scholarly journals A guide to phylotranscriptomic analysis for phycologists

ALGAE ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 333-340
Author(s):  
Seongmin Cheon ◽  
Sung-Gwon Lee ◽  
Hyun-Hee Hong ◽  
Hyun-Gwan Lee ◽  
Kwang Young Kim ◽  
...  

Phylotranscriptomics is the study of phylogenetic relationships among taxa based on their DNA sequences derived from transcriptomes. Because of the relatively low cost of transcriptome sequencing compared with genome sequencing and the fact that phylotranscriptomics is almost as reliable as phylogenomics, the phylotranscriptomic analysis has recently emerged as the preferred method for studying evolutionary biology. However, it is challenging to perform transcriptomic and phylogenetic analyses together without programming expertise. This study presents a protocol for phylotranscriptomic analysis to aid marine biologists unfamiliar with UNIX command-line interface and bioinformatics tools. Here, we used transcriptomes to reconstruct a molecular phylogeny of dinoflagellate protists, a diverse and globally abundant group of marine plankton organisms whose large and complex genomic sequences have impeded conventional phylogenic analysis based on genomic data. We hope that our proposed protocol may serve as practical and helpful information for the training and education of novice phycologists.

2017 ◽  
Author(s):  
Raúl Amado Cattáneo ◽  
Luis Diambra ◽  
Andrés Norman McCarthy

Phylogenetics and population genetics are central disciplines in evolutionary biology. Both are based on the comparison of single DNA sequences, or a concatenation of a number of these. However, with the advent of next-generation DNA sequencing technologies, the approaches that consider large genomic data sets are of growing importance for the elucidation of evolutionary relationships among species. Among these approaches, the assembly and alignment-free methods which allow an efficient distance computation and phylogeny reconstruction are of great importance. However, it is not yet clear under what quality conditions and abundance of genomic data such methods are able to infer phylogenies accurately. In the present study we assess the method originally proposed by Fan et al. for whole genome data, in the elucidation of Tomatoes' chloroplast phylogenetics using short read sequences. We find that this assembly and alignment-free method is capable of reproducing previous results under conditions of high coverage, given that low frequency k-mers (i.e. error prone data) are effectively filter out. Finally, we present a complete chloroplast phylogeny for the best data quality candidates of the recently published 360 tomato genomes.


2017 ◽  
Author(s):  
Raúl Amado Cattáneo ◽  
Luis Diambra ◽  
Andrés Norman McCarthy

Phylogenetics and population genetics are central disciplines in evolutionary biology. Both are based on the comparison of single DNA sequences, or a concatenation of a number of these. However, with the advent of next-generation DNA sequencing technologies, the approaches that consider large genomic data sets are of growing importance for the elucidation of evolutionary relationships among species. Among these approaches, the assembly and alignment-free methods which allow an efficient distance computation and phylogeny reconstruction are of great importance. However, it is not yet clear under what quality conditions and abundance of genomic data such methods are able to infer phylogenies accurately. In the present study we assess the method originally proposed by Fan et al. for whole genome data, in the elucidation of Tomatoes' chloroplast phylogenetics using short read sequences. We find that this assembly and alignment-free method is capable of reproducing previous results under conditions of high coverage, given that low frequency k-mers (i.e. error prone data) are effectively filter out. Finally, we present a complete chloroplast phylogeny for the best data quality candidates of the recently published 360 tomato genomes.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2903
Author(s):  
Martin Ryberg

Phylogenetics is an intrinsic part of many analyses in evolutionary biology and ecology, and as the amount of data available for these analyses is increasing rapidly the need for automated pipelines to deal with the data also increases. Phylommand is a package of four programs to create, manipulate, and/or analyze phylogenetic trees or pairwise alignments. It is built to be easily implemented in software workflows, both directly on the command prompt, and executed using scripts. Inputs can be taken from standard input or a file, and the behavior of the programs can be changed through switches. By using standard file formats for phylogenetic analyses, such as newick, nexus, phylip, and fasta, phylommand is widely compatible with other software.


2019 ◽  
Vol 9 (10) ◽  
pp. 3101-3104 ◽  
Author(s):  
Johnathan Lo ◽  
Michelle M. Jonika ◽  
Heath Blackmon

Microsatellites are repetitive DNA sequences usually found in non-coding regions of the genome. Their quantification and analysis have applications in fields from population genetics to evolutionary biology. As genome assemblies become commonplace, the need for software that can facilitate analyses has never been greater. In particular, R packages that can analyze genomic data are particularly important since this is one of the most popular software environments for biologists. We created an R package, micRocounter, to quantify microsatellites. We have optimized our package for speed, accessibility, and portability, making the automated analysis of large genomic data sets feasible. Computationally intensive algorithms were built in C++ to increase speed. Tests using benchmark datasets show a 200-fold improvement in speed over existing software. A moderately sized genome of 500 Mb can be processed in under 50 sec. Results are output as an object in R increasing accessibility and flexibility for practitioners.


BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.


Botany ◽  
2014 ◽  
Vol 92 (12) ◽  
pp. 901-910 ◽  
Author(s):  
Joel P. Olfelt ◽  
William A. Freyman

Taxa of Rhodiola L. (Crassulaceae) generally grow in arctic or alpine habitats. Some Rhodiola species are used medicinally, one taxon, Rhodiola integrifolia Raf. subsp. leedyi (Rosend. & J.W.Moore) Moran, (Leedy’s roseroot), is rare and endangered, and the group’s biogeography in North America is intriguing because of distributional disjunctions and the possibility that Rhodiola rhodantha (A.Gray) H.Jacobsen (2n = 7II) and Rhodiola rosea L. (2n = 11II) hybridized to form Rhodiola integrifolia Raf. (2n = 18II). Recent studies of the North American Rhodiola suggest that the group’s current taxonomy is misleading. We analyzed nuclear and chloroplast DNA sequences (internal transcribed spacer (ITS), trnL intron, trnL–trnF spacer, trnS–trnG spacer) from the North American Rhodiola taxa. We combined our data with GenBank sequences from Asian Rhodiola species, performed parsimony, maximum likelihood (ML), and Bayesian phylogenetic analyses, and applied a Bayesian clock model to the ITS data. Our analyses reveal two major Rhodiola clades, suggest that hybridization between R. rhodantha and R. rosea lineages was possible, show two distinct clades within R. integrifolia, and demonstrate that a Black Hills, South Dakota, Rhodiola population should be reclassified as Leedy’s roseroot. We recommend that R. integrifolia be revised, and that the Black Hills Leedy’s roseroot population be managed as part of that rare and endangered taxon.


Zootaxa ◽  
2018 ◽  
Vol 4415 (1) ◽  
pp. 45 ◽  
Author(s):  
PIOTR GĄSIOREK ◽  
DANIEL STEC ◽  
WITOLD MOREK ◽  
ŁUKASZ MICHALCZYK

A laboratory strain identified as “Hypsibius dujardini” is one of the best studied tardigrade strains: it is widely used as a model organism in a variety of research projects, ranging from developmental and evolutionary biology through physiology and anatomy to astrobiology. Hypsibius dujardini, originally described from the Île-de-France by Doyère in the first half of the 19th century, is now the nominal species for the superfamily Hypsibioidea. The species was traditionally considered cosmopolitan despite the fact that insufficient, old and sometimes contradictory descriptions and records prevented adequate delineations of similar Hypsibius species. As a consequence, H. dujardini appeared to occur globally, from Norway to Samoa. In this paper, we provide the first integrated taxonomic redescription of H. dujardini. In addition to classic imaging by light microscopy and a comprehensive morphometric dataset, we present scanning electron photomicrographs, and DNA sequences for three nuclear markers (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial marker (COI) that are characterised by various mutation rates. The results of our study reveal that a commercially available strain that is maintained in many laboratories throughout the world, and assumed to represent H. dujardini sensu stricto, represents, in fact, a new species: H. exemplaris sp. nov. Redescribing the nominal taxon for Hypsibiidae, we also redefine the family and amend the definitions of the subfamily Hypsibiinae and the genus Hypsibius. Moreover, we transfer H. arcticus (Murray, 1907) and Hypsibius conifer Mihelčič, 1938 to the genus Ramazzottius since the species exhibit claws and eggs of the Ramazzottius type. Finally, we designate H. fuhrmanni as subjectively invalid because the extremely poor description precludes identifying neotype material. 


1994 ◽  
Vol 05 (05) ◽  
pp. 805-809 ◽  
Author(s):  
SALIM G. ANSARI ◽  
PAOLO GIOMMI ◽  
ALBERTO MICOL

On 3rd November, 1993, ESIS announced its Homepage on the World Wide Web (WWW) to the user community. Ever since then, ESIS has steadily increased its Web support to the astronomical community to include a bibliographic service, the ESIS catalogue documentation and the ESIS Data Browser. More functionality will be added in the near future. All these services share a common ESIS structure that is used by other ESIS user paradigms such as the ESIS Graphical User Interface (Giommi and Ansari, 1993), and the ESIS Command Line Interface. A forms-based paradigm, each ESIS-Web application interfaces to the hypertext transfer protocol (http) translating queries from/to the hypertext markup language (html) format understood by the NCSA Mosaic interface. In this paper, we discuss the ESIS system and show how each ESIS service works on the World Wide Web client.


Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.


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