Metabarcoding and Metagenomics

Plants quick to let their flowers fade for protection, show new field experiments and microbiome

Microbes growing on flowers have adverse effects on their fruit yields. This is why plants are quick to shed their flowers, reveals a new study involving both field experiments and plant microbiome analyses.

*The present study looked into the wild ginger in Japan (Alpinia japonica*, *Zingiberaceae). Its flowers open in the morning and wither around sunset, as many one-day flower plants do.*
*Photo by Shoko Sakai.*

Microbes growing on flowers have adverse effects on their yields. This is why plants are quick to shed their flowers, reveals a new study involving both field experiments and plant microbiome analysis.

The findings – made by a joint team of researchers from the Centre for Research on Ecology and Forestry Applications (CREAF, Spain) and Kyoto University (Japan) – are published in the open-access scholarly journal Metabarcoding and Metagenomics.

Scientifically speaking, flowers are a reproductive structure of a plant. Unlike mammals, though, perennial plants develop those de novo every season and only retain them for as long as needed.

While a few earlier studies have already looked into the variation in flower lifespan among species, they were mainly concerned with the tradeoff between plants spending energy on producing and maintaining their flowers, and the benefit they would achieve from retaining their reproductive organs.

*Most flowers complete their role and wither or drop within only several days or even less.*
*Photo by Shoko Sakai.*

Prior to the present study, however, the team found another perspective to look at the phenomenon: why did plants invest their energy – even if the ‘cost’ was minimal – to produce fragile flowers that would wither in a matter of days, rather than investing a bit more of it to produce a lot more durable ones, thereby increasing their reproductive success?

“Interestingly, flower lifespan is negatively correlated with temperature; the hotter the environment where they bloom, the shorter the period a plant retains them. The phenomenon has been known for a long time.
Then, at some point, I came up with the hypothesis that antagonistic microbes, such as bacteria and fungi growing on flowers after the flower bud opens, must be the driver that shortens the lifespan of a flower. I doubted that it was a coincidence that microbes grow faster in higher temperatures,”
comments Shoko Sakai, author of the present study.

Flowers provide various habitats for microbes. They attract pollinators by secreting nectar, which is rich in sugars, and often contains other nutrients, such as amino acids and lipids. The stigma is a germination bed for pollen grains connected to a growth chamber for pollen tubes. It maintains humidity and nutrients necessary for pollen tube growth. Not surprisingly, abundance of the microbes increases over time on individual flowers after it opens.

Before jumping to their conclusions, the scientists set out to conduct field experiments to see what microbial communities would appear on flowers if their longevity was prolonged.

To do this, they took microbes from old flowers of wild ginger (Alpinia japonica) – a species found in Japan and blooming in the early summer when the hot and humid weather in the country is ideal for microbial growth. Then, they transferred the microbes to other wild ginger plants, whose flowers had just opened.

In line with their initial hypothesis, the research team noted that the plant produced significantly fewer fruits, yet there were no visible symptoms on the flowers or fruits to suggest a disease. However, an analysis of the plants’ microbiomes revealed the presence of several groups of bacteria that were increasing with time. As these bacteria can also be found on the flower buds of flowers that have not been treated, the bacteria is categorised as “resident” for the plant.

“So far, flower characteristics have mostly been studied in the context of their interactions with pollinators. Recent studies have raised the question whether we have overlooked the roles of microbes in the studies of floral characteristics.
For example, flower volatiles – which are often regarded as a primary pollinator attractant – can also function to suppress antagonistic microbes. The impacts of microbes on plant reproductive ecology may be more deeply embedded in the evolution of angiosperms than we have considered,”
Sakai concludes.

*Flowers have various organs rich in nutrients, and each organ harbours a distinct microbiome. Flower visitors transfer microbes between and within flowers.*
*Photo by Shoko Sakai.*

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Research article:

Jiménez Elvira N, Ushio M, Sakai S (2022) Are microbes growing on flowers evil? Effects of old flower microbes on fruit set in a wild ginger with one-day flowers, Alpinia japonica (Zingiberaceae). Metabarcoding and Metagenomics 6: e84331. https://doi.org/10.3897/mbmg.6.84331

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Simplified method to survey amphibians will aid conservation

Researchers developed a method to determine which amphibians inhabit a specific area. The new technique will resolve some of the issues with conventional methods, such as capture and observational surveys.

Ryukyu Sword Tailed Newt, or Firebellied Newt. *Photo by Neil Dalphin via Creative Commons CC0.*

An international collaborative research group of members from seven institutions has developed a method to determine which amphibians (frogs, newts and salamanders) inhabit a specific area. Their work was published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics (MBMG).

To do so, the scientists amplified and analysed extra-organismal DNA (also known as environmental DNA or eDNA) found in the water. This DNA ends up in the water after being expelled from the amphibian’s body along with mucus and excrement.

The research group included Postdoctoral Researcher Sakata K. Masayuki and Professor Minamoto Toshifumi (Kobe University), Associate Professor Kurabayashi Atsushi (Nagahama Institute of Bio-Science and Technology), Nakamura Masatoshi (IDEA Consultants, Inc.) and Associate Professor Nishikawa Kanto (Kyoto University).

The newly developed technique will resolve some of the issues with conventional methods, such as capture and observational surveys, which require a specialist surveyor who can visually identify species. Conventional surveys are also prone to discrepancies due to environmental factors, such as climate and season.

The researchers hope that the new method will revolutionise species monitoring, as it will enable anyone to easily monitor the amphibians that inhabit an area by collecting water samples.

While monitoring in general is crucial to conserve the natural ecosystems, the importance of surveying amphibians is even more pressing, given the pace of their populations’ decline.

Amongst major obstacles to amphibian monitoring, however, are the facts that they are nocturnal; their young (e.g. tadpoles) and adults live in different habitats; and that specialist knowledge is required to capture individuals and identify their species. These issues make it particularly difficult to accurately survey amphibians in a standardised way, and results of individual efforts often contradict each other.

On the other hand, eDNA analysis techniques have already been established in programmes targeted at monitoring fish species, where they are already commonplace. So, the researchers behind the present study joined forces to contribute towards the development of a similar standardised analysis method for amphibians.

First of all, the researchers designed multiple methods for analysing the eDNA of amphibians and evaluated their performance to identify the most effective method. Next, they conducted parallel monitoring of 122 sites in 10 farmlands across Japan using the developed eDNA analysis along with the conventional methods (i.e. capture surveys using a net and observation surveys).

As a result, the newly developed method was able to detect all three orders of amphibians: Caudata (the newts and salamanders), Anura (the frogs), and Gymnophiona (the caecilians).

Furthermore, this novel eDNA analysis method was able to detect more species across all field study sites than the conventional method-based surveys, indicating its effectiveness.

Research Background

Amphibian biodiversity is continuing to decline worldwide and collecting basic information about their habitats and other aspects via monitoring is vital for conservation efforts. Traditional methods of monitoring amphibians include visual and auditory observations, and capture surveys.

However, amphibians tend to be small in size and many are nocturnal. The success of surveys varies greatly depending on the climate and season, and specialist knowledge is required to identify species. Consequently, it is difficult to monitor a wide area and assess habitats. The last decade has seen the significant development of environmental DNA analysis techniques, which can be used to investigate the distribution of a species by analysing external DNA (environmental DNA) that is released into the environment along with an organism’s excrement, mucus and other bodily fluids.

The fundamentals of this technique involve collecting water from the survey site and analysing the eDNA contained in it to find out which species inhabit the area. In recent years, the technique has gained attention as a supplement for conventional monitoring methods. Standardised methods of analysis have already been established for other species, especially fishes, and diversity monitoring using eDNA is becoming commonplace.

However, eDNA monitoring of amphibians is still at the development stage. One reason for this is that the proposed eDNA analysis method must be suitable for the target species or taxonomic group, and there are still issues with developing and implementing a comprehensive method for detecting amphibians. If such a method could be developed, this would make it possible for monitoring to be conducted even by people who do not have the specialised knowledge to identify species nor surveying experience.

Hopefully, this would be established as a unified standard for large-scale monitoring surveys, such as those on a national scale. This research group’s efforts to develop and evaluate analysis methods will hopefully lay the foundations for eDNA analysis to become a common tool for monitoring amphibians, as well as fish.

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Research article:

Sakata MK, Kawata MU, Kurabayashi A, Kurita T, Nakamura M, Shirako T, Kakehashi R, Nishikawa K, Hossman MY, Nishijima T, Kabamoto J, Miya M, Minamoto T (2022) Development and evaluation of PCR primers for environmental DNA (eDNA) metabarcoding of Amphibia. Metabarcoding and Metagenomics 6: e76534. https://doi.org/10.3897/mbmg.6.76534

Extensive practical guide to DNA-based biodiversity assessment methods published as a ‘living’ document by DNAqua-Net COST Action

Between 2016 and 2021, over 500 researchers collaborated within the DNAqua-Net international network, funded by the European Union’s European Cooperation in Science and Technology programme (COST), with the goal to develop and advance biodiversity assessment methods based on analysis of DNA obtained from the environment (e.g. river water) or from unsorted collections of organisms.

Such innovative methods are a real game changer when it comes to large-scale assessment of biodiversity and ecological monitoring, as collecting environmental samples that are sent to the lab for analysis is much cheaper, faster and non-invasive, compared with capturing and examining live organisms. However, large-scale adoption has been hindered by a lack of standardisation and official guidance.

Recognising the urgent need to scale up ecological monitoring as we respond to the biodiversity and climate crises, the DNAqua-Net team published a guidance document for the implementation of DNA-based biomonitoring tools.

The guide considers four different types of samples: water, sediments, invertebrate collections and diatoms, and two primary analysis types: single species detection via qPCR and similar targeted methods; and assessment of biological communities via DNA metabarcoding. At each stage of the field and laboratory process the guide sets out the scientific consensus, as well as the choices that need to be made and the trade-offs they entail. In particular, the guide considers how the choices may be influenced by common practical constraints such as logistics, time and budget. Available in an Advanced Book format, the guidelines will be updated as the technology continues to evolve.

Leaders of DNAqua-Net are Prof. Dr. Florian Leese of the University of Duisburg-Essen (Germany) and Dr. Agnès Bouchez of the French National Institute for Agriculture, Food, and Environment (INRAE). The core writing team for the present guide book involves Dr. Micaela Hellström (MIX Research AB, Sweden), Dr. Kat Bruce (NatureMetrics Ltd., UK), Dr. Rosetta Blackman (University of Zurich and EAWAG, Switzerland), Dr. Sarah Bourlat (LIB/Museum Koenig, Germany), and Prof. Kristy Deiner (ETH Zurich and SimplexDNA AG, Switzerland).

“Back in 2016 we realised that all around the globe researchers are testing new eDNA methods, developing individual solutions and products. While this is excellent, we need to reach a consensus and provide this consensus to stakeholders from the applied sectors”,
says Florian Leese.

This video was created as part of EU COST Action DNAqua-Net (CA15219) and shows how environmental DNA (eDNA) can be sampled and analysed from aquatic ecosystems. It shows the whole cycle from the start to final results.
Credit: DNAqua-Net

The guide’s lead author Dr. Kat Bruce adds:

“The urgency of addressing the twin biodiversity and climate crises means that we need to accelerate the adoption of new technologies that can provide data and insights at large scales. In doing so, we walk a tricky line to agree on sufficiently standardised methods that can be usefully applied as soon as they add value, while still continuing to develop them further and innovate within the field. It was a daunting task to seek consensus from several hundred scientists working in a fast-moving field, but we found that our technology is based on a strong foundation of knowledge and there was a high level of agreement on the core principles – even if the details vary and different users make different choices depending on their environmental, financial or logistical constraints.”

Looking back on the last four years that culminated in the publication of a “living” research publication, Prof. Dr. Kristy Deiner says:

“The document took many twists and turns through more than ten versions and passionate discussions across many workshops and late night drinks. All in the days when we could linger at conferences without fear of the pandemic weighing on us. As we worked to find consensus, one thing was clear: we had a lot to say and a standard review paper was not going to cut it. With the knowledge and experience gathered across the DNAqua-Net, it made sense to not limit this flow of information, but rather to try and tackle it head on and use it to address the many questions we’ve all struggled with while developing DNA-based biodiversity survey methods.”

Now that the document – or at least its first version – is publicly available, the researchers are already planning for the next steps and challenges.

“The bottom line is we’ve come a long way in the last ten years. We have a buffet of methods for which many produce accurate, reliable and actionable data to the aid of biodiversity monitoring and conservation. While there is still much work to be done, the many unanswered questions are because the uptake is so broad. With this broad uptake comes novel challenges, but also new insights and a diversity of minds with new ideas to address them. As said this is planned to be a living document and we welcome continued inputs no matter how great or small,” says Deiner.

Dr. Micaela Hellström recalls:

“The book evolved over the four years of COST Action DNAqua-Net which made it possible for the many scientists and stakeholders involved to collaborate and exchange knowledge on an unprecedented scale. Our whole team is well aware of the urgent need to monitor biodiversity loss and to provide accurate species distribution information on large scales, to protect the species that are left. This was a strong driving force for all of us involved in the production of this document. We need consensus on how to coherently collect biodiversity data to fully understand changes in nature.”

“It was a great and intense experience to be a part of the five-person core writing team. In the months prior to submitting the document, we spent countless hours, weekends and late nights researching the field, communicating with researchers and stakeholders, and joining vivid Zoom discussions. As a result, the present book provides solid guidance on multiple eDNA monitoring methods that are – or will soon become – available as the field moves forward.”

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The DNAqua-Net team invites fellow researchers and practitioners to provide their feedback and personal contributions using the contacts below.

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Original source:

Bruce K, Blackman R, Bourlat SJ, Hellström AM, Bakker J, Bista I, Bohmann K, Bouchez A, Brys R, Clark K, Elbrecht V, Fazi S, Fonseca V, Hänfling B, Leese F, Mächler E, Mahon AR, Meissner K, Panksep K, Pawlowski J, Schmidt Yáñez P, Seymour M, Thalinger B, Valentini A, Woodcock P, Traugott M, Vasselon V, Deiner K (2021) A practical guide to DNA-based methods for biodiversity assessment. Advanced Books. https://doi.org/10.3897/ab.e68634

One water bucket to find them all: Detecting fish, mammals, and birds from a single sample

Revolutionary environmental DNA analysis holds great potential for the future of biodiversity monitoring, concludes a new study.

Revolutionary environmental DNA analysis holds great potential for the future of biodiversity monitoring, concludes a new study

Collection of water samples for eDNA metabarcoding bioassessment.
*Photo by Till-Hendrik Macher.*

In times of exacerbating biodiversity loss, reliable data on species occurrence are essential, in order for prompt and adequate conservation actions to be initiated. This is especially true for freshwater ecosystems, which are particularly vulnerable and threatened by anthropogenic impacts. Their ecological status has already been highlighted as a top priority by multiple national and international directives, such as the European Water Framework Directive.

However, traditional monitoring methods, such as electrofishing, trapping methods, or observation-based assessments, which are the current status-quo in fish monitoring, are often time- and cost-consuming. As a result, over the last decade, scientists progressively agree that we need a more comprehensive and holistic method to assess freshwater biodiversity.

Meanwhile, recent studies have continuously been demonstrating that eDNA metabarcoding analyses, where DNA traces found in the water are used to identify what organisms live there, is an efficient method to capture aquatic biodiversity in a fast, reliable, non-invasive and relatively low-cost manner. In such metabarcoding studies, scientists sample, collect and sequence DNA, so that they can compare it with existing databases and identify the source organisms.

Furthermore, as eDNA metabarcoding assessments use samples from water, often streams, located at the lowest point, one such sample usually contains not only traces of specimens that come into direct contact with water, for example, by swimming or drinking, but also collects traces of terrestrial species indirectly via rainfalls, snowmelt, groundwaters etc.

In standard fish eDNA metabarcoding assessments, these ‘bycatch data’ are typically left aside. Yet, from a viewpoint of a more holistic biodiversity monitoring, they hold immense potential to also detect the presence of terrestrial and semi-terrestrial species in the catchment.

In their new study, reported in the open-access scholarly journal Metabarcoding and Metagenomics, German researchers from the University of Duisburg-Essen and the German Environment Agency successfully detected an astonishing quantity of the local mammals and birds native to the Saxony-Anhalt state by collecting as much as 18 litres of water from across a two-kilometre stretch along the river Mulde.

After water filtration the eDNA filter is preserved in ethanol until further processing in the lab.
*Photo by Till-Hendrik Macher.*

In fact, it took only one day for the team, led by Till-Hendrik Macher, PhD student in the German Federal Environmental Agency-funded GeDNA project, to collect the samples. Using metabarcoding to analyse the DNA from the samples, the researchers identified as much as 50% of the fishes, 22% of the mammal species, and 7.4% of the breeding bird species in the region.

However, the team also concluded that while it would normally take only 10 litres of water to assess the aquatic and semi-terrestrial fauna, terrestrial species required significantly more sampling.

Unlocking data from the increasingly available fish eDNA metabarcoding information enables synergies among terrestrial and aquatic biodiversity monitoring programs, adding further important information on species diversity in space and time.

“We thus encourage to exploit fish eDNA metabarcoding biodiversity monitoring data to inform other conservation programs,”
says lead author Till-Hendrik Macher.

“For that purpose, however, it is essential that eDNA data is jointly stored and accessible for different biodiversity monitoring and biodiversity assessment campaigns, either at state, federal, or international level,”
concludes Florian Leese, who coordinates the project.

Original source:

Macher T-H, Schütz R, Arle J, Beermann AJ, Koschorreck J, Leese F (2021) Beyond fish eDNA metabarcoding: Field replicates disproportionately improve the detection of stream associated vertebrate species. Metabarcoding and Metagenomics 5: e66557. https://doi.org/10.3897/mbmg.5.66557

Scientists took a rare chance to prove we can quantify biodiversity by ‘testing the water’

Recent study conducted at a UK fishery farm provides new evidence that DNA from water samples can accurately determine fish abundance and biomass

Organisms excrete DNA in their surroundings through metabolic waste, sloughed skin cells or gametes, and this genetic material is referred to as environmental DNA (eDNA).

As eDNA can be collected directly from water, soil or air, and analysed using molecular tools with no need to capture the organisms themselves, this genetic information can be used to report biodiversity in bulk. For instance, the presence of many fish species can be identified simultaneously by sampling and sequencing eDNA from water, while avoiding harmful capture methods, such as netting, trapping or electrofishing, currently used for fish monitoring.

While the eDNA approach has already been applied in a number of studies concerning fish diversity in different types of aquatic habitats: rivers, lakes and marine systems, its efficiency in quantifying species abundance (number of individuals per species) is yet to be determined. Even though previous studies, conducted in controlled aquatic systems, such as aquaria, experimental tanks and artificial ponds, have reported positive correlation between the DNA quantity found in the water and the species abundance, it remains unclear how the results would fare in natural environments.

However, a research team from the University of Hull together with the Environment Agency (United Kingdom), took the rare opportunity to use an invasive species eradication programme carried out in a UK fishery farm as the ultimate case study to evaluate the success rate of eDNA sampling in identifying species abundance in natural aquatic habitats. Their findings were published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics.

“Investigating the quantitative power of eDNA in natural aquatic habitats is difficult, as there is no way to ascertain the real species abundance and biomass (weight) in aquatic systems, unless catching all target organisms out of water and counting/measuring them all,”
explains Cristina Di Muri, PhD student at the University of Hull.

Drained pond after fish translocation.
Photo by Dr. Watson H.V.

During the eradication, the original fish ponds were drained and all fish, except the problematic invasive species: the topmouth gudgeon, were placed in a new pond, while the original ponds were treated with a piscicide to remove the invasive fish. After the eradication, the fish were returned to their original ponds. In the meantime, all individuals were counted, identified and weighed from experts, allowing for the precise estimation of fish abundance and biomass.

“We then carried out our water sampling and ran genetic analysis to assess the diversity and abundance of fish genetic sequences, and compared the results with the manually collected data. We found strong positive correlations between the amount of fish eDNA and the actual fish species biomass and abundance, demonstrating the existence of a strong association between the amount of fish DNA sequences in water and the actual fish abundance in natural aquatic environments,”
reports Di Muri.

Environmental DNA sampling using water collection bottles
Photo by Dr. Peirson G.

The scientists successfully identified all fish species in the ponds: from the most abundant (i.e. 293 carps of 852 kg total weight) to the least abundant ones (i.e. one chub of 0.7 kg), indicating the high accuracy of the non-invasive approach.

“Furthermore, we used different methods of eDNA capture and eDNA storage, and found that results of the genetic analysis were comparable across different eDNA approaches. This consistency allows for a certain flexibility of eDNA protocols, which is fundamental to maintain results comparable across studies and, at the same time, choose the most suitable strategy, based on location surveyed or resources available,”
elaborates Di Muri.

“The opportunity of using eDNA analysis to accurately assess species diversity and abundance in natural environments will drive a step change in future species monitoring programmes, as this non-invasive, flexible tool is adaptable to all aquatic environments and it allows quantitative biodiversity surveillance without hampering the organisms’ welfare.”

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Original publication:

Di Muri C, Lawson Handley L, Bean CW, Li J, Peirson G, Sellers GS, Walsh K, Watson HV, Winfield IJ, Hänfling B (2020) Read counts from environmental DNA (eDNA) metabarcoding reflect fish abundance and biomass in drained ponds. Metabarcoding and Metagenomics 4: e56959. https://doi.org/10.3897/mbmg.4.56959

DNA metabarcoding detects ecological stress within freshwater species

Metabarcoding allows scientists to extract DNA from the environment, in order to rapidly detect species inhabiting a particular habitat. While the method is a great tool that facilitates conservation activities, few studies have looked into its applicability in monitoring species’ populations and their genetic diversity, which could actually be critical to assess negative trends early on. The potential of the method is confirmed in a new study, published in the peer-reviewed scholarly journal Metabarcoding & Metagenomics.

In a new study, German scientists confirm that responses below species level can be inferred with DNA metabarcoding

Metabarcoding allows scientists to extract DNA from the environment (known as environmental DNA or eDNA), for example, river water or, as in the case of the study by the team from the University of Duisburg-Essen (Essen, Germany) within the German Barcode of Life project (GBOL II): Vera Zizka, Dr Martina Weiss and Prof Florian Leese, from individuals in bulk samples. Thus, they are able to detect what species inhabit a particular habitat.

However, while the method has already been known to be of great use in getting an approximate picture of local fauna, hence facilitating conservation prioritisation, few studies have looked into its applicability to infer responses below species level. That is, how the populations of a particular species fare in the environment of interest, also referred to as intraspecific diversity. Meanwhile, the latter could actually be a lot more efficient in ecosystem monitoring and, consequently, biodiversity loss mitigation.

The potential of the method is confirmed in a new study, published in the peer-reviewed scholarly journal Metabarcoding & Metagenomics. To do so, the researchers surveyed the populations of macroinvertebrate species (macrozoobenthos) in three German rivers: Emscher, Ennepe and Sieg, where each is subject to a different level of ecological disturbance. They were looking specifically at species reported at all of the survey sites by studying the number of different haplotypes (a set of DNA variations usually inherited together from the maternal parent) in each sample. The researchers point out that macrozoobenthos play a key role in freshwater ecosystem functionality and include a wide range of taxonomic groups with often narrow and specific demands with respect to habitat conditions.

“As the most basal level of biodiversity, genetic diversity within species is typically the first to decrease, and the last to regenerate, after stressor’s impact. It consequently provides a proxy for environmental impacts on communities long before, or even if never visible on species diversity level,”
explain the scientists.

Emscher is an urban stream in the Ruhr Metropolitan Area that has been used as an open sewage channel for the past hundred years, and is considered to be a very disturbed environment. Ennepe – regarded as moderately stressed – runs through both rural and urban sites, including ones with sewage treatment plant inflow. Meanwhile, Sieg is considered as a stable, near-natural river system with a good ecological and chemical status.

As a result, despite their original assumption that Sieg would support the most prominent diversity within populations of species sensitive to organic pollution, such as mayflies, stoneflies and caddisflies, the scientists reported no significant difference to the medium stressed river Ennepe. This was also true for overall biodiversity. On the other hand, the team discovered higher intraspecific diversity for species resilient to ecological disturbance like small worms and specialised crustaceans in the heavily disturbed Emscher. The latter phenomenon may be explained with low competition pressure for these species, their ability to use organic compounds as resources and, consequently, increased population growth.

“[T]his pioneer study shows that the extraction of intraspecific genetic variation, so-called ‘haplotypes’ from DNA metabarcoding datasets is a promising source of information to assess intraspecific diversity changes in response to environmental impacts for a whole metacommunity simultaneously,”
conclude the scientists.

However, the researchers also note limitations of their study, including the exclusion of specialist species that only occured at single sites. They prompt future studies to also carefully control for the individual number of specimens per species to quantify genetic diversity change specifically.

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Original source:

Zizka VMA, Weiss M, Leese F (2020) Can metabarcoding resolve intraspecific genetic diversity changes to environmental stressors? A test case using river macrozoobenthos. Metabarcoding and Metagenomics 4: e51925. https://doi.org/10.3897/mbmg.4.51925

Pan-European sampling campaign sheds light on the massive diversity of freshwater plankton

In a major pan-European study, a research team from Germany have successfully extracted environmental DNA (eDNA) from as many as 218 lakes to refute a long-year belief that vital microorganisms do not differ significantly between freshwater bodies and geographic regions the way plants and animals do.

Their new-age approach to biodiversity studies resulted in the largest freshwater dataset along with a study published in the open access journal Metabarcoding and Metagenomics.

Surface freshwaters are of critical importance for terrestrial life and, in particular, human life and welfare. However, these vital ecosystems are severely understudied, as compared to terrestrial or oceanic biomes, and so are the microbial organisms living in them.

On the other hand, it is these invisible to the naked eye creatures, called protists, that are responsible for keeping our ecosystems running. Their diversity and their high metabolic rates maintain ecosystem stability. In fact, microbes are the major source of the worlds oxygen.

In 2012, the team of Prof. Jens Boenigk, University of Duisburg-Essen, undertook the sampling campaign to study the distribution pattern of microbial organisms on a continental scale and the impact of Europe’s climatic history on their present-day whereabouts.

They sampled freshwater lakes and ponds from sites in Norway, Sweden, Germany, Poland, the Czech Republic, Slovakia, Hungary, Romania, Austria, Italy, France, Spain and Switzerland. Site selection focused on the European orogens, specifically the Alps, the Pyrenees, the Apennine, the High Tatras, the southern Scandinavian mountains and the connecting flatlands.

Thanks to the excellent collaboration both within the team and with a number of scientific institutions across Europe, which gave their support as access points for re-stocking sampling equipment and immediate sample preservation, the campaign delivered groundbreaking results illuminating the hidden diversity of the microbial biosphere.

The scientists reported that plankton diversity was highly partitioned between lakes which bear distinct biological fingerprints. In particular, high mountain ranges imprinted the microbial communities on both regional and continental scale. Ecological factors, such as temperature and nutrient concentrations, are well accepted factors structuring plankton communities.

Beyond the high plankton diversity and the associated highly specific community composition in distinct lakes, the plankton community composition revealed signals of the past, i.e. since the last glaciation some 12,000 years ago.

While this expedition yielded many new scientific findings, the scientists note that these are only the first results of this continental survey.

“We are well aware that we have only just begun our exploration of the hidden diversity of plankton diversity,” they conclude.

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Original source:

Boenigk J, Wodniok S, Bock C, Beisser D, Hempel C, Grossmann L, Lange A, Jensen M (2018) Geographic distance and mountain ranges structure freshwater protist communities on a European scale. Metabarcoding and Metagenomics 2: e21519. https://doi.org/10.3897/mbmg.2.21519

New open-access journal Metabarcoding & Metagenomics joins the lines of publisher Pensoft

The new innovative academic journal makes use of the one-of-a-kind publishing platform ARPHA and its collaborative writing tool via the ARPHA-XML workflow

A new innovative open-access academic journal Metabarcoding and Metagenomics (MBMG) is launched to welcome novel papers from both basic and applied aspects.

Focusing on genetic approaches to study biodiversity across all ecosystems, MBMG covers a considerably large scope of research including environmental, microbial and applied metabarcoding and metagenomics (especially DNA-based bioassessment and -monitoring, quarantine, nature conservation, species invasions, eDNA surveillance), as well as associated topics, such as molecular ecology, DNA-based species delimitation and identification, and other emerging related fields. Submissions of bioinformatic approaches to MBMG (algorithms, software) are also encouraged.

Featuring novel article formats and data publishing workflows, MBMG is to reflect the rapid growth in the use of metabarcoding and metagenomics in life and environmental sciences.

Issued via ARPHA – the first ever publishing platform to support manuscripts all the way from authoring to peer review to publication and dissemination, designed by the academic publisher and technology provider Pensoft, the new journal is to host a wide range of outcomes from across the research cycle, including data, models, methods, workflows, software, perspectives, opinions, implementation strategies, as well as conventional research articles.

While the above-mentioned publication types are already available in other journals published on the ARPHA platform, such as Research Ideas and Outcomes (RIO), Biodiversity Data Journal and One Ecosystem, MBMG provides five extra domain-specific article types, namely: Emerging Technique, Applied Study, DNA Barcode Release, Primer Validation and Probe Validation.

The journal’s articles are to be available in three formats (PDF, XML, HTML) and full of semantic enhancements for better human- and machine-readability and discoverability. The XML-based workflow also ensures that content and data are available for extraction, indexing and re-use immediately after publication.

With Pensoft standing for transparent, reproducible and open science, the authors at MBMG are strongly encouraged to make all data publicly available either within the publication itself, or to link to external repositories. In their turn, the peer reviewers are also suggested to provide public access to their reviews and identities.

In time for the launch, MBMG has already gathered a team of experienced and renowned scientists from across the globe together on its editorial and advisory board.

“I am pleased to introduce the Metabarcoding and Metagenomics journal to the family of Pensoft,” says Prof. Lyubomir Penev, Founder and Managing Director at Pensoft. “With its exhaustive scope and advanced services and concept, I believe it fills fantastically a niche in our strong portfolio of mostly biodiversity- and ecology-themed journals.”

“Metabarcoding and metagenomics approaches are rapidly progressing and revolutionise research and its application alike,” Chief Editor Prof. Florian Leese states. “With the MBMG journal we provide an ideal platform to respond to this rapidly growing field, nucleate the emerging knowledge and stimulate further development.”

The first batch of research papers published in MBMG are now available on their new website.

“MBMG not only complements the range of journals in the field of molecular environmental life sciences, but also stands out as a novel outlet providing several unique features designed to help researchers to prepare for, and professionally deal with, the massive “deluge” of data,” reads the Editorial.

To celebrate the launch, MBMG starts with a tempting offer to potential authors: publishing will be completely free of charge during the beginning stages of the journal.

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