scholarly journals From metabarcoding to metaphylogeography: separating the wheat from the chaff

2019 ◽  
Author(s):  
Xavier Turon ◽  
Adrià Antich ◽  
Creu Palacín ◽  
Kim Præbel ◽  
Owen Simon Wangensteen
Keyword(s):  
Genetic Variability ◽  
Sequence Data ◽  
Β Diversity ◽  
Haplotype Networks ◽  
Main Challenge ◽  
Invasion Genetics ◽  
Sanger Sequence ◽  
Long Time ◽  
Codon Positions ◽  
Occurrence Patterns

AbstractMetabarcoding is by now a well-established method for biodiversity assessment in terrestrial, freshwater and marine environments. Metabarcoding datasets are usually used for α- and β-diversity estimates, that is, interspecies (or inter-MOTU) patterns. However, the use of hypervariable metabarcoding markers may provide an enormous amount of intraspecies (intra-MOTU) information - mostly untapped so far. The use of cytochrome oxidase (COI) amplicons is gaining momentum in metabarcoding studies targeting eukaryote richness. COI has been for a long time the marker of choice in population genetics and phylogeographic studies. Therefore, COI metabarcoding datasets may be used to study intraspecies patterns and phylogeographic features for hundreds of species simultaneously, opening a new field which we suggest to name metaphylogeography. The main challenge for the implementation of this approach is the separation of erroneous sequences from true intra-MOTU variation. Here, we develop a cleaning protocol based on changes in entropy of the different codon positions of the COI sequence, together with co-occurrence patterns of sequences. Using a dataset of community DNA from several benthic littoral communities in the Mediterranean and Atlantic seas, we first tested by simulation on a subset of sequences a two-step cleaning approach consisting of a denoising step followed by a minimal abundance filtering. The procedure was then applied to the whole dataset. We obtained a total of 563 MOTUs that were usable for phylogeographic inference. We used semiquantitative rank data instead of read abundances to perform AMOVAs and haplotype networks. Genetic variability was mainly concentrated within samples, but with an important between-seas component as well. There were inter-group differences in the amount of variability between and within communities in each sea. For two species the results could be compared with traditional Sanger sequence data available for the same zones, giving similar patterns. Our study shows that metabarcoding data can be used to infer intra- and interpopulation genetic variability of many species at a time, providing a new method with great potential for basic biogeography, connectivity and dispersal studies, and for the more applied fields of conservation genetics, invasion genetics, and design of protected areas.

scholarly journals Introducing mothur: Open-Source, Platform-Independent, Community-Supported Software for Describing and Comparing Microbial Communities

2009 ◽  
Vol 75 (23) ◽  
pp. 7537-7541 ◽  
Author(s):  
Patrick D. Schloss ◽  
Sarah L. Westcott ◽  
Thomas Ryabin ◽  
Justine R. Hall ◽  
Martin Hartmann ◽  
...  
Keyword(s):  
16S Rrna ◽  
Software Package ◽  
Sequence Data ◽  
Rrna Gene ◽  
Sequencing Data ◽  
Laptop Computer ◽  
Operational Taxonomic Units ◽  
Β Diversity ◽  
Single Piece

ABSTRACT mothur aims to be a comprehensive software package that allows users to use a single piece of software to analyze community sequence data. It builds upon previous tools to provide a flexible and powerful software package for analyzing sequencing data. As a case study, we used mothur to trim, screen, and align sequences; calculate distances; assign sequences to operational taxonomic units; and describe the α and β diversity of eight marine samples previously characterized by pyrosequencing of 16S rRNA gene fragments. This analysis of more than 222,000 sequences was completed in less than 2 h with a laptop computer.

Sanger sequence data

UQ eSpace ◽  
2021 ◽  
Author(s):  
Mohamed Cassim Mohamed Zakeel ◽  
Akinsanmi Olufemi ◽  
Geering Andrew
Keyword(s):  
Sequence Data ◽  
Sanger Sequence

Contrasting the population genetic structure of two velvet worm taxa (Onychophora : Peripatopsidae : Peripatopsis) in forest fragments along the south-eastern Cape, South Africa

2017 ◽  
Vol 31 (6) ◽  
pp. 781 ◽  
Author(s):  
Savel R. Daniels ◽  
Megan Dreyer ◽  
Prashant P. Sharma
Keyword(s):  
South Africa ◽  
Population Genetic ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Forest Fragments ◽  
Eastern Cape ◽  
Dna Sequence Data ◽  
Mtdna Coi ◽  
Haplotype Networks ◽  
Velvet Worm

During the present study, we examined the phylogeography and systematics of two species of velvet worm (Peripatopsis Pocock, 1894) in the forested region of the southern Cape of South Africa. A total of 89 P. moseleyi (Wood-Mason, 1879) and 65 P. sedgwicki (Purcell, 1899) specimens were collected and sequenced for the cytochrome c oxidase subunit I mtDNA (COI). In addition, a single P. sedgwicki specimen per sample locality was sequenced for the 18S rRNA locus. Furthermore, morphological variation among P. sedgwicki sample localities were explored using traditional alpha taxonomic characters. DNA sequence data were subjected to phylogenetic analyses using Bayesian inference and population genetic analyses using haplotype networks and analyses of molecular variance (AMOVAs). Phylogenetic results revealed the presence of four and three clades within P. moseleyi and P. sedgwicki respectively. Haplotype networks were characterised by the absence of shared haplotypes between clades, suggesting genetic isolation, a result corroborated by the AMOVA and highly significant FST values. Specimens from Fort Fordyce Nature Reserve were both genetically and morphologically distinct from the two remaining P. sedgwicki clades. The latter result suggests the presence of a novel lineage nested within P. sedgwicki and suggests that species boundaries within this taxon require re-examination.

Phylogenetic Relations of Rhizoplaca Zopf. from Anatolia Inferred from ITS Sequence Data

2006 ◽  
Vol 61 (5-6) ◽  
pp. 405-412 ◽  
Author(s):  
Demet Cansaran ◽  
Sümer Aras ◽  
İrfan Kandemir ◽  
Gökhan Halıcı
Keyword(s):  
Genetic Variability ◽  
Phylogenetic Tree ◽  
Sequence Data ◽  
Volcanic Rocks ◽  
Morphological Characteristics ◽  
Its Rdna ◽  
Its Sequence ◽  
Phylogenetic Relations ◽  
Rdna Sequences

Like many lichen-forming fungi, species of the genus Rhizoplaca have wide geographical distributions, but studies of their genetic variability are limited. The information about the ITS rDNA sequences of three species of Rhizoplaca from Anatolia was generated and aligned with other species from other countries and also with the data belonging to Lecanora species. The examined species were collected from the volcanic rocks of Mount Erciyes which is located in the middle of Anatolia (Turkey). The sequence data aligned with eight other samples of Rhizoplaca and six different species of Lecanora were obtained from GenBank. The results support the concept maintained by Arup and Grube (2000) that Rhizoplaca may not be a genus separate from Lecanora. According to the phylogenetic tree, Rhizoplaca melanopthalma from Turkey with two different samples of R. melanopthalma from Arizona (AF159929, AF159934) and a sample from Austria formed a group under the same branch. R. peltata and R. chrysoleuca samples from Anatolia located in two other branches of the tree formed sister groups with the samples of the same species from different countries. Although R. peltata remained on the same branch with other samples of the same species from other countries it was placed in a different branch within the group. When the three species from Anatolia were considered alone, it was noticed that Rhizoplaca melanopthalma and Rhizoplaca peltata are phylogenetically closer to each other than Rhizoplaca chrysoleuca; the morphological characteristics also support this result.

scholarly journals Uwarunkowania procesu pojednania w Kambodży

2020 ◽  
Vol 14 ◽  
pp. 267-280
Author(s):  
Radosław Zarzecki
Keyword(s):  
Early Stage ◽  
Khmer Rouge ◽  
State Level ◽  
Political Life ◽  
Historical Background ◽  
Difficult Situation ◽  
Main Challenge ◽  
Long Time ◽  
History Of ◽  
Culture Of Silence

Determinants of Reconciliation in Cambodia Forty years after Cambodian genocide the reconciliation is still in early stage. Despite such long time there was almost nothing done, especially in 20th century, to make that process happened. The article discusses the determinants, reasons and factors that had impact on reconciliation. Determinants can be divided into different categories. First of all the socio-historical background. Circumstances in which Khmer Rouge come to power, their revolutionary approach to economy, implemented reforms, use of children, displacements of people and categorization of citizens had great impact on post-1979 Cambodia. Another determinant is a political one. Policy of post-Khmer Rouge Cambodia rulers stunted the reconciliation. There reason of such actions are multidimensional but the most important one is provenance of People’s Republic of Kampuchea leaders. The most important figures in Cambodia politics are ex-Khmer Rouge soldiers, accused by some of taking a part in genocide. What’s even more confusing, the most powerful opposition party in 1980s were perpetrators themselves and their allies. Even after signing Paris Peace Accords in 1991 until early 2000s there was no will to punish Khmer Rouge officials responsible for genocide. The Cambodian culture of silence, the third determinant, only exacerbates a difficult situation. Cambodians rarely speak about atrocities and harsh past because of fear, shame or trauma. Even in school textbooks until 2009 there was almost nothing said about tragic events which happened between 1975 and 1979. History of Democratic Kampuchea still affects the Cambodian society. Despite sentencing few Khmer Rouge officials in 2010s, there’s still lot to be done also on state-level. Reconciliation and coming back to the state of balance is the main challenge for Cambodia in the nearest future, crucially important to social and political life of this nation.

scholarly journals Cytotoxic, Genotoxic, and Polymorphism Effects on Vanilla planifolia Jacks ex Andrews after Long-Term Exposure to Argovit® Silver Nanoparticles

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 754 ◽  
Author(s):  
Jericó Bello-Bello ◽  
José Spinoso-Castillo ◽  
Samantha Arano-Avalos ◽  
Eduardo Martínez-Estrada ◽  
María Arellano-García ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Large Scale ◽  
Inter Simple Sequence Repeat ◽  
Metallic Silver ◽  
Vanilla Planifolia ◽  
Genotoxic Effects ◽  
Total Percentage ◽  
Long Time ◽  
Mexican Government

Worldwide demands of Vanilla planifolia lead to finding new options to produce large-scale and contaminant-free crops. Particularly, the Mexican Government has classified Vanilla planifolia at risk and it subject to protection programs since wild species are in danger of extinction and no more than 30 clones have been found. Nanotechnology could help to solve both demands and genetic variability, but toxicological concerns must be solved. In this work, we present the first study of the cytotoxic and genotoxic effects promoted by AgNPs in Vanilla planifolia plantlets after a very long exposure time of six weeks. Our results show that Vanilla planifolia plantlets growth with doses of 25 and 50 mg/L is favored with a small decrease in the mitotic index. A dose-dependency in the frequency of cells with chromosomal aberrations and micronuclei was found. However, genotoxic effects could be considered as minimum due to with the highest concentration employed (200 mg/L), the total percentage of chromatic aberrations is lower than 5% with only three micronuclei in 3000 cells, despite the long-time exposure to AgNP. Therefore, 25 and 50 mg/L (1.5 and 3 mg/L of metallic silver) were identified as safe concentrations for Vanilla planifolia growth on in vitro conditions. Exposure of plantlets to AgNPs increase the polymorphism registered by inter-simple sequence repeat method (ISSR), which could be useful to promote the genetic variability of this species.

scholarly journals Phylogenomics of parasitic and non-parasitic lice (Insecta: Psocodea): Combining sequence data and Exploring compositional bias solutions in Next Generation Datasets

2020 ◽  
Author(s):  
Robert S de Moya ◽  
Kazunori Yoshizawa ◽  
Kimberly K O Walden ◽  
Andrew D Sweet ◽  
Christopher H Dietrich ◽  
...  
Keyword(s):  
Sequence Data ◽  
Compositional Bias ◽  
Phylogenomic Analysis ◽  
Data Set ◽  
Genomic Changes ◽  
Insect Order ◽  
Codon Positions ◽  
Phylogenomic Analyses ◽  
Ordinal Level ◽  
Likelihood Mapping

Abstract The insect order Psocodea is a diverse lineage comprising both parasitic (Phthiraptera) and non-parasitic members (Psocoptera). The extreme age and ecological diversity of the group may be associated with major genomic changes, such as base compositional biases expected to affect phylogenetic inference. Divergent morphology between parasitic and non-parasitic members has also obscured the origins of parasitism within the order. We conducted a phylogenomic analysis on the order Psocodea utilizing both transcriptome and genome sequencing to obtain a data set of 2,370 orthologous genes. All phylogenomic analyses, including both concatenated and coalescent methods suggest a single origin of parasitism within the order Psocodea, resolving conflicting results from previous studies. This phylogeny allows us to propose a stable ordinal level classification scheme that retains significant taxonomic names present in historical scientific literature and reflects the evolution of the group as a whole. A dating analysis, with internal nodes calibrated by fossil evidence, suggests an origin of parasitism that predates the K-Pg boundary. Nucleotide compositional biases are detected in third and first codon positions and result in the anomalous placement of the Amphientometae as sister to Psocomorpha when all nucleotide sites are analyzed. Likelihood-mapping and quartet sampling methods demonstrate that base compositional biases can also have an effect on quartet-based methods.

scholarly journals Asexual Propagation of a Virulent Clone Complex in a Human and Feline Outbreak of Sporotrichosis

2014 ◽  
Vol 14 (2) ◽  
pp. 158-169 ◽  
Author(s):  
Marcus de Melo Teixeira ◽  
Anderson Messias Rodrigues ◽  
Clement K. M. Tsui ◽  
Luiz Gonzaga Paulo de Almeida ◽  
Anne D. Van Diepeningen ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Mating Type ◽  
Sequence Data ◽  
Fungal Infections ◽  
Haplotype Diversity ◽  
Sporothrix Schenckii ◽  
Mitogen Activated Protein Kinase ◽  
Comparative Genomic ◽  
Asexual Propagation ◽  
Content Type

ABSTRACT Sporotrichosis is one of the most frequent subcutaneous fungal infections in humans and animals caused by members of the plant-associated, dimorphic genus Sporothrix . Three of the four medically important Sporothrix species found in Brazil have been considered asexual as no sexual stage has ever been reported in Sporothrix schenckii , Sporothrix brasiliensis , or Sporothrix globosa . We have identified the mating type ( MAT ) loci in the S. schenckii (strain 1099-18/ATCC MYA-4821) and S. brasiliensis (strain 5110/ATCC MYA-4823) genomes by using comparative genomic approaches to determine the mating type ratio in these pathogen populations. Our analysis revealed the presence of a MAT1-1 locus in S. schenckii while a MAT1-2 locus was found in S. brasiliensis representing genomic synteny to other Sordariomycetes . Furthermore, the components of the mitogen-activated protein kinase (MAPK)-pheromone pathway, pheromone processing enzymes, and meiotic regulators have also been identified in the two pathogens, suggesting the potential for sexual reproduction. The ratio of MAT1-1 to MAT1-2 was not significantly different from 1:1 for all three Sporothrix species, but the population of S. brasiliensis in the outbreaks originated from a single mating type. We also explored the population genetic structure of these pathogens using sequence data of two loci to improve our knowledge of the pattern of geographic distribution, genetic variation, and virulence phenotypes. Population genetics data showed significant population differentiation and clonality with a low level of haplotype diversity in S. brasiliensis isolates from different regions of sporotrichosis outbreaks in Brazil. In contrast, S. schenckii isolates demonstrated a high degree of genetic variability without significant geographic differentiation, indicating the presence of recombination. This study demonstrated that two species causing the same disease have contrasting reproductive strategies and genetic variability patterns.

scholarly journals Occurrence and genetic variability of Candida parapsilosis sensu lato in Hungary

2007 ◽  
Vol 56 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Sándor Kocsubé ◽  
Mónika Tóth ◽  
Csaba Vágvölgyi ◽  
Ilona Dóczi ◽  
Miklós Pesti ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Candida Parapsilosis ◽  
Sequence Data ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Its Region ◽  
Molecular Data ◽  
Rrna Gene ◽  
Phenotypic Data ◽  
Group I

The occurrence and genetic variability of Candida parapsilosis isolates in two Hungarian hospitals, located in Debrecen and Pécs, were examined. Among the 209 Candida isolates examined, 20 were found to belong to C. parapsilosis sensu lato, based on morphological, physiological and molecular data. The frequency of occurrence of C. parapsilosis isolates (9.6 %) was lower than that observed in Europe but higher than that observed previously in Hungary. The genetic variability of C. parapsilosis sensu lato isolates was also examined using random amplified polymorphic DNA (RAPD) analysis and sequence analysis of the intergenic transcribed spacer (ITS) region of the rRNA gene cluster. The genetic variability of the isolates was relatively high, as revealed by RAPD analysis. Two isolates were found to belong to the recently described Candida metapsilosis species (C. parapsilosis group III), based on ITS sequence data, RAPD analysis and phenotypic data. These two isolates could also be distinguished from C. parapsilosis sensu stricto isolates using a primer pair developed for the detection of C. parapsilosis group I isolates. To the best of the authors' knowledge, this is the first report on the identification of C. metapsilosis from bloodstream infection.

scholarly journals Phylogeny of the species-rich Pilea Lindl. (Urticaceae) supports its revised delimitation and infrageneric classification, including the resurrection of Achudemia Blume

2020 ◽  
Author(s):  
Long-Fei Fu ◽  
Fang Wen ◽  
Olivier Maurin ◽  
Michele Rodda ◽  
Yi-Gang Wei ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Sequence Data ◽  
Fruit Size ◽  
Monophyletic Clade ◽  
Infrageneric Classification ◽  
Sanger Sequence ◽  
Nuclear Regions ◽  
First Time ◽  
Scientific Questions ◽  
Do So

ABSTRACTPilea Lindl., with 933 published names is the largest genus within the Urticaceae. Pilea was last monographed in 1869 and whilst the monophyly of the genus has been proposed by previous authors, this has been based on incomplete taxon sampling and the failure to resolve the position of key taxa. We aimed to generate a robust phylogeny for Pilea and allied genera that could provide a framework for testing the monophyly of Pilea, revising its delimitation and for answering broader scientific questions about this species-rich genus. To do so, we sought to sample taxa representative of previous infrageneric classifications and with anomalous inflorescences or flower configurations and to use the resulting phylogeny to evaluate the delimitation of Pilea and to establish an infrageneric classification. In addition, we included a representative of the Polynesian genus Haroldiella which, morphologically, is very similar to Pilea. Using Sanger sequence data from two plastid and one nuclear regions we constructed a phylogeny using Bayesian Inference, Maximum Likelihood and Maximum Parsiomony approaches. We used our phylogeny to evaluate the informativness of 19 morphological traits and applied both to delimit a monophyletic genus and infrageneric sections. Our results recovered Pilea as paraphyletic with respect to Lecanthus, a consequence of the recovery of a monophyletic clade comprising sections Achudemia and Smithiella, neither of which had been adequately sampled in previous studies. We also recovered Pilea as polyphyletic with respect to Haroldiella. We identified isomery between male and female flowers, flower part number and male sepal arrangement as being phylogenetically informative traits that can be used to delimit two genera, Achudemia, including section Smithiella, recovered as sister to Lecanthus, and Pilea, including Haroldiella, recovered as sister to both. On the basis of our evaluation of both morphological traits and phylogenetic relationships we propose a new infrageneric classification for the genus comprising seven sections, five of which we describe for the first time, § Trimeris Y.G.Wei & A.K.Monro, § Lecanthoides C.J.Chen, § Angulata L.F.Fu & Y.G.Wei, § Tetrameris C.J.Chen, § Verrucosa L.F.Fu & Y.G.Wei, § Plataniflora L.F.Fu & Y.G.Wei and § Leiocarpa L.F.Fu & Y.G.Wei. We also identify a trend of decreasing merism and fruit size, and increasing species-richness as Pilea diverges. In addition, we recover strong geographical structure within our phylogeny, sufficient to propose that Pilea originated in the IndoMalaya biogeographic domain.

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