| 1. |
- Bourlat, Sarah, et al.
(författare)
-
Preparation of Amplicon Libraries for Metabarcoding of Marine Eukaryotes Using Illumina MiSeq: The Dual-PCR Method
- 2016
-
Ingår i: Marine Genomics: Methods and Protocols. - New York : Springer. - 9781493937721 ; , s. 197-207
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This protocol details the preparation of multiplexed amplicon libraries for metabarcoding (amplicon-based) studies of microscopic marine eukaryotes. Metabarcoding studies, based on the amplification of a taxonomically informative marker from a collection of organisms or an environmental sample, can be performed to analyze biodiversity patterns or predator–prey interactions. For Metazoa, we use the mitochondrial cytochrome oxidase 1 (CO1) or the small ribosomal subunit (SSU) markers. Here, we describe a strategy for the preparation of multiplexed Illumina MiSeq libraries using a dual-PCR approach for the addition of index and adaptor sequences.
|
|
| 2. |
- Haenel, Quiterie, et al.
(författare)
-
NGS-based biodiversity and community structure analysis of meiofaunal eukaryotes in shell sand from Hållö island, Smögen, and soft mud from Gullmarn Fjord, Sweden
- 2017
-
Ingår i: Biodiversity Data Journal. - : Oleksandr Holovachov. - 1314-2828 .- 1314-2836. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- © Haenel Q et al. Aim: The aim of this study was to assess the biodiversity and community structure of Swedish meiofaunal eukaryotes using metabarcoding. To validate the reliability of the metabarcoding approach, we compare the taxonomic resolution obtained using the mitochondrial cytochrome oxidase 1 (COI) 'mini-barcode' and nuclear 18S small ribosomal subunit (18S) V1-V2 region, with traditional morphology-based identification of Xenacoelomorpha and Nematoda. Location: 30 samples were analysed from two ecologically distinct locations along the west coast of Sweden. 18 replicate samples of coarse shell sand were collected along the northeastern side of Hållö island near Smögen, while 12 replicate samples of soft mud were collected in the Gullmarn Fjord near Lysekil.
|
|
| 3. |
- Holovachov, Oleksandr, et al.
(författare)
-
Taxonomy assignment approach determines the efficiency of identification of OTUs in marine nematodes
- 2017
-
Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- © 2017 The Authors. Precision and reliability of barcode-based biodiversity assessment can be affected at several steps during acquisition and analysis of data. Identification of operational taxonomic units (OTUs) is one of the crucial steps in the process and can be accomplished using several different approaches, namely, alignment-based, probabilistic, tree-based and phylogenybased. The number of identified sequences in the reference databases affects the precision of identification. This paper compares the identification of marine nematode OTUs using alignment-based, tree-based and phylogeny-based approaches. Because the nematode reference dataset is limited in its taxonomic scope, OTUs can only be assigned to higher taxonomic categories, families. The phylogeny-based approach using the evolutionary placement algorithm provided the largest number of positively assigned OTUs and was least affected by erroneous sequences and limitations of reference data, compared to alignment-based and tree-based approaches.
|
|
| 4. |
- Holovachov, Oleksandr
(författare)
-
The choice of taxonomy assignment approach has strong impact on the efficiency of identification of OTUs in marine nematodes
- 2017
-
Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Precision and reliability of barcode-based biodiversity assessment can be affected at several steps during acquisition and analysis of data. Identification of operational taxonomic units (OTUs) is one of the crucial steps in the process and can be accomplished using several different approaches, namely, alignment-based, probabilistic, tree-based and phylogeny-based. The number of identified sequences in the reference databases affects the precision of identification. This paper compares the identification of marine nematode OTUs using alignment-based, tree-based and phylogeny-based approaches. Because the nematode reference dataset is limited in its taxonomic scope, OTUs can only be assigned to higher taxonomic categories, families. The phylogeny-based approach using the evolutionary placement algorithm provided the largest number of positively assigned OTUs and was least affected by erroneous sequences and limitations of reference data, compared to alignment-based and tree-based approaches.
|
|
| 5. |
- Jakubavičiūtė, Eglė, et al.
(författare)
-
DNA metabarcoding reveals diverse diet of the three-spined stickleback in a coastal ecosystem.
- 2017
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:10
-
Tidskriftsartikel (refereegranskat)abstract
- The three-spined stickleback (Gasterosteus aculeatus L., hereafter 'stickleback') is a common mesopredatory fish in marine, coastal and freshwater areas. In large parts of the Baltic Sea, stickleback densities have increased >10-fold during the last decades, and it is now one of the dominating fish species both in terms of biomass and effects on lower trophic levels. Still, relatively little is known about its diet-knowledge which is essential to understand the increasing role sticklebacks play in the ecosystem. Fish diet analyses typically rely on visual identification of stomach contents, a labour-intensive method that is made difficult by prey digestion and requires expert taxonomic knowledge. However, advances in DNA-based metabarcoding methods promise a simultaneous identification of most prey items, even from semi-digested tissue. Here, we studied the diet of stickleback from the western Baltic Sea coast using both DNA metabarcoding and visual analysis of stomach contents. Using the cytochrome oxidase (CO1) marker we identified 120 prey taxa in the diet, belonging to 15 phyla, 83 genera and 84 species. Compared to previous studies, this is an unusually high prey diversity. Chironomids, cladocerans and harpacticoids were dominating prey items. Large sticklebacks were found to feed more on benthic prey, such as amphipods, gastropods and isopods. DNA metabarcoding gave much higher taxonomic resolution (median rank genus) than visual analysis (median rank order), and many taxa identified using barcoding could not have been identified visually. However, a few taxa identified by visual inspection were not revealed by barcoding. In summary, our results suggest that the three-spined stickleback feeds on a wide variety of both pelagic and benthic organisms, indicating that the strong increase in stickleback populations may affect many parts of the Baltic Sea coastal ecosystem.
|
|
| 6. |
- Leray, Matthieu, et al.
(författare)
-
Preparation of Amplicon Libraries for Metabarcoding of Marine Eukaryotes Using Illumina MiSeq: The Adapter Ligation Method
- 2016
-
Ingår i: Marine Genomics: Methods and Protocols. - New York : Springer. - 9781493937721 ; , s. 209-218
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Amplicon-based studies of marine microscopic eukaryotes, also referred to as metabarcoding studies, can be performed to analyze patterns of biodiversity or predator–prey interactions targeting the mitochondrial cytochrome oxidase 1 (CO1) or the small ribosomal subunit (SSU) markers. Because high-throughput sequencing (HTS) Illumina platforms provide millions of reads per run, hundreds of samples may be sequenced simultaneously. This protocol details the preparation of multiplexed amplicon libraries for Illumina MiSeq sequencing. We describe a strategy for sample multiplexing using a combination of tailed PCR primers and ligation of indexed adapters.
|
|
| 7. |
- Ritter, Camila, et al.
(författare)
-
The pitfalls of biodiversity proxies: Differences in richness patterns of birds, trees and understudied diversity across Amazonia
- 2019
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- © 2019, The Author(s). Most knowledge on biodiversity derives from the study of charismatic macro-organisms, such as birds and trees. However, the diversity of micro-organisms constitutes the majority of all life forms on Earth. Here, we ask if the patterns of richness inferred for macro-organisms are similar for micro-organisms. For this, we barcoded samples of soil, litter and insects from four localities on a west-to-east transect across Amazonia. We quantified richness as Operational Taxonomic Units (OTUs) in those samples using three molecular markers. We then compared OTU richness with species richness of two relatively well-studied organism groups in Amazonia: trees and birds. We find that OTU richness shows a declining west-to-east diversity gradient that is in agreement with the species richness patterns documented here and previously for birds and trees. These results suggest that most taxonomic groups respond to the same overall diversity gradients at large spatial scales. However, our results show a different pattern of richness in relation to habitat types, suggesting that the idiosyncrasies of each taxonomic group and peculiarities of the local environment frequently override large-scale diversity gradients. Our findings caution against using the diversity distribution of one taxonomic group as an indication of patterns of richness across all groups.
|
|
| 8. |
|
|
