Mathilde Borg Dahl, Stella Brachmann, Andrea Söllinger, Marina Schnell, Laureen Ahlers, Magdalena Wutkowska, Katharina J. Hoff, Neetika Nath, Verena Groß, Haitao Wang, Micha Weil, Marc Piecha, Marc Schaffer, Corinna Jensen, Andreas W. Kuss, Christoph Gall, Erika Wimmer, Thomas Pribasnig, Alexander Tøsdal Tveit, Bjarni D. Sigurdsson, Christa Schleper, Andreas Richter, Tim Urich
{"title":"Quantifying Soil Microbiome Abundance by Metatranscriptomics and Complementary Molecular Techniques—Cross-Validation and Perspectives","authors":"Mathilde Borg Dahl, Stella Brachmann, Andrea Söllinger, Marina Schnell, Laureen Ahlers, Magdalena Wutkowska, Katharina J. Hoff, Neetika Nath, Verena Groß, Haitao Wang, Micha Weil, Marc Piecha, Marc Schaffer, Corinna Jensen, Andreas W. Kuss, Christoph Gall, Erika Wimmer, Thomas Pribasnig, Alexander Tøsdal Tveit, Bjarni D. Sigurdsson, Christa Schleper, Andreas Richter, Tim Urich","doi":"10.1111/1755-0998.14130","DOIUrl":"10.1111/1755-0998.14130","url":null,"abstract":"<p>Linking meta-omics and biogeochemistry approaches in soils has remained challenging. This study evaluates the use of an internal RNA extraction standard and its potential for making quantitative estimates of a given microbial community size (biomass) in soil metatranscriptomics. We evaluate commonly used laboratory protocols for RNA processing, metatranscriptomic sequencing and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Metatranscriptomic profiles from soil samples were generated using two library preparation protocols and prepared in triplicates. RNA extracted from pure cultures of <i>Saccharolobus solfataricus</i> was added to the samples as an internal nucleic acid extraction standard (NAE<sub>std</sub>). RNA reads originating from NAE<sub>std</sub> were identified with a 99.9% accuracy. A remarkable replication consistency between triplicates was seen (average Bray–Curtis dissimilarity 0.03 ± 0.02), in addition to a clear library preparation bias. Nevertheless, the between-sample pattern was not affected by library type. Estimates of 16S rRNA transcript abundance derived from qRT-PCR experiments, NAE<sub>std</sub> and a previously published quantification method of metatranscriptomics (hereafter qMeTra) were compared with microbial biomass carbon (MBC) and nitrogen (MBN) extracts. The derived biomass estimates differed by orders of magnitude. While most estimates were significantly correlated with each other, no correlation was observed between NAE<sub>std</sub> and MBC extracts. We discuss how simultaneous changes in community size and the soils nucleic acid retention strength might hamper accurate biomass estimation. Adding NAE<sub>std</sub> has the potential to shed important light on nucleic acid retention in the substance matrix (e.g., soil) during extraction.</p>","PeriodicalId":211,"journal":{"name":"Molecular Ecology Resources","volume":"25 7","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-0998.14130","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samantha S. Fontaine, Stevie R. Kennedy-Gold, Kurt J. Regester, Jennifer A. Sheridan, Kevin D. Kohl
{"title":"The Impact of Whole-Animal Fluid Preservation on the Observed Gut Microbiome of Vertebrates: Implications for the Use of Museum Specimens in Microbiome Research","authors":"Samantha S. Fontaine, Stevie R. Kennedy-Gold, Kurt J. Regester, Jennifer A. Sheridan, Kevin D. Kohl","doi":"10.1111/1755-0998.14127","DOIUrl":"10.1111/1755-0998.14127","url":null,"abstract":"<p>The vertebrate gut houses diverse microbial communities that provide insights into their host's ecological and evolutionary histories. Nevertheless, microbiome research has not been distributed equally across host taxonomy, geography and timescales. The millions of fluid-preserved specimens stored in natural history museums worldwide represent a potentially untapped resource for microbiome information. However, it is unknown how fluid preservation and long-term storage change the composition and diversity of the original microbial community across a variety of host taxa. Here, we present the largest study to date aimed at addressing this question. Specifically, we identified an optimal method for extracting DNA from preserved samples using commercially available kits. Next, for 11 host species representing four vertebrate classes, we compared the gut microbiomes between animals dissected freshly and those collected simultaneously but subsequently fixed in formalin and stored in 70% ethanol for 1 year, similar to museum conditions. In a secondary analysis in amphibians, we compared our collected samples with those from decades-old historical museum specimens. We found that while fluid preservation altered the community composition and reduced the diversity of the recovered microbiome inventories, host species identity predominated in shaping the gut microbiome, and differences across species and geographic localities were retained after preservation. Historical specimens had microbiomes that were the most different from fresh specimens, suggesting that over time, changes in the microbiome of populations have occurred, or preservation effects have compounded. Considering these findings, we discuss the potential for use of fluid-preserved museum specimens in future microbiome studies.</p>","PeriodicalId":211,"journal":{"name":"Molecular Ecology Resources","volume":"25 7","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-0998.14127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ancient Microbiomes as Mirrored by DNA Extracted From Century-Old Herbarium Plants and Associated Soil","authors":"Gianluca Grasso, Régis Debruyne, Martino Adamo, Olivier Rué, Franck Lejzerowicz, Lucie Bittner, Valeria Bianciotto, Roland Marmeisse","doi":"10.1111/1755-0998.14122","DOIUrl":"10.1111/1755-0998.14122","url":null,"abstract":"<p>Numerous specimens stored in natural history collections have been involuntarily preserved together with their associated microbiomes. We propose exploiting century-old soils occasionally found on the roots of herbarium plants to assess the diversity of ancient soil microbial communities originally associated with these plants. We extracted total DNA and sequenced libraries produced from rhizospheric soils and roots of four plants preserved in herbaria for more than 120 years in order to characterise the preservation and taxonomic diversity that can be recovered in such contexts. Extracted DNA displayed typical features of ancient DNA, with cytosine deamination at the ends of fragments predominantly shorter than 50 bp. When compared to extant microbiomes, herbarium microbial communities clustered with soil communities and were distinct from communities from other environments. Herbarium communities also displayed biodiversity features and assembly rules typical of soil and plant-associated ones. Soil communities were richer than root-associated ones with which they shared most taxa. Regarding community turnover, we detected collection site, soil versus root and plant species effects. Eukaryotic taxa that displayed a higher abundance in roots were mostly plant pathogens that were not identified among soil-enriched ones. Conservation of these biodiversity features and assembly rules in herbarium-associated microbial communities indicates that herbarium-extracted DNA might reflect the composition of the original plant-associated microbial communities and that preservation in herbaria seemingly did not dramatically alter these characteristics. Using this approach, it should be possible to investigate historical soils and herbarium plant roots to explore the diversity and temporal dynamics of soil microbial communities.</p>","PeriodicalId":211,"journal":{"name":"Molecular Ecology Resources","volume":"25 7","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-0998.14122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144136121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Maximising the Potential of Temporal \u0000 \u0000 \u0000 \u0000 N\u0000 \u0000 e\u0000 \u0000 \u0000 \u0000 Estimation in Long-Term Population Monitoring Programmes","authors":"Tin-Yu J. Hui","doi":"10.1111/1755-0998.14125","DOIUrl":"10.1111/1755-0998.14125","url":null,"abstract":"<p>Effective population size (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 </semantics></math>) is indisputably one of the most important parameters in evolutionary biology. It governs the rate of evolution, magnitude of drift, effectiveness of selection, diversity, and many more. It also serves as a key indicator to inform population monitoring programmes, from conservation of endangered species to biocontrol of agricultural pests or disease vectors, and almost everything in between. In applications in which the contemporary <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 </semantics></math> is of interest, temporal <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>F</mi>\u0000 </mrow>\u0000 </semantics></math> is one of the most widely used estimators. It measures the magnitude of drift among genetically neutral loci to estimate the harmonic mean <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 </semantics></math> between two time points. In this issue, Waples et al. (<span>2025</span>) present us a new software “MAXTEMP” to improve the precision of temporal <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>F</mi>\u0000 </mrow>\u0000 </semantics></math> by incorporating additional samples outside of the focal period.</p><p>I was sceptical at first as these seemingly unrelated samples appear to be uninformative, especially after I had revisited Waples (<span>2005</span>) on the time periods at which the temporal <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 </semantics></math> estimates apply. Upon closer inspection, the authors reassured us with an intuitive yet robust argument: consider a population monitoring programme with initially two temporal samples sandwiching the focal period. A direct <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 </semantics></math> estimate is obtained via temporal <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000","PeriodicalId":211,"journal":{"name":"Molecular Ecology Resources","volume":"25 7","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-0998.14125","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144126096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}