scholarly journals Patterns of Cryptic Diversity and Phylogeography in Four Freshwater Copepod Crustaceans in European Lakes

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 448
Author(s):  
Elena Kochanova ◽  
Abhilash Nair ◽  
Natalia Sukhikh ◽  
Risto Väinölä ◽  
Arild Husby
Keyword(s):  
Sequence Data ◽  
Rrna Genes ◽  
Phylogeographic Structure ◽  
Cryptic Diversity ◽  
Widespread Species ◽  
Geographical Patterns ◽  
Mtdna Coi ◽  
Nuclear Its ◽  
Freshwater Copepods ◽  
18S Rrna Genes

Comparative phylogeography has become a powerful approach in exploring hidden or cryptic diversity within widespread species and understanding how historical and biogeographical factors shape the modern patterns of their distribution. Most comparative phylogeographic studies so far focus on terrestrial and vertebrate taxa, while aquatic invertebrates (and especially freshwater invertebrates) remain unstudied. In this article, we explore and compare the patterns of molecular diversity and phylogeographic structure of four widespread freshwater copepod crustaceans in European water bodies: the harpacticoids Attheyella crassa, Canthocamptus staphylinus and Nitokra hibernica, and the cyclopoid Eucyclops serrulatus, using sequence data from mtDNA COI and nuclear ITS/18S rRNA genes. The three taxa A. crassa, C. staphylinus and E. serrulatus each consist of deeply diverged clusters and are deemed to represent complexes of species with largely (but not completely) non-overlapping distributions, while in N. hibernica only little differentiation was found, which may however reflect the geographically more restricted sampling. However, the geographical patterns of subdivision differ. The divisions in A. crassa and E. serrulatus follow an east–west pattern in Northern Europe whereas that in C. staphylinus has more of a north–south pattern, with a distinct Fennoscandian clade. The deep mitochondrial splits among populations of A. crassa, C. staphylinus and E. serrulatus (model-corrected distances 26–36%) suggest that divergence of the lineages predate the Pleistocene glaciations. This study provides an insight into cryptic diversity and biogeographic distribution of freshwater copepods.

scholarly journals Investigating Microbial Eukaryotic Diversity from a Global Census: Insights from a Comparison of Pyrotag and Full-Length Sequences of 18S rRNA Genes

2014 ◽  
Vol 80 (14) ◽  
pp. 4363-4373 ◽  
Author(s):  
Alle A. Y. Lie ◽  
Zhenfeng Liu ◽  
Sarah K. Hu ◽  
Adriane C. Jones ◽  
Diane Y. Kim ◽  
...  
Keyword(s):  
Species Richness ◽  
Sanger Sequencing ◽  
18S Rrna ◽  
Sequence Data ◽  
Sequence Similarity ◽  
Hypervariable Region ◽  
Full Length ◽  
Rrna Genes ◽  
Data Sets ◽  
18S Rrna Genes

ABSTRACTNext-generation DNA sequencing (NGS) approaches are rapidly surpassing Sanger sequencing for characterizing the diversity of natural microbial communities. Despite this rapid transition, few comparisons exist between Sanger sequences and the generally much shorter reads of NGS. Operational taxonomic units (OTUs) derived from full-length (Sanger sequencing) and pyrotag (454 sequencing of the V9 hypervariable region) sequences of 18S rRNA genes from 10 global samples were analyzed in order to compare the resulting protistan community structures and species richness. Pyrotag OTUs called at 98% sequence similarity yielded numbers of OTUs that were similar overall to those for full-length sequences when the latter were called at 97% similarity. Singleton OTUs strongly influenced estimates of species richness but not the higher-level taxonomic composition of the community. The pyrotag and full-length sequence data sets had slightly different taxonomic compositions of rhizarians, stramenopiles, cryptophytes, and haptophytes, but the two data sets had similarly high compositions of alveolates. Pyrotag-based OTUs were often derived from sequences that mapped to multiple full-length OTUs at 100% similarity. Thus, pyrotags sequenced from a single hypervariable region might not be appropriate for establishing protistan species-level OTUs. However, nonmetric multidimensional scaling plots constructed with the two data sets yielded similar clusters, indicating that beta diversity analysis results were similar for the Sanger and NGS sequences. Short pyrotag sequences can provide holistic assessments of protistan communities, although care must be taken in interpreting the results. The longer reads (>500 bp) that are now becoming available through NGS should provide powerful tools for assessing the diversity of microbial eukaryotic assemblages.

Molecular identification ofSarcocystisspp. helped to define the origin of green pythons (Morelia viridis) confiscated in Germany

Parasitology ◽  
2013 ◽  
Vol 141 (5) ◽  
pp. 646-651 ◽  
Author(s):  
GASTÓN MORÉ ◽  
NIKOLA PANTCHEV ◽  
DALAND C. HERRMANN ◽  
MAJDA GLOBOKAR VRHOVEC ◽  
SABINE ÖFNER ◽  
...  
Keyword(s):  
18S Rrna ◽  
Sequence Data ◽  
18S Rrna Gene ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Intermediate Hosts ◽  
Apicomplexan Parasites ◽  
Large Numbers ◽  
Wide Range ◽  
18S Rrna Genes

SUMMARYSarcocystisspp. represent apicomplexan parasites. They usually have a heteroxenous life cycle. Around 200 species have been described, affecting a wide range of animals worldwide, including reptiles. In recent years, large numbers of reptiles have been imported into Europe as pets and, as a consequence, animal welfare and species protection issues emerged. A sample of pooled feces from four confiscated green pythons (Morelia viridis) containingSarcocystisspp. sporocysts was investigated. These snakes were imported for the pet trade and declared as being captive-bred. Full length 18S rRNA genes were amplified, cloned into plasmids and sequenced. Two differentSarcocystisspp. sequences were identified and registered asSarcocystissp. fromM. viridisin GenBank. Both showed a 95–97% sequence identity with the 18S rRNA gene ofSarcocystis singaporensis.Phylogenetic analysis positioned these sequences together with otherSarcocystisspp. from snakes and rodents as definitive and intermediate hosts (IH), respectively. Sequence data and also the results of clinical and parasitological examinations suggest that the snakes were definitive hosts forSarcocystisspp. that circulate in wild IH. Thus, it seems unlikely that the infected snakes had been legally bred. Our research shows that information on the infection of snakes withSarcocystisspp. may be used to assess compliance with regulations on the trade with wildlife species.

scholarly journals Dix-seq: An integrated pipeline for fast amplicon data analysis

2020 ◽  
Author(s):  
Yongjun wei ◽  
Tianqi Ren ◽  
Lei Zhang
Keyword(s):  
Sequence Data ◽  
Gene Diversity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Sequencing Technologies ◽  
Functional Gene Diversity ◽  
Internal Transcribed Spacer Sequences ◽  
The Common ◽  
18S Rrna Genes ◽  
Multiple Samples

AbstractThe amplicon derived from 16S rRNA genes, 18S rRNA genes, internal transcribed spacer sequences or other functional genes can be used to infer and evaluate microbial diversity or functional gene diversity. With the development of sequencing technologies, large amounts of amplicon data were generated. Several different software or pipelines had been developed for amplicon data analyses. However, most current software/pipelines require multistep and advanced programming skills. Moreover, they are often complex and time-consuming. Here, we introduced an integrated pipeline named Dix-seq for high-throughput amplicon sequence data processing (https://github.com/jameslz/dix-seq). Dix-seq integrates several different amplicon analysis algorithms and software for diversity analyses of multiple samples. Dix-seq analyzes amplicon sequences efficiently, and exports abundant visual results automatically with only one command in Linux environment. In summary, Dix-seq enables the common/advanced users to generate amplicon analysis results easily and offers a versatile and convenient tool for researchers.

scholarly journals Cryptic diversity in Lithobates warszewitschii (Amphibia, Anura, Ranidae)

ZooKeys ◽  
2019 ◽  
Vol 838 ◽  
pp. 49-69
Author(s):  
James Cryer ◽  
Felicity Wynne ◽  
Stephen J. Price ◽  
Robert Puschendorf
Keyword(s):  
Species Complex ◽  
Nucleotide Diversity ◽  
Sequence Data ◽  
Isolation By Distance ◽  
Phylogeographic Structure ◽  
Cryptic Diversity ◽  
Population Declines ◽  
The Status ◽  
Cryptic Species Complex ◽  
Geographic Populations

Lithobateswarszewitschii is a species of ranid frog distributed from southern Honduras to Panama. This species suffered severe population declines at higher elevations (above 500 m a.s.l.) from the 1980s to early 1990s, but there is more recent evidence of recovery in parts of its range. Here we advocate for the status of Lithobateswarszewitschii as a candidate cryptic species complex based on sequence data from mitochondrial genes CO1 and 16S. Using concatenated phylogenies, nucleotide diversity (K2P-π), net between group mean distance (NBGMD) (πnet) and species delimitation methods, we further elucidate cryptic diversity within this species. All phylogenies display polyphyletic lineages within Costa Rica and Panama. At both loci, observed genetic polymorphism (K2P-π) is also high within and between geographic populations, surpassing proposed species threshold values for amphibians. Additionally, patterns of phylogeographic structure are complicated for this species, and do not appear to be explained by geographic barriers or isolation by distance. These preliminary findings suggest L.warszewitschii is a wide-ranging species complex. Therefore, we propose further research within its wider range, and recommend integrative taxonomic assessment is merited to assess species status.

scholarly journals Disentangling the mechanisms shaping the surface ocean microbiota

2019 ◽  
Author(s):  
Ramiro Logares ◽  
Ina M. Deutschmann ◽  
Pedro C. Junger ◽  
Caterina R. Giner ◽  
Anders K. Krabberød ◽  
...  
Keyword(s):  
Sequence Data ◽  
Spatial Differentiation ◽  
Dispersal Limitation ◽  
Rrna Genes ◽  
Dna Sequence Data ◽  
Surface Ocean ◽  
Ecological Mechanisms ◽  
Global Biogeochemical Cycles ◽  
Main Components ◽  
18S Rrna Genes

Abstract Background The ocean microbiota modulates global biogeochemical cycles and changes in its configuration may have largescale consequences. Yet, the underlaying ecological mechanisms structuring it are unclear. Here we investigate how fundamental ecological mechanisms (selection, dispersal and ecological drift) shape the smallest members of the tropical and subtropical surface-ocean microbiota: prokaryotes and minute eukaryotes (picoeukaryotes). Furthermore, we investigate the agents exerting abiotic selection on this assemblage as well as the spatial patterns emerging from the action of ecological mechanisms. To explore the previous, we analysed the composition of surface-ocean prokaryotic and picoeukaryotic communities using DNA-sequence data (16S- and 18S-rRNA genes) collected during the circumglobal expeditions Malaspina-2010 and TARA-Oceans. Results We found that the two main components of the tropical and subtropical surface-ocean microbiota, prokaryotes and picoeukaryotes, appear to be structured by different ecological mechanisms. Picoeukaryotic communities were predominantly structured by dispersal-limitation, while prokaryotic counterparts appeared to be shaped by the combined action of dispersal-limitation, selection and drift. Temperature-driven selection appeared as a major factor influencing species co-occurrence networks in prokaryotes but not in picoeukaryotes, indicating that association patterns may contribute to understand ocean microbiota structure and response to selection. Other measured abiotic variables seemed to have limited selective effects on community structure in the tropical and subtropical ocean. Picoeukaryotes displayed a higher spatial differentiation between communities and a higher distance decay when compared to prokaryotes, consistent with a scenario of higher dispersal limitation in the former after considering environmental heterogeneity. Lastly, random dynamics or drift seemed to have a more important role in structuring prokaryotic communities than picoeukaryotic counterparts. Conclusions The differential action of ecological mechanisms seems to cause contrasting biogeography, in the tropical and subtropical ocean, among the smallest surface plankton, prokaryotes and picoeukaryotes. This suggests that the idiosyncrasy of the main constituents of the ocean microbiota should be considered in order to understand its current and future configuration, which is especially relevant in a context of global change, where the reaction of surface ocean plankton to temperature increase is still unclear.

scholarly journals Disentangling the mechanisms shaping the surface ocean microbiota

2020 ◽  
Author(s):  
Ramiro Logares ◽  
Ina M. Deutschmann ◽  
Pedro C. Junger ◽  
Caterina R. Giner ◽  
Anders K. Krabberød ◽  
...  
Keyword(s):  
Sequence Data ◽  
Spatial Differentiation ◽  
Dispersal Limitation ◽  
Rrna Genes ◽  
Dna Sequence Data ◽  
Surface Ocean ◽  
Ecological Mechanisms ◽  
Global Biogeochemical Cycles ◽  
Main Components ◽  
18S Rrna Genes

Abstract Background The ocean microbiota modulates global biogeochemical cycles and changes in its configuration may have largescale consequences. Yet, the underlying ecological mechanisms structuring it are unclear. Here we investigate how fundamental ecological mechanisms ( selection , dispersal and ecological drift ) shape the smallest members of the tropical and subtropical surface-ocean microbiota: prokaryotes and minute eukaryotes (picoeukaryotes). Furthermore, we investigate the agents exerting abiotic selection on this assemblage as well as the spatial patterns emerging from the action of ecological mechanisms. To explore the previous, we analysed the composition of surface-ocean prokaryotic and picoeukaryotic communities using DNA-sequence data (16S- and 18S-rRNA genes) collected during the circumglobal expeditions Malaspina-2010 and TARA-Oceans . Results We found that the two main components of the tropical and subtropical surface-ocean microbiota, prokaryotes and picoeukaryotes, appear to be structured by different ecological mechanisms. Picoeukaryotic communities were predominantly structured by dispersal-limitation, while prokaryotic counterparts appeared to be shaped by the combined action of dispersal-limitation, selection and drift. Temperature-driven selection appeared as a major factor, out of a few selected factors, influencing species co-occurrence networks in prokaryotes but not in picoeukaryotes, indicating that association patterns may contribute to understand ocean microbiota structure and response to selection. Other measured abiotic variables seemed to have limited selective effects on community structure in the tropical and subtropical ocean. Picoeukaryotes displayed a higher spatial differentiation between communities and a higher distance decay when compared to prokaryotes, consistent with a scenario of higher dispersal limitation in the former after considering environmental heterogeneity. Lastly, random dynamics or drift seemed to have a more important role in structuring prokaryotic communities than picoeukaryotic counterparts. Conclusions The differential action of ecological mechanisms seems to cause contrasting biogeography, in the tropical and subtropical ocean, among the smallest surface plankton, prokaryotes and picoeukaryotes. This suggests that the idiosyncrasy of the main constituents of the ocean microbiota should be considered in order to understand its current and future configuration, which is especially relevant in a context of global change, where the reaction of surface ocean plankton to temperature increase is still unclear.

Phylogeny of hymenolepidids (Cestoda: Cyclophyllidea) from mammals: sequences of 18S rRNA and COI genes confirm major clades revealed by the 28S rRNA analyses

2021 ◽  
Vol 95 ◽  
Author(s):  
B. Neov ◽  
G.P. Vasileva ◽  
G. Radoslavov ◽  
P. Hristov ◽  
D.T.J. Littlewood ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
18S Rrna ◽  
Phylogenetic Analyses ◽  
The Other ◽  
Rrna Genes ◽  
Host Switching ◽  
28S Rrna ◽  
Mitochondrial Cytochrome ◽  
Rapid Radiation ◽  
18S Rrna Genes

Abstract The aim of the study is to test a hypothesis for the phylogenetic relationships among mammalian hymenolepidid tapeworms, based on partial (D1–D3) nuclear 28S ribosomal RNA (rRNA) genes, by estimating new molecular phylogenies for the group based on partial mitochondrial cytochrome c oxidase I (COI) and nuclear 18S rRNA genes, as well as a combined analysis using all three genes. New sequences of COI and 18S rRNA genes were obtained for Coronacanthus integrus, C. magnihamatus, C. omissus, C. vassilevi, Ditestolepis diaphana, Lineolepis scutigera, Spasskylepis ovaluteri, Staphylocystis tiara, S. furcata, S. uncinata, Vaucherilepis trichophorus and Neoskrjabinolepis sp. The phylogenetic analyses confirmed the major clades identified by Haukisalmi et al. (Zoologica Scripta 39: 631–641, 2010): Ditestolepis clade, Hymenolepis clade, Rodentolepis clade and Arostrilepis clade. While the Ditestolepis clade is associated with soricids, the structure of the other three clades suggests multiple evolutionary events of host switching between shrews and rodents. Two of the present analyses (18S rRNA and COI genes) show that the basal relationships of the four mammalian clades are branching at the same polytomy with several hymenolepidids from birds (both terrestrial and aquatic). This may indicate a rapid radiation of the group, with multiple events of colonizations of mammalian hosts by avian parasites.

scholarly journals Eucaryotic Diversity in a Hypersaline Microbial Mat

2007 ◽  
Vol 74 (1) ◽  
pp. 329-332 ◽  
Author(s):  
Leah M. Feazel ◽  
John R. Spear ◽  
Alicia B. Berger ◽  
J. Kirk Harris ◽  
Daniel N. Frank ◽  
...  
Keyword(s):  
18S Rrna ◽  
Microbial Mat ◽  
Rrna Genes ◽  
Clone Libraries ◽  
18S Rrna Genes

ABSTRACT To determine the eucaryotic diversity of the hypersaline Guerrero Negro microbial mat, we amplified 18S rRNA genes from DNA extracted from this mat and constructed and analyzed clone libraries. The extent of eucaryotic diversity detected was remarkably low, only 15 species among 890 clones analyzed. Six eucaryotic kingdoms were represented, as well as a novel cluster of sequences. Nematode sequences dominated the clone libraries.

Molecular Systematics of Tribe Physarieae (Brassicaceae) Based on Nuclear ITS, LUMINIDEPENDENS, and Chloroplast ndhF

2021 ◽  
Author(s):  
Sara Fuentes-Soriano ◽  
Elizabeth A. Kellogg
Keyword(s):  
Sequence Data ◽  
Plastid Dna ◽  
Sister Relationship ◽  
Data Set ◽  
Woody Perennial ◽  
History Of ◽  
Nuclear Its ◽  
Phylogenetic Framework ◽  
Phylogenetic Hypotheses ◽  
Relationship Of

Physarieae is a small tribe of herbaceous annual and woody perennial mustards that are mostly endemic to North America, with its members including a large amount of variation in floral, fruit, and chromosomal variation. Building on a previous study of Physarieae based on morphology and ndhF plastid DNA, we reconstructed the evolutionary history of the tribe using new sequence data from two nuclear markers, and compared the new topologies against previously published cpDNA-based phylogenetic hypotheses. The novel analyses included ca. 420 new sequences of ITS and LUMINIDEPENDENS (LD) markers for 39 and 47 species, respectively, with sampling accounting for all seven genera of Physarieae, including nomenclatural type species, and 11 outgroup taxa. Maximum parsimony, maximum likelihood, and Bayesian analyses showed that these additional markers were largely consistent with the previous ndhF data that supported the monophyly of Physarieae and resolved two major clades within the tribe, i.e., DDNLS (Dithyrea, Dimorphocarpa, Nerisyrenia, Lyrocarpa, and Synthlipsis)and PP (Paysonia and Physaria). New analyses also increased internal resolution for some closely related species and lineages within both clades. The monophyly of Dithyrea and the sister relationship of Paysonia to Physaria was consistent in all trees, with the sister relationship of Nerisyrenia to Lyrocarpa supported by ndhF and ITS, and the positions of Dimorphocarpa and Synthlipsis shifted within the DDNLS Clade depending on the employed data set. Finally, using the strong, new phylogenetic framework of combined cpDNA + nDNA data, we discussed standing hypotheses of trichome evolution in the tribe suggested by ndhF.

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