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1.
J Anim Ecol ; 93(5): 606-618, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38414265

RESUMO

Human-induced species declines and extinctions have led to the downsizing of large-herbivore assemblages, with implications for many ecosystem processes. Active reintroduction of extirpated large herbivores or their functional equivalents may help to reverse this trend and restore diverse ecosystems and their processes. However, it is unclear whether resource competition between native and non-native herbivores could threaten restoration initiatives, or to what extent (re)introduced species may influence local vegetation dynamics. To answer these questions, we investigated the diets of a novel South American herbivore assemblage that includes resident native species, reintroduced native species and introduced non-native species. We examined plant composition, diet breadth and the overlap between species to describe the local herbivory profile and the potential for resource competition. Using DNA metabarcoding on faecal samples (n = 465), we analysed the diets of the herbivore assemblage in the Rincón del Socorro rewilding area of Iberá National Park, Argentina. We compared the species richness of faecal samples, the occurrence of plant families/growth forms and the compositional similarity of samples (inter- and intraspecifically). Our results indicate species-level taxonomic partitioning of plant resources by herbivores in this system. Differences in sample richness, composition and diet breadth reflected a diverse range of herbivory strategies, from grazers (capybara) to mixed feeders/browsers (brocket deer, lowland tapir). Differences in diet compositional similarity (Jaccard) revealed strong taxonomic resource partitioning. The two herbivores with the most similar diets (Pampas deer and brocket deer) still differed by more than 80%. Furthermore, all but one species (axis deer) had more similar diet composition intraspecifically than compared to the others. Overall, we found little evidence for resource competition between herbivore species. Instead, recently reintroduced native species and historically introduced non-natives are likely expanding the range of herbivory dynamics in the ecosystem. Further research will be needed to determine the full ecological impacts of these (re)introduced herbivores. In conclusion, we show clear differences in diet breadth and composition among native, reintroduced and non-native herbivore species that may be key to promoting resource partitioning, species coexistence and the restoration of ecological function.


La disminución y extinción de especies ocasionada por el hombre ha llevado a la reducción de tamaño de las comunidades de grandes herbívoros, con implicaciones para muchos procesos ecosistémicos. La reintroducción activa de grandes herbívoros extirpados, o sus equivalentes funcionales, puede ayudar a revertir esta tendencia y restaurar diversos ecosistemas y sus procesos. Sin embargo, no está claro si la competencia por recursos entre herbívoros nativos y no nativos podría amenazar las iniciativas de restauración, o en qué medida las especies (re)introducidas pueden influir la dinámica de la vegetación local. Para responder a estas preguntas, investigamos las dietas de una comunidad de herbívoros sudamericanos que incluye especies nativas, especies nativas reintroducidas y especies no nativas introducidas. Examinamos la composición de plantas, la amplitud de la dieta y la superposición entre especies para describir el perfil herbívoro local y el potencial de competencia por los recursos. Utilizando metabarcoding de ADN en muestras fecales (n = 465), analizamos las dietas de la comunidad de herbívoros en el sitio de rewilding Rincón del Socorro dentro del Parque Nacional Iberá, Argentina. Comparamos la riqueza de especies en las muestras fecales, la ocurrencia de familias de plantas/formas de crecimiento y la similitud en la composición de las muestras (interespecíficamente e intraespecíficamente). Nuestros resultados indican la partición taxonómica a nivel de especie de los recursos vegetales por parte de los herbívoros en este sistema. Las diferencias en la riqueza de las muestras, la composición y la amplitud de las dietas reflejaron una amplia gama de estrategias de herbivoría, desde pastoreadores (capibara) hasta herbívoros mixtos/ramoneadores (corzuela, tapir amazónico). Las diferencias en la similitud de la composición de la dieta (Jaccard) revelaron una fuerte partición taxonómica de los recursos. Los dos herbívoros con las dietas más similares (venado de las pampas y corzuela), aún así diferían en más del 80%. Además, todas las especies menos una (ciervo axis) tenían una composición dietética más similar intraespecíficamente que en comparación con las demás. En general, encontramos poca evidencia de competencia por recursos entre las especies de herbívoros. En cambio, las especies nativas reintroducidas recientemente y las no nativas introducidas históricamente probablemente estén ampliando el rango de dinámica de herbivoría en el ecosistema. Se necesitarán más investigaciones para determinar todos los impactos ecológicos de estos herbívoros (re)introducidos. En conclusión, mostramos diferencias claras en la amplitud y composición de la dieta entre especies de herbívoros nativas, reintroducidas y no nativas que pueden ser clave para promover la partición de recursos, la coexistencia de especies y la restauración de las funciones ecológicas.


Assuntos
Dieta , Fezes , Herbivoria , Espécies Introduzidas , Animais , Argentina , Dieta/veterinária , Plantas
2.
Nucleic Acids Res ; 52(D1): D791-D797, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37953409

RESUMO

UNITE (https://unite.ut.ee) is a web-based database and sequence management environment for molecular identification of eukaryotes. It targets the nuclear ribosomal internal transcribed spacer (ITS) region and offers nearly 10 million such sequences for reference. These are clustered into ∼2.4M species hypotheses (SHs), each assigned a unique digital object identifier (DOI) to promote unambiguous referencing across studies. UNITE users have contributed over 600 000 third-party sequence annotations, which are shared with a range of databases and other community resources. Recent improvements facilitate the detection of cross-kingdom biological associations and the integration of undescribed groups of organisms into everyday biological pursuits. Serving as a digital twin for eukaryotic biodiversity and communities worldwide, the latest release of UNITE offers improved avenues for biodiversity discovery, precise taxonomic communication and integration of biological knowledge across platforms.


Assuntos
Bases de Dados de Ácidos Nucleicos , Fungos , DNA Espaçador Ribossômico , Fungos/genética , Biodiversidade , DNA Fúngico , Filogenia
3.
Mol Ecol Resour ; 24(1): e13840, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37497670

RESUMO

The current biodiversity and climate crises highlight the need for efficient tools to monitor terrestrial ecosystems. Here, we provide evidence for the use of airborne eDNA analyses as a novel method for detecting terrestrial vertebrate communities in nature. Metabarcoding of 143 airborne eDNA samples collected during 3 days in a mixed forest in Denmark yielded 64 bird, mammal, fish and amphibian taxa, of which the detected 57 'wild' taxa represent over a quarter of the around 210 terrestrial vertebrates that occur in the overall area. We provide evidence for the spatial movement and temporal patterns of airborne eDNA and for the influence of weather conditions on vertebrate detections. This study demonstrates airborne eDNA for high-resolution biomonitoring of vertebrates in terrestrial systems and elucidates its potential to guide global nature management and conservation efforts in the ongoing biodiversity crisis.


Assuntos
DNA Ambiental , Ecossistema , Animais , Monitoramento Ambiental/métodos , Código de Barras de DNA Taxonômico/métodos , Vertebrados/genética , Biodiversidade , Mamíferos/genética
4.
J Fungi (Basel) ; 9(9)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37755006

RESUMO

We studied the taxonomy of Pluteus podospileus and similar species using morphological and molecular (nrITS, TEF1-α) data, including a detailed study of the type collections of P. inflatus var. alneus, Pluteus minutissimus f. major, and P. granulatus var. tenellus. Within the P. podospileus complex, we phylogenetically confirmed six species in Europe, five in Asia, and eight in North America. Based on our results, we recognize P. seticeps as a separate species occurring in North America, while P. podospileus is limited to Eurasia. We describe six new species and a new variety: P. absconditus, P. fuscodiscus, P. gausapatus, P. inexpectatus, P. millsii, and P. notabilis and its variety, P. notabilis var. insignis. We elevate Pluteus seticeps var. cystidiosus to species rank as Pluteus cystidiosus. Based on the holotype of P. inflatus var. alneus, collections of P. inflatus identified by Velenovský, and several modern collections, we resurrect the name P. inflatus. Based on molecular analyses of syntypes of Pluteus minutissimus f. major and a holotype of Pluteus granulatus var. tenellus, we synonymize them under P. inflatus. We also increase our knowledge about the morphology and distribution of P. cutefractus.

5.
Ecol Evol ; 12(11): e9445, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36340817

RESUMO

Wetlands are important habitats, often threatened by drainage, eutrophication, and suppression of grazing. In many countries, considerable resources are spent combatting scrub encroachment. Here, we hypothesize that encroachment may benefit biodiversity-especially under eutrophic conditions where asymmetric competition among plants compromises conservation targets. We studied the effects of scrub cover, nutrient levels, and soil moisture on the richness of vascular plants, bryophytes, soil fungi, and microbes in open and overgrown wetlands. We also tested the effect of encroachment, eutrophication, and soil moisture on indicators of conservation value (red-listed species, indicator species, and uniqueness). Plant and bryophyte species richness peaked at low soil fertility, whereas soil fertility promoted soil microbes. Soil fungi responded negatively to increasing soil moisture. Lidar-derived variables reflecting the degree of scrub cover had predominantly positive effects on species richness measures. Conservation value indicators had a negative relationship to soil fertility and a positive to encroachment. For plant indicator species, the negative effect of high nutrient levels was offset by encroachment, supporting our hypothesis of competitive release under shade. The positive effect of soil moisture on indicator species was strong in open habitats only. Nutrient-poor mires and meadows host many rare species and require conservation management by grazing and natural hydrology. On former agricultural lands, where restoration of infertile conditions is unfeasible, we recommend rewilding with opportunities for encroachment toward semi-open willow scrub and swamp forest, with the prospect of high species richness in bryophytes, fungi, and soil microbes and competitive release in the herb layer.

6.
Curr Biol ; 32(3): 701-707.e5, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-34995490

RESUMO

Biodiversity monitoring at the community scale is a critical element of assessing and studying species distributions, ecology, diversity, and movements, and it is key to understanding and tracking environmental and anthropogenic effects on natural ecosystems.1-4 Vertebrates in terrestrial ecosystems are experiencing extinctions and declines in both population numbers and sizes due to increasing threats from human activities and environmental change.5-8 Terrestrial vertebrate monitoring using existing methods is generally costly and laborious, and although environmental DNA (eDNA) is becoming the tool of choice to assess biodiversity, few sample types effectively capture terrestrial vertebrate diversity. We hypothesized that eDNA captured from air could allow straightforward collection and characterization of terrestrial vertebrate communities. We filtered air at three localities in the Copenhagen Zoo: a stable, outside between the outdoor enclosures, and in the Rainforest House. Through metabarcoding of airborne eDNA, we detected 49 vertebrate species spanning 26 orders and 37 families: 30 mammal, 13 bird, 4 fish, 1 amphibian, and 1 reptile species. These spanned animals kept at the zoo, species occurring in the zoo surroundings, and species used as feed in the zoo. The detected species comprise a range of taxonomic orders and families, sizes, behaviors, and abundances. We found shorter distance to the air sampling device and higher animal biomass to increase the probability of detection. We hereby show that airborne eDNA can offer a fundamentally new way of studying and monitoring terrestrial communities.


Assuntos
DNA Ambiental , Animais , Biodiversidade , Código de Barras de DNA Taxonômico/métodos , DNA Ambiental/genética , Ecossistema , Monitoramento Ambiental/métodos , Humanos , Mamíferos/genética , Vertebrados/genética
7.
Ambio ; 51(4): 1022-1033, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34448122

RESUMO

The conversion of natural habitats into farmland has been a leading cause of species loss worldwide. Here, we investigated to what extent less intensive soil disturbance can mitigate this loss. Specifically, we examined whether reduced soil disturbance by tillage in agricultural fields could contribute to soil microbial biodiversity by providing a habitat for species that are limited by conventional tillage. To do so, we studied the diversity of soil biotas from three agricultural practices representing conventional tillage, reduced tillage and no tillage. Study fields were sampled by taking a bulk soil sample at the centre and edge of each field. The soil communities were recorded with environmental DNA metabarcoding using three molecular markers targeting bacteria, fungi and eukaryotes. While these three markers represent the vast majority of biotic variation in the soil, they will inevitably be dominated by the megadiverse microbiota of bacteria, microfungi and protists. We found a significant differentiation in community composition related to the intensity of tillage. Richness was weakly correlated to tillage, and more influenced by whether the sample was taken in the center or the edge of the field. Despite the significant effect of tillage on composition, comparisons with natural ecosystems revealed that all 30 study fields were much more similar in composition to other rotational fields than to more natural habitats, oldfields and leys. Despite a slightly higher similarity to oldfields and semi-natural grasslands, the contribution of no-till soil communities to biodiversity conservation is negligible, and our results indicate that restoration on set aside land may contribute more to conservation.


Assuntos
Microbiota , Solo , Agricultura , Biodiversidade , Microbiologia do Solo
8.
Biol Lett ; 17(3): 20200833, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33784872

RESUMO

Monitoring insects across space and time is challenging, due to their vast taxonomic and functional diversity. This study demonstrates how nets mounted on rooftops of cars (car nets) and DNA metabarcoding can be applied to sample flying insect richness and diversity across large spatial scales within a limited time period. During June 2018, 365 car net samples were collected by 151 volunteers during two daily time intervals on 218 routes in Denmark. Insect bulk samples were processed with a DNA metabarcoding protocol to estimate taxonomic composition, and the results were compared to known flying insect richness and occurrence data. Insect and hoverfly richness and diversity were assessed across biogeographic regions and dominant land cover types. We detected 15 out of 19 flying insect orders present in Denmark, with high proportions of especially Diptera compared to Danish estimates, and lower insect richness and diversity in urbanized areas. We detected 319 species not known for Denmark and 174 species assessed in the Danish Red List. Our results indicate that the methodology can assess the flying insect fauna at large spatial scales to a wide extent, but may be, like other methods, biased towards certain insect orders.


Assuntos
Automóveis , Dípteros , Animais , Biodiversidade , DNA , Código de Barras de DNA Taxonômico , Dípteros/genética , Humanos , Insetos
9.
Microorganisms ; 8(12)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33266327

RESUMO

Here, we describe the taxon hypothesis (TH) paradigm, which covers the construction, identification, and communication of taxa as datasets. Defining taxa as datasets of individuals and their traits will make taxon identification and most importantly communication of taxa precise and reproducible. This will allow datasets with standardized and atomized traits to be used digitally in identification pipelines and communicated through persistent identifiers. Such datasets are particularly useful in the context of formally undescribed or even physically undiscovered species if data such as sequences from samples of environmental DNA (eDNA) are available. Implementing the TH paradigm will to some extent remove the impediment to hastily discover and formally describe all extant species in that the TH paradigm allows discovery and communication of new species and other taxa also in the absence of formal descriptions. The TH datasets can be connected to a taxonomic backbone providing access to the vast information associated with the tree of life. In parallel to the description of the TH paradigm, we demonstrate how it is implemented in the UNITE digital taxon communication system. UNITE TH datasets include rich data on individuals and their rDNA ITS sequences. These datasets are equipped with digital object identifiers (DOI) that serve to fix their identity in our communication. All datasets are also connected to a GBIF taxonomic backbone. Researchers processing their eDNA samples using UNITE datasets will, thus, be able to publish their findings as taxon occurrences in the GBIF data portal. UNITE species hypothesis (species level THs) datasets are increasingly utilized in taxon identification pipelines and even formally undescribed species can be identified and communicated by using UNITE. The TH paradigm seeks to achieve unambiguous, unique, and traceable communication of taxa and their properties at any level of the tree of life. It offers a rapid way to discover and communicate undescribed species in identification pipelines and data portals before they are lost to the sixth mass extinction.

10.
Conserv Biol ; 34(3): 697-710, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31729081

RESUMO

Conservation and management of marine biodiversity depends on biomonitoring of marine habitats, but current approaches are resource-intensive and require different approaches for different organisms. Environmental DNA (eDNA) extracted from water samples is an efficient and versatile approach to detecting aquatic animals. In the ocean, eDNA composition reflects local fauna at fine spatial scales, but little is known about the effectiveness of eDNA-based monitoring of marine communities at larger scales. We investigated the potential of eDNA to characterize and distinguish marine communities at large spatial scales by comparing vertebrate species composition among marine habitats in Qatar, the Arabian Gulf (also known as the Persian Gulf), based on eDNA metabarcoding of seawater samples. We conducted species accumulation analyses to estimate how much of the vertebrate diversity we detected. We obtained eDNA sequences from a diverse assemblage of marine vertebrates, spanning 191 taxa in 73 families. These included rare and endangered species and covered 36% of the bony fish genera previously recorded in the Gulf. Sites of similar habitat type were also similar in eDNA composition. The species accumulation analyses showed that the number of sample replicates was insufficient for some sampling sites but suggested that a few hundred eDNA samples could potentially capture >90% of the marine vertebrate diversity in the study area. Our results confirm that seawater samples contain habitat-characteristic molecular signatures and that eDNA monitoring can efficiently cover vertebrate diversity at scales relevant to national and regional conservation and management.


ADN Ambiental de Vertebrados Tomado del Agua Marina para Realizar Biomonitoreos de los Hábitats Marinos Resumen La conservación y el manejo de la biodiversidad marina depende del biomonitoreo de los hábitats marinos, pero las estrategias actuales requieren de muchos recursos y de diferentes estrategias para diferentes organismos. El ADN ambiental (ADNa) extraído de muestras de agua es una estrategia eficiente y versátil para detectar animales acuáticos. En el océano, la composición del ADNa refleja la fauna local a escalas espaciales finas, pero se sabe poco sobre la efectividad del monitoreo basado en el ADNa de las comunidades marinas a grandes escalas. Investigamos el potencial del ADNa para caracterizar y distinguir las comunidades marinas a escalas espaciales grandes mediante una comparación de la composición de especies de vertebrados entre los hábitats marinos de Qatar, en el Golfo Arábigo (también conocido como el Golfo Persa), con base en el meta-código de barras del ADNa extraído de muestras de agua de mar. Realizamos análisis de acumulación de especies para estimar cuánta de la diversidad de vertebrados logramos detectar. Obtuvimos secuencias de ADNa de diversos ensamblajes de vertebrados marinos, los cuales abarcaron 191 taxones de 73 familias. Estos taxones incluyeron a especies raras y en peligro de extinción y cubrieron el 36% de los géneros de peces óseos previamente registrados en el golfo. Los sitios con tipos similares de hábitat también fueron similares en cuanto a la composición del ADNa. Los análisis de acumulación de especies mostraron que el número de réplicas de muestras fue insuficiente para algunos sitios de muestreo, pero sugieren que unos cientos de muestras de ADNa podrían capturar potencialmente >90% de la diversidad de vertebrados marinos en el área de estudio. Nuestros resultados confirman que las muestras de agua marina contienen firmas moleculares características del hábitat y que el monitoreo de ADNa puede cubrir eficientemente la diversidad de vertebrados a escalas relevantes para la conservación y el manejo nacional y regional.


Assuntos
Monitoramento Biológico , DNA Ambiental , Animais , Biodiversidade , Conservação dos Recursos Naturais , Código de Barras de DNA Taxonômico , Ecossistema , Monitoramento Ambiental , Água do Mar , Vertebrados/genética
11.
PLoS One ; 14(7): e0202844, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31283764

RESUMO

Environmental DNA (eDNA) is increasingly applied in ecological studies, including studies with the primary purpose of criminal investigation, in which eDNA from soil can be used to pair samples or reveal sample provenance. We collected soil eDNA samples as part of a large national biodiversity research project across 130 sites in Denmark. We investigated the potential for soil eDNA metabarcoding in predicting provenance in terms of environmental conditions, habitat type and geographic regions. We used linear regression for predicting environmental gradients of light, soil moisture, pH and nutrient status (represented by Ellenberg Indicator Values, EIVs) and Quadratic Discriminant Analysis (QDA) to predict habitat type and geographic region. eDNA data performed relatively well as a predictor of environmental gradients (R2 > 0.81). Its ability to discriminate between habitat types was variable, with high accuracy for certain forest types and low accuracy for heathland, which was poorly predicted. Geographic region was also less accurately predicted by eDNA. We demonstrated the application of provenance prediction in forensic science by evaluating and discussing two mock crime scenes. Here, we listed the plant species from annotated sequences, which can further aid in identifying the likely habitat or, in case of rare species, a geographic region. Predictions of environmental gradients and habitat types together give an overall accurate description of a crime scene, but care should be taken when interpreting annotated sequences, e.g. due to erroneous assignments in GenBank. Our approach demonstrates that important habitat properties can be derived from soil eDNA, and exemplifies a range of potential applications of eDNA in forensic ecology.


Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico , Monitoramento Ambiental/métodos , Solo/química , Dinamarca , Ecologia , Florestas
12.
FEMS Microbiol Ecol ; 95(3)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30715290

RESUMO

Most plants form symbiotic associations with arbuscular mycorrhizal fungi (AMF). AMF increase the uptake of plant nutrients by extending their extra-radical mycelium (ERM) in the soil where other groups of microorganisms may suppress the activity of the ERM. However, little is known about such suppression in natural soils. This work aimed to investigate the incidence of AMF suppression among soils sampled from highly variable natural ecosystems, and used 33P uptake by the ERM to evaluate AMF activity. A second aim was to identify factors behind the observed AMF-suppression. We found that AMF-suppressiveness varied markedly among natural soils and occurred more frequently in low pH than in high pH soils. A previous study for cultivated soils revealed a strong biological component of suppressiveness against AMF, and in accordance we found that the composition of both fungal and bacterial communities differed significantly between AMF-suppressive and non-suppressive natural soils. Acidobacteria, Acidothermus, Xanthomonadaceae, Archaeorhizomyces sp., Mortierella humilis and some Mycena spp. were significantly more abundant in AMF-suppressive soils and may therefore be direct antagonists of AMF. This implies that the functioning of AMF in natural ecosystems is strongly modulated by specific soil microbes.


Assuntos
Micorrizas/fisiologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ecossistema , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Interações Microbianas , Microbiota/genética , Micélio/metabolismo , Micélio/fisiologia , Micorrizas/metabolismo , Fósforo/metabolismo , Solo/química
13.
Nat Commun ; 8(1): 1188, 2017 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084957

RESUMO

DNA metabarcoding is promising for cost-effective biodiversity monitoring, but reliable diversity estimates are difficult to achieve and validate. Here we present and validate a method, called LULU, for removing erroneous molecular operational taxonomic units (OTUs) from community data derived by high-throughput sequencing of amplified marker genes. LULU identifies errors by combining sequence similarity and co-occurrence patterns. To validate the LULU method, we use a unique data set of high quality survey data of vascular plants paired with plant ITS2 metabarcoding data of DNA extracted from soil from 130 sites in Denmark spanning major environmental gradients. OTU tables are produced with several different OTU definition algorithms and subsequently curated with LULU, and validated against field survey data. LULU curation consistently improves α-diversity estimates and other biodiversity metrics, and does not require a sequence reference database; thus, it represents a promising method for reliable biodiversity estimation.


Assuntos
Algoritmos , Biodiversidade , Código de Barras de DNA Taxonômico/métodos , DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise por Conglomerados , DNA de Plantas/genética , DNA Espaçador Ribossômico/genética , Plantas/genética , Reprodutibilidade dos Testes
14.
New Phytol ; 212(4): 1072-1082, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27659274

RESUMO

Woody plants host diverse communities of associated organisms, including wood-inhabiting fungi. In this group, host effects on species richness and interaction network structure are not well understood, especially not at large geographical scales. We investigated ecological, historical and evolutionary determinants of fungal species richness and network modularity, that is, subcommunity structure, across woody hosts in Denmark, using a citizen science data set comprising > 80 000 records of > 1000 fungal species on 91 genera of woody plants. Fungal species richness was positively related to host size, wood pH, and the number of species in the host genus, with limited influence of host frequency and host history, that is, time since host establishment in the area. Modularity patterns were unaffected by host history, but largely reflected host phylogeny. Notably, fungal communities differed substantially between angiosperm and gymnosperm hosts. Host traits and evolutionary history appear to be more important than host frequency and recent history in structuring interactions between hosts and wood-inhabiting fungi. High wood acidity appears to act as a stress factor reducing fungal species richness, while large host size, providing increased niche diversity, enhances it. In some fungal groups that are known to interact with live host cells in the establishment phase, host selectivity is common, causing a modular community structure.


Assuntos
Evolução Biológica , Ecossistema , Fungos/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Madeira/microbiologia , Carpóforos/fisiologia , Filogenia , Especificidade da Espécie
15.
FEMS Microbiol Ecol ; 92(4): fiw045, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26929438

RESUMO

Different distance-based threshold selection approaches were used to assess and compare use of the internal transcribed spacer (ITS) region to distinguish among 901 Cortinarius species represented by >3000 collections. Sources of error associated with genetic markers and selection approaches were explored and evaluated using MOTUs from genus and lineage based-alignments. Our study indicates that 1%-2% more species can be distinguished by using the full-length ITS barcode as compared to either the ITS1 or ITS2 regions alone. Optimal threshold values for different picking approaches and genetic marker lengths inferred from a subset of species containing major lineages ranged from 97.0% to 99.5% sequence similarity using clustering optimization and UNITE SH, and from 1% to 2% sequence dissimilarity with CROP. Errors for the optimal cutoff ranged from 0% to 70%, and these can be reduced to a maximum of 22% when excluding species lacking a barcode gap. A threshold value of 99% is suitable for distinguishing species in the majority of lineages in the genus using the entire ITS region but only 90% of the species could be identified using just the ITS1 or ITS2 region. Prior identification of species, lacking barcode gaps and their subsequent separate analyses, maximized the accuracy of threshold approaches.


Assuntos
Cortinarius/classificação , Cortinarius/genética , Código de Barras de DNA Taxonômico/métodos , DNA Intergênico/genética , Micorrizas/genética , Marcadores Genéticos/genética , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Análise de Sequência de DNA
16.
PLoS One ; 10(11): e0141952, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26559957

RESUMO

Rattus norvegicus (R. norvegicus) are ubiquitous and their presence has several effects on the human populations in our urban areas on a global scale. Both historically and presently, this close interaction has facilitated the dissemination of many pathogens to humans, making screening for potentially zoonotic and emerging viruses in rats highly relevant. We have investigated faecal samples from R. norvegicus collected from urban areas using a protocol based on metagenomic enrichment of circular DNA genomes and subsequent sequencing. We found a new type of papillomavirus, with a L1 region 82% identical to that of the known R. norvegicus Papillomavirus 2. Additionally, we found 20 different circular replication associated protein (Rep)-encoding single stranded DNA (CRESS-DNA) virus-like genomes, one of which has homology to the replication-associated gene of Beak and feather disease virus. Papillomaviruses are a group of viruses known for their carcinogenic potential, and although they are known to infect several different vertebrates, they are mainly studied and characterised in humans. CRESS-DNA viruses are found in many different environments and tissue types. Both papillomaviruses and CRESS-DNA viruses are known to have pathogenic potential and screening for novel and known viruses in R. norvegicus could help identify viruses with pathogenic potential.


Assuntos
Vírus de DNA/genética , DNA Circular/genética , DNA de Cadeia Simples/genética , Metagenômica/métodos , Papillomaviridae/genética , Animais , Sequência de Bases , Cidades , Vírus de DNA/isolamento & purificação , DNA Circular/química , DNA Circular/isolamento & purificação , Fezes/química , Fezes/virologia , Humanos , Dados de Sequência Molecular , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Filogenia , Ratos , Análise de Sequência de DNA
17.
Epilepsy Res ; 105(1-2): 229-33, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23306390

RESUMO

Early Onset Absence Epilepsy constitutes an Idiopathic Generalized Epilepsy with absences starting before the age of four years. Mutations in SLC2A1, encoding the glucose transporter, account for approximately 10% of EOAE cases. The role of SLC2A1 mutations in absence epilepsies with a later onset has not been assessed. We found two mutation carriers in 26 EOAE patients, while no mutations were found in 124 probands affected by CAE or JAE.


Assuntos
Epilepsia Tipo Ausência/epidemiologia , Epilepsia Tipo Ausência/genética , Transportador de Glucose Tipo 1/fisiologia , Mutação/genética , Adolescente , Idade de Início , Sequência de Bases , Estudos de Coortes , Diagnóstico Precoce , Epilepsia Tipo Ausência/diagnóstico , Feminino , Triagem de Portadores Genéticos , Transportador de Glucose Tipo 1/genética , Humanos , Masculino , Dados de Sequência Molecular , Adulto Jovem
18.
Mol Phylogenet Evol ; 44(1): 217-27, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17197201

RESUMO

Cortinarius is the most species rich genus of mushroom forming fungi with an estimated 2000 spp. worldwide. However, species delimitation within the genus is often controversial. This is particularly true in the section Calochroi (incl. section Fulvi), where the number of accepted taxa in Europe ranges between c.60 and c.170 according to different taxonomic schools. Here, we evaluated species delimitation within this taxonomically difficult group of species and estimated their phylogenetic relationships. Species were delimited by phylogenetic inference and by comparison of ITS sequence data in combination with morphological characters. A total of 421 ITS sequences were analyzed, including data from 53 type specimens. The phylogenetic relationships of the identified species were estimated by analyzing ITS data in combination with sequence data from the two largest subunits of RNA polymerase II (RPB1 and RPB2). Seventy-nine species were identified, which are believed to constitute the bulk of the diversity of this group in Europe. The delimitation of species based on ITS sequences is more consistent with a conservative morphological species concept for most groups. ITS sequence data from 30 of the 53 types were identical to other taxa, and most of these can be readily treated as synonyms. This emphasizes the importance of critical analysis of collections before describing new taxa. The phylogenetic separation of species was, in general, unambiguous and there is considerable potential for using ITS sequence data as a barcode for the group. A high level of homoplasy and phenotypic plasticity was observed for morphological and ecological characters. Whereas most species and several minor lineages can be recognized by morphological and ecological character states, these same states are poor indicators at higher levels.


Assuntos
Agaricales/genética , Especiação Genética , Filogenia , Agaricales/classificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/efeitos dos fármacos , Europa (Continente) , Dados de Sequência Molecular , RNA Polimerase II/genética , Análise de Sequência de DNA
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