to individual loci. We therefore compared haplotype-resolved long-read genome assemblies from 292 donors to resolve variation in proviral structure and coding capacity. Several loci previously thought to be fixed were structurally polymorphic. Tandem arrays occurred at 13 loci and contained up to six proviral copies in a single array. At 8q11.23, we identified a previously undescribed full-length provirus in one haplotype. All 583 other haplotypes carried a solo-LTR. We found that standard reference genomes failed to represent the coding capacity retained in many individuals, whose proviruses contained intact open reading frames despite disruptive mutations in the reference sequences. Short-read genotypes left 32.5% of the tested donor-variant pairs unresolved at sites associated with viral reading frames. These findings show why HML-2 expression must be interpreted in the context of the structural and coding alleles each individual carries.

genomics↗