scholarly journals METAWORKS: A flexible, scalable bioinformatic pipeline for multi-marker biodiversity assessments

2020 ◽  
Author(s):  
Teresita M. Porter ◽  
Mehrdad Hajibabaei

AbstractBackgroundMulti-marker metabarcoding is increasingly being used to generate biodiversity information across different domains of life from microbes to fungi to animals such as in ecological and environmental studies. Current popular bioinformatic pipelines support microbial and fungal marker analysis, while ad hoc methods are used to process animal metabarcode markers from the same study. The purpose of this paper is to introduce MetaWorks, a ‘meta’barcode pipeline that does ‘the works’ and supports the bioinformatic processing of various metabarcoding markers including rRNA and their spacers as well as protein coding loci.ResultsMetaWorks provides a Conda environment to quickly gather most of the programs and dependencies for the pipeline. MetaWorks is automated using Snakemake to ensure reproducibility and scalability. We have supplemented existing RDP-trained classifiers for SSU (prokaryotes), ITS (fungi), and LSU (fungi) with trained classifiers for COI (eukaryotes), rbcL (diatoms or eukaryotes), SSU (diatoms or eukaryotes), and 12S (fish). MetaWorks can process rRNA genes, but it can also properly handle ITS spacers by trimming flanking conserved rRNA gene regions, as well as handle protein coding genes by removing obvious pseudogenes.ConclusionsAs far as we are aware, MetaWorks is the first flexible multi-marker metabarcode pipeline that can accommodate rRNA genes, spacer, and protein coding markers in the same pipeline. This is ideal for large-scale, multi-marker studies to provide a harmonized processing environment, pipeline, and taxonomic assignment approach. Updates to MetaWorks will be made as needed to reflect advances in the underlying programs, reference databases, or hidden Markov model (HMM) profiles for pseudogene filtering. Future developments will include support for additional metabarcode markers, RDP trained reference databases, and HMM profiles for pseudogene filtering.

2020 ◽  
Vol 21 (24) ◽  
pp. 9746
Author(s):  
Shahina Akter ◽  
Sun-Young Lee ◽  
Muhammad Zubair Siddiqi ◽  
Sri Renukadevi Balusamy ◽  
Md. Ashrafudoulla ◽  
...  

It is essential to develop and discover alternative eco-friendly antibacterial agents due to the emergence of multi-drug-resistant microorganisms. In this study, we isolated and characterized a novel bacterium named Terrabacter humi MAHUQ-38T, utilized for the eco-friendly synthesis of silver nanoparticles (AgNPs) and the synthesized AgNPs were used to control multi-drug-resistant microorganisms. The novel strain was Gram stain positive, strictly aerobic, milky white colored, rod shaped and non-motile. The optimal growth temperature, pH and NaCl concentration were 30 °C, 6.5 and 0%, respectively. Based on 16S rRNA gene sequence, strain MAHUQ-38T belongs to the genus Terrabacter and is most closely related to several Terrabacter type strains (98.2%–98.8%). Terrabacter humi MAHUQ-38T had a genome of 5,156,829 bp long (19 contigs) with 4555 protein-coding genes, 48 tRNA and 5 rRNA genes. The culture supernatant of strain MAHUQ-38T was used for the eco-friendly and facile synthesis of AgNPs. The transmission electron microscopy (TEM) image showed the spherical shape of AgNPs with a size of 6 to 24 nm, and the Fourier transform infrared (FTIR) analysis revealed the functional groups responsible for the synthesis of AgNPs. The synthesized AgNPs exhibited strong anti-bacterial activity against multi-drug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 6.25/50 and 12.5/50 μg/mL, respectively. The AgNPs altered the cell morphology and damaged the cell membrane of pathogens. This study encourages the use of Terrabacter humi for the ecofriendly synthesis of AgNPs to control multi-drug-resistant microorganisms.


Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 647
Author(s):  
Cassandra Koga ◽  
Greg W. Rouse

Stomatopoda, commonly known as mantis shrimps, are notable for their enlarged second maxillipeds encompassing the raptorial claw. The form of the claw can be used to divide them into two basic groups: smashers and spearers. Previous phylogenetic studies of Stomatopoda have focused on morphology or a few genes, though there have been whole mitochondrial genomes published for 15 members of Stomatopoda. However, the sampling has been somewhat limited with key taxa not included. Here, nine additional stomatopod mitochondrial genomes were generated and combined with the other available mitogenomes for a phylogenetic analysis. We used the 13 protein coding genes, as well as 12S rRNA, 16S rRNA genes, and included nuclear 18S rRNA gene sequences. Different rooting options were used for the analyses: (1) single and multiple outgroups from various eumalocostracan relatives and (2) a stomatopod-only dataset, with Hemisquilla californiensis used to root the topologies, based on the current hypothesis that Hemisquilla is the sister group to the rest of Stomatopoda. The eumalocostracan-rooted analyses all showed H. californiensis nested within Stomatopoda, raising doubts as to previous hypotheses as to its placement. Allowing for the rooting difference, the H. californiensis outgroup datasets had the same tree topology as the eumalocostracan outgroup datasets with slight variation at poorly supported nodes. Of the major taxonomic groupings sampled to date, Squilloidea was generally found to be monophyletic while Gonodactyloidea was not. The position of H. californiensis was found inside its superfamily, Gonodactyloidea, and grouped in a weakly supported clade containing Odontodactylus havanensis and Lysiosquillina maculata for the eumalocostracan-rooted datasets. An ancestral state reconstruction was performed on the raptorial claw form and provides support that spearing is the ancestral state for extant Stomatopoda, with smashing evolving subsequently one or more times.


2020 ◽  
Author(s):  
M. Mirdita ◽  
M. Steinegger ◽  
F. Breitwieser ◽  
J. Söding ◽  
E. Levy Karin

SummaryMMseqs2 taxonomy is a new tool to assign taxonomic labels to metagenomic contigs. It extracts all possible protein fragments from each contig, quickly retains those that can contribute to taxonomic annotation, assigns them with robust labels and determines the contig’s taxonomic identity by weighted voting. Its fragment extraction step is suitable for the analysis of all domains of life. MMseqs2 taxonomy is 2-18x faster than state-of-the-art tools and also contains new modules for creating and manipulating taxonomic reference databases as well as reporting and visualizing taxonomic assignments.AvailabilityMMseqs2 taxonomy is part of the MMseqs2 free open-source software package available for Linux, macOS and Windows at https://mmseqs.com.


2005 ◽  
Vol 187 (18) ◽  
pp. 6258-6264 ◽  
Author(s):  
Konstantinos T. Konstantinidis ◽  
James M. Tiedje

ABSTRACT The ranks higher than the species in the prokaryotic taxonomy are primarily designated based on phylogenetic analysis of the 16S rRNA gene sequences, but no definite standards exist for the absolute relatedness (measured by 16S rRNA or other means) between the ranks. Accordingly, it remains unknown how comparable the ranks are between different organisms. To gain insights into this question, we studied the relationship between shared gene content and genetic relatedness for 175 fully sequenced strains, using as a robust measure of relatedness the average amino acid identity (AAI) of the shared genes. Our results reveal that adjacent ranks (e.g., phylum versus class) frequently show extensive overlap in terms of genetic and gene content relatedness of the grouped organisms, and hence, the current system is of limited predictive power in this respect. The overlap between nonadjacent ranks (e.g., phylum versus family) is generally limited and attributable to clear inconsistencies of the taxonomy. In addition to providing means for standardizing taxonomy, our AAI-based approach provides a means to evaluate the robustness of alternative genetic markers for phylogenetic purposes. For instance, the 23S rRNA gene was found to be as good a marker as the 16S rRNA gene, while several of the widely distributed protein-coding genes, such as the RNA polymerase and gyrase subunits, show a strong phylogenetic signal, albeit less strong than the rRNA genes (0.78 > R 2 > 0.69 for the protein-coding genes versus R 2 = 0.84 for the rRNA genes). The AAI approach outlined here could contribute significantly to a genome-based taxonomy for all microbial organisms.


Genetika ◽  
2015 ◽  
Vol 47 (1) ◽  
pp. 311-321 ◽  
Author(s):  
Marija Rajicic ◽  
Tanja Adnadjevic ◽  
Gorana Stamenkovic ◽  
Jelena Blagojevic ◽  
Mladen Vujosevic

B chromosomes (Bs) are a very heterogeneous group of extra chromosomes. In various species Bs occur with different nucleotide sequences ranging from repetitive to protein coding. In yellow-necked field mice, Apodemus flavicollis Bs are small euchromatic chromosomes and untill now, only few molecular analyses have been conducted. In this study we examined A. flavicollis individuals with different number of Bs for presence of two genes, C-KIT and 18S rRNA. The C-KIT proto-oncogene was found on Bs in three Canidae species and one Cervidae species. This gene is a coding receptor critical for proliferation and cell differentiation of hematopoietic, melanoblast and primordial germ cells, and is highly conserved within mammals. While using semiquantitative PCR, we did not notice any difference in the C-KIT band intensity among animals with different number of Bs (0-3). The presence of only one copy of C- KIT gene was confirmed using real time-PCR on genomic DNA of A. flavicollis specimens with different number of Bs. rRNA genes in eukaryotes? genome are organized like units of tandem repeated sequences. The units form distinct clusters on one to several chromosome pairs. rRNA genes were found on Bs in different species including two species of genus Apodemus. One particular sample with 2 Bs showed the number of 18S rRNA gene about three times that of the calibrator 0 B sample. This result can indicate the presence of 18S rRNA gene on Bs, but its confirmation requires the implementation of other methods. Still, we can neither confirm nor deny the existence of pseudogen of tested target genes, or lose of exon 1 of C-KIT protooncogen in Bs of A. flavicollis. Our findings are further discussed.


2020 ◽  
Vol 11 ◽  
Author(s):  
Xiaolin Li ◽  
Lijiao Li ◽  
Zhijie Bao ◽  
Wenying Tu ◽  
Xiaohui He ◽  
...  

In the present study, the mitogenome of Tuber calosporum was assembled and analyzed. The mitogenome of T. calosporum comprises 15 conserved protein-coding genes, two rRNA genes, and 14 tRNAs, with a total size of 287,403 bp. Fifty-eight introns with 170 intronic open reading frames were detected in the T. calosporum mitogenome. The intronic region occupied 69.41% of the T. calosporum mitogenome, which contributed to the T. calosporum mitogenome significantly expand relative to most fungal species. Comparative mitogenomic analysis revealed large-scale gene rearrangements occurred in the mitogenome of T. calosporum, involving gene relocations and position exchanges. The mitogenome of T. calosporum was found to have lost several tRNA genes encoding for cysteine, aspartate, histidine, etc. In addition, a pair of fragments with a total length of 32.91 kb in both the nuclear and mitochondrial genomes of T. calosporum was detected, indicating possible gene transfer events. A total of 12.83% intragenomic duplications were detected in the T. calosporum mitogenome. Phylogenetic analysis based on mitochondrial gene datasets obtained well-supported tree topologies, indicating that mitochondrial genes could be reliable molecular markers for phylogenetic analyses of Ascomycota. This study served as the first report on mitogenome in the family Tuberaceae, thereby laying the groundwork for our understanding of the evolution, phylogeny, and population genetics of these important ectomycorrhizal fungi.


2019 ◽  
Vol 1 (2) ◽  
pp. Manuscript
Author(s):  
Kamarul Rahim Kamarudin ◽  
Maryam Mohamed Rehan ◽  
'Aisyah Mohamed Rehan

Species identification of sea cucumbers that have undergone body deformation due to extensive food processing e.g. beche-de-mer is difficult especially with the copresence of cases of unlabelled or mislabelled sea cucumber-based products in the markets.  Therefore, a study was done to determine the species identities of processed sea cucumbers from selected Malaysian markets using concatenated gene sequences of non-protein-coding 12S mitochondrial rRNA gene and non-protein-coding 16S mitochondrial rRNA gene. Phylogenetic analyses based on the distance-based Neighbour Joining method, and the character-based methods i.e. the Maximum Parsimony method, Maximum Likelihood method, and the Bayesian Analysis method of 47 ingroup sequences representing 37 processed sea cucumber specimens, six reference samples, and four additional specimens suggested the presence of three main clusters i.e. gamat family consisting of genus Stichopus and genus Thelenota; and timun laut family comprising family Holothuriidae. A number of three gamat species i.e. Stichopus horrens, Stichopus vastus, and Thelenota anax were recorded. Meanwhile, the specimens of Holothuria (Halodeima) atra, Holothuria (Halodeima) edulis, Holothuria (Metriatyla) lessoni, Holothuria (Mertensiothuria) leucospilota, and Holothuria (Metriatyla) scabra were the five timun laut species that grouped under the family Holothuriidae. The outcomes of this study can be utilised by the enforcement agencies to monitor and overcome the issues of species substitution and product mislabelling of processed sea cucumber products in Malaysian markets.


2011 ◽  
Vol 77 (6) ◽  
pp. 2071-2080 ◽  
Author(s):  
Bartholomeus van den Bogert ◽  
Willem M. de Vos ◽  
Erwin G. Zoetendal ◽  
Michiel Kleerebezem

ABSTRACTLarge-scale and in-depth characterization of the intestinal microbiota necessitates application of high-throughput 16S rRNA gene-based technologies, such as barcoded pyrosequencing and phylogenetic microarray analysis. In this study, the two techniques were compared and contrasted for analysis of the bacterial composition in three fecal and three small intestinal samples from human individuals. As PCR remains a crucial step in sample preparation for both techniques, different forward primers were used for amplification to assess their impact on microbial profiling results. An average of 7,944 pyrosequences, spanning the V1 and V2 region of 16S rRNA genes, was obtained per sample. Although primer choice in barcoded pyrosequencing did not affect species richness and diversity estimates, detection ofActinobacteriastrongly depended on the selected primer. Microbial profiles obtained by pyrosequencing and phylogenetic microarray analysis (HITChip) correlated strongly for fecal and ileal lumen samples but were less concordant for ileostomy effluent. Quantitative PCR was employed to investigate the deviations in profiling between pyrosequencing and HITChip analysis. Since cloning and sequencing of random 16S rRNA genes from ileostomy effluent confirmed the presence of novel intestinal phylotypes detected by pyrosequencing, especially those belonging to theVeillonellagroup, the divergence between pyrosequencing and the HITChip is likely due to the relatively low number of available 16S rRNA gene sequences of small intestinal origin in the DNA databases that were used for HITChip probe design. Overall, this study demonstrated that equivalent biological conclusions are obtained by high-throughput profiling of microbial communities, independent of technology or primer choice.


Genome ◽  
2012 ◽  
Vol 55 (3) ◽  
pp. 222-233 ◽  
Author(s):  
Natuo Kômoto ◽  
Kenji Yukuhiro ◽  
Shuichiro Tomita

Webspinners (order Embioptera) are polyneopteran insects characterized by enlarged foretarsi with silk glands, whose silk is used to produce galleries in which the insects live gregariously. The phylogenetic position of webspinners has been debated. In the present study, an almost complete mitochondrial DNA (mtDNA) sequence of Embioptera is reported for the first time. The mtDNA of a webspinner, Aposthonia japonica , has the 13 protein-coding genes (PCGs) generally found in metazoan mtDNA sequences. There is a translocation of a large region including atp6, atp8, cox3, nad3, and nad5 as well as a duplication of the 12S rRNA gene. The rearrangement does not seem to affect nucleotide composition, although amino acid composition in some parts of the mtDNA is biased compared with other Polyneoptera species. Based on phylogenetic analyses using nucleotide sequences of all PCGs concatenated with two rRNA genes and the amino acid sequences of all PCGs, A. japonica is sister to Verophasmatodea, a suborder of typical stick and leaf insects.


2021 ◽  
Vol 12 ◽  
Author(s):  
Suhyun Kim ◽  
Md. Rashedul Islam ◽  
Ilnam Kang ◽  
Jang-Cheon Cho

Although many culture-independent molecular analyses have elucidated a great diversity of freshwater bacterioplankton, the ecophysiological characteristics of several abundant freshwater bacterial groups are largely unknown due to the scarcity of cultured representatives. Therefore, a high-throughput dilution-to-extinction culturing (HTC) approach was implemented herein to enable the culture of these bacterioplankton lineages using water samples collected at various seasons and depths from Lake Soyang, an oligotrophic reservoir located in South Korea. Some predominant freshwater bacteria have been isolated from Lake Soyang via HTC (e.g., the acI lineage); however, large-scale HTC studies encompassing different seasons and water depths have not been documented yet. In this HTC approach, bacterial growth was detected in 14% of 5,376 inoculated wells. Further, phylogenetic analyses of 16S rRNA genes from a total of 605 putatively axenic bacterial cultures indicated that the HTC isolates were largely composed of Actinobacteria, Bacteroidetes, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. Importantly, the isolates were distributed across diverse taxa including phylogenetic lineages that are widely known cosmopolitan and representative freshwater bacterial groups such as the acI, acIV, LD28, FukuN57, MNG9, and TRA3–20 lineages. However, some abundant bacterial groups including the LD12 lineage, Chloroflexi, and Acidobacteria could not be domesticated. Among the 71 taxonomic groups in the HTC isolates, representative strains of 47 groups could either form colonies on agar plates or be revived from frozen glycerol stocks. Additionally, season and water depth significantly affected bacterial community structure, as demonstrated by 16S rRNA gene amplicon sequencing analyses. Therefore, our study successfully implemented a dilution-to-extinction cultivation strategy to cultivate previously uncultured or underrepresented freshwater bacterial groups, thus expanding the basis for future multi-omic studies.


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