scholarly journals Exon-based phylogenomics strengthens the phylogeny of Neotropical cichlids and identifies remaining conflicting clades (Cichliformes: Cichlidae: Cichlinae)

2017 ◽  
Author(s):  
Katriina L. Ilves ◽  
Dax Torti ◽  
Hernán Lépez-Fernández
Keyword(s):  
Reference Genome ◽  
Single Copy ◽  
Species Trees ◽  
Ecological Processes ◽  
Cichlid Fishes ◽  
Sequence Capture ◽  
Reconstruction Methods ◽  
Complete Dataset ◽  
Generation Sequencing ◽  
Neotropical Cichlids

AbstractThe phenotypic, geographic, and species diversity of cichlid fishes have made them a group of great interest for studying evolutionary processes. Here we present a targeted-exon next-generation sequencing approach for investigating the evolutionary relationships of cichlid fishes (Cichlidae), with focus on the Neotropical subfamily Cichlinae using a set of 923 primarily single-copy exons designed through mining of the Nile tilapia (Oreochromis niloticus) genome. Sequence capture and assembly were robust, leading to a complete dataset of 415 exons for 139 species (147 terminals) that consisted of 128 Neotropical species, six African taxa, and five Indo-Malagasy cichlids. Gene and species trees were calculated using alternative partitioning schemes and reconstruction methods. In general, all methods yielded similar topologies to previously hypothesized relationships within the Cichlinae and clarified several relationships that were previously poorly supported or in conflict. Additional work will be needed to fully resolve all aspects of Cichlinae phylogeny. Overall, this approach yielded a well-resolved phylogeny of Neotropical cichlids that will be of utility for future assessments of the evolutionary and ecological processes within this diverse group of fishes. Furthermore, the general methodology employed here of exon targeting and capture should be applicable to any group of organisms with the availability of a reference genome.

scholarly journals Genome Assembly of the Canadian Two-row Malting Barley Cultivar AAC Synergy

2021 ◽  
Author(s):  
Wayne Xu ◽  
James R Tucker ◽  
Wubishet A Bekele ◽  
Frank M You ◽  
Yong-Bi Fu ◽  
...  
Keyword(s):  
Reference Genome ◽  
Single Copy ◽  
Barley Cultivar ◽  
Malting Barley ◽  
Orthologous Genes ◽  
Hordeum Vulgare L ◽  
Chromosome Conformation ◽  
Mate Pair ◽  
Genome Assemblies ◽  
First Time

Abstract Barley (Hordeum vulgare L.) is one of the most important global crops. The six-row barley cultivar Morex reference genome has been used by the barley research community worldwide. However, this reference genome can have limitations when used for genomic and genetic diversity analysis studies, gene discovery, and marker development when working in two-row germplasm that is more common to Canadian barley. Here we assembled, for the first time, the genome sequence of a Canadian two-row malting barley, cultivar AAC Synergy. We applied deep Illumina paired-end reads, long mate-pair reads, PacBio sequences, 10X chromium linked read libraries, and chromosome conformation capture sequencing (Hi-C) to generate a contiguous assembly. The genome assembled from super-scaffolds had a size of 4.85 Gb, N50 of 2.32 Mb and an estimated 93.9% of complete genes from a plant database (BUSCO, benchmarking universal single-copy orthologous genes). After removal of small scaffolds (< 300 Kb), the assembly was arranged into pseudomolecules of 4.14 Gb in size with seven chromosomes plus unanchored scaffolds. The completeness and annotation of the assembly were assessed by comparing it with the updated version of six-row Morex and recently released two-row Golden Promise genome assemblies.

scholarly journals Target sequence capture in orchids: Developing a kit to sequence hundreds of single‐copy loci

2021 ◽  
Author(s):  
Lauren A. Eserman ◽  
Shawn K. Thomas ◽  
Emily E. D. Coffey ◽  
James H. Leebens‐Mack
Keyword(s):  
Single Copy ◽  
Target Sequence ◽  
Sequence Capture

scholarly journals Next Generation Sequencing Approaches Deciphering Hidden Microbial Treasure in Soil

2021 ◽  
Vol 9 (3) ◽  
pp. 39-47
Author(s):  
Ruchi Srivastava ◽  
Keyword(s):  
Bacterial Species ◽  
Modern Concept ◽  
Soil Microbial Diversity ◽  
Ecological Processes ◽  
Human Capabilities ◽  
Soil Microbial ◽  
Functional Aspects ◽  
Initial Culture ◽  
Generation Sequencing ◽  
Culture Dependent

Soil is one of the most important and complex biological habitats on earth. As we know the microbes are important key players in every ecosystem, and biological and ecological processes. Thus, it is necessary to understand this microbial treasure to have information about their role in such processes. Initial culture dependent methods helped a lot but are insufficient to indentify all the microbial species present in the soil. It has been estimated that only ~1% of bacterial species are cultivable on culture medium and rest are still hidden in through such methods. On the other hands, soil metagenomics is a modern concept that allows us to recognize these hidden species without biasness of growing bacteria on to petri plates. In last two decades rapid improvements in modern techniques itself enhanced the human capabilities in not only identifying but also have an understanding of functional aspects of these microbes in soil. Present review describes the available culture dependent methods and emergence and improvement in modern sequencing approaches helping to explore soil microbial diversity of more detail.

scholarly journals Whole-genome assembly of Ganoderma leucocontextum (Ganodermataceae, Fungi) discovered from the Tibetan Plateau of China

2021 ◽  
Author(s):  
Yuanchao Liu ◽  
Longhua Huang ◽  
Huiping Hu ◽  
Manjun Cai ◽  
Xiaowei Liang ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Southwest China ◽  
Reference Genome ◽  
Biological Activities ◽  
Single Copy ◽  
The Tibetan Plateau ◽  
Whole Genome ◽  
High Quality ◽  
Pharmacological Activities ◽  
Genetic Studies

Abstract Ganoderma leucocontextum, a newly discovered species of Ganodermataceae in China, has diverse pharmacological activities. G. leucocontextum was widely cultivated in southwest China, but the systematic genetic study has been impeded by the lack of a reference genome. Herein, we present the first whole-genome assembly of G. leucocontextum based on the Illumina and Nanopore platform from high-quality DNA extracted from a monokaryon strain (DH-8). The generated genome was 50.05 Mb in size with a N50 scaffold size of 3.06 Mb, 78,206 coding sequences and 13,390 putative genes. Genome completeness was assessed using the Benchmarking Universal Single-Copy Orthologs (BUSCO) tool, which identified 96.55% of the 280 Fungi BUSCO genes. Furthermore, differences in functional genes of secondary metabolites (terpenoids) were analyzed between G. leucocontextum and G. lucidum. G. leucocontextum has more genes related to terpenoids synthesis compared to G. lucidum, which may be one of the reasons why they exhibit different biological activities. This is the first genome assembly and annotation for G. leucocontextum, which would enrich the toolbox for biological and genetic studies in G. leucocontextum.

scholarly journals De Novo Genome Assembly of a Foxtail Millet Cultivar Huagu11 Uncovered the Genetic Difference to the Cultivar Yugu1, and the Genetic Mechanism of Imazethapyr Tolerance

2021 ◽  
Author(s):  
Jie Wang ◽  
Shiming Li ◽  
Lei Lan ◽  
Mushan Xie ◽  
Shu Cheng ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Genome Sequence ◽  
Reference Genome ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Genome Comparison ◽  
Sequencing Technology ◽  
High Quality ◽  
Next Generation Sequencing Technology ◽  
Generation Sequencing

Abstract Background: Setaria italica is the second-most widely planted species of millets in the world and an important model grain crop for the research of C4 photosynthesis and abiotic stress tolerance. Through three genomes assembly and annotation efforts, all genomes were based on next generation sequencing technology, which limited the genome continuity. Results: Here we report a high-quality whole-genome of new cultivar Huagu11, using single-molecule real-time sequencing and High-throughput chromosome conformation capture (Hi-C) mapping technologies. The total assembly size of the Huagu11 genome was 408.37 Mb with a scaffold N50 size of 45.89 Mb. Compared with the other three reported millet genomes based on the next generation sequencing technology, the Huagu11 genome had the highest genomic continuity. Intraspecies comparison showed about 94.97% and 94.66% of the Yugu1 and Huagu11 genomes, respectively, were able to be aligned as one-to-one blocks with four chromosome inversion. The Huagu11 genome contained approximately 19.43 Mb Presence/absence Variation (PAV) with 627 protein-coding transcripts, while Yugu1 genomes had 20.53 Mb PAV sequences encoding 737 proteins. Overall, 969,596 Single-nucleotide polymorphism (SNPs) and 156,282 insertion-deletion (InDels) were identified between these two genomes. The genome comparison between Huagu11 and Yugu1 should reflect the genetic identity and variation between the cultivars of foxtail millet to a certain extent. The Ser-626-Aln substitution in acetohydroxy acid synthase (AHAS) was found to be relative to the imazethapyr tolerance in Huagu11. Conclusions: A new improved high-quality reference genome sequence of Setaria italica was assembled, and intraspecies genome comparison determined the genetic identity and variation between the cultivars of foxtail millet. Based on the genome sequence, it was found that the Ser-626-Aln substitution in AHAS was responsible for the imazethapyr tolerance in Huagu11. The new improved reference genome of Setaria italica will promote the genic and genomic studies of this species and be beneficial for cultivar improvement.

scholarly journals A systematic comparison of eight new plastome sequences from Ipomoea L

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6563
Author(s):  
Jianying Sun ◽  
Xiaofeng Dong ◽  
Qinghe Cao ◽  
Tao Xu ◽  
Mingku Zhu ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Next Generation Sequencing ◽  
Chloroplast Genome ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Single Copy ◽  
Next Generation ◽  
Variable Regions ◽  
Chloroplast Genomes ◽  
Generation Sequencing

Background Ipomoea is the largest genus in the family Convolvulaceae. The species in this genus have been widely used in many fields, such as agriculture, nutrition, and medicine. With the development of next-generation sequencing, more than 50 chloroplast genomes of Ipomoea species have been sequenced. However, the repeats and divergence regions in Ipomoea have not been well investigated. In the present study, we sequenced and assembled eight chloroplast genomes from sweet potato’s close wild relatives. By combining these with 32 published chloroplast genomes, we conducted a detailed comparative analysis of a broad range of Ipomoea species. Methods Eight chloroplast genomes were assembled using short DNA sequences generated by next-generation sequencing technology. By combining these chloroplast genomes with 32 other published Ipomoea chloroplast genomes downloaded from GenBank and the Oxford Research Archive, we conducted a comparative analysis of the repeat sequences and divergence regions across the Ipomoea genus. In addition, separate analyses of the Batatas group and Quamoclit group were also performed. Results The eight newly sequenced chloroplast genomes ranged from 161,225 to 161,721 bp in length and displayed the typical circular quadripartite structure, consisting of a pair of inverted repeat (IR) regions (30,798–30,910 bp each) separated by a large single copy (LSC) region (87,575–88,004 bp) and a small single copy (SSC) region (12,018–12,051 bp). The average guanine-cytosine (GC) content was approximately 40.5% in the IR region, 36.1% in the LSC region, 32.2% in the SSC regions, and 37.5% in complete sequence for all the generated plastomes. The eight chloroplast genome sequences from this study included 80 protein-coding genes, four rRNAs (rrn23, rrn16, rrn5, and rrn4.5), and 37 tRNAs. The boundaries of single copy regions and IR regions were highly conserved in the eight chloroplast genomes. In Ipomoea, 57–89 pairs of repetitive sequences and 39–64 simple sequence repeats were found. By conducting a sliding window analysis, we found six relatively high variable regions (ndhA intron, ndhH-ndhF, ndhF-rpl32, rpl32-trnL, rps16-trnQ, and ndhF) in the Ipomoea genus, eight (trnG, rpl32-trnL, ndhA intron, ndhF-rpl32, ndhH-ndhF, ccsA-ndhD, trnG-trnR, and pasA-ycf3) in the Batatas group, and eight (ndhA intron, petN-psbM, rpl32-trnL, trnG-trnR, trnK-rps16, ndhC-trnV, rps16-trnQ, and trnG) in the Quamoclit group. Our maximum-likelihood tree based on whole chloroplast genomes confirmed the phylogenetic topology reported in previous studies. Conclusions The chloroplast genome sequence and structure were highly conserved in the eight newly-sequenced Ipomoea species. Our comparative analysis included a broad range of Ipomoea chloroplast genomes, providing valuable information for Ipomoea species identification and enhancing the understanding of Ipomoea genetic resources.

scholarly journals benchNGS : An approach to benchmark short reads alignment tools

2015 ◽  
Author(s):  
Farzana Rahman ◽  
Mehedi Hassan ◽  
Alona Kryshchenko ◽  
Inna Dubchak ◽  
Tatiana V Tatarinova ◽  
...  
Keyword(s):  
Reference Genome ◽  
Global Alignment ◽  
Short Report ◽  
Related Genome ◽  
Genome Sequences ◽  
Short Reads ◽  
Relevant Reference ◽  
Next Generation Sequencing Ngs ◽  
Reference Genomes ◽  
Generation Sequencing

In the last decade a number of algorithms and associated software were developed to align next generation sequencing (NGS) reads to relevant reference genomes. The results of these programs may vary significantly, especially when the NGS reads are contain mutations not found in the reference genome. Yet there is no standard way to compare these programs and assess their biological relevance. We propose a benchmark to assess accuracy of the short reads mapping based on the pre-computed global alignment of closely related genome sequences. In this paper we outline the method and also present a short report of an experiment performed on five popular alignment tools .

scholarly journals Rapture-ready darters: choice of reference genome and genotyping method (whole-genome or sequence capture) influence population genomic inference in Etheostoma

2020 ◽  
Author(s):  
Brendan N. Reid ◽  
Rachel L. Moran ◽  
Christopher J. Kopack ◽  
Sarah W. Fitzpatrick
Keyword(s):  
Reference Genome ◽  
Sequence Data ◽  
Low Cost ◽  
Read Depth ◽  
Model Organisms ◽  
Whole Genome ◽  
Reduced Representation ◽  
Sequence Capture ◽  
Population Genomic ◽  
The Impact

AbstractResearchers studying non-model organisms have an increasing number of methods available for generating genomic data. However, the applicability of different methods across species, as well as the effect of reference genome choice on population genomic inference, are still difficult to predict in many cases. We evaluated the impact of data type (whole-genome vs. reduced representation) and reference genome choice on data quality and on population genomic and phylogenomic inference across several species of darters (subfamily Etheostomatinae), a highly diverse radiation of freshwater fish. We generated a high-quality reference genome and developed a hybrid RADseq/sequence capture (Rapture) protocol for the Arkansas darter (Etheostoma cragini). Rapture data from 1900 individuals spanning four darter species showed recovery of most loci across darter species at high depth and consistent estimates of heterozygosity regardless of reference genome choice. Loci with baits spanning both sides of the restriction enzyme cut site performed especially well across species. For low-coverage whole-genome data, choice of reference genome affected read depth and inferred heterozygosity. For similar amounts of sequence data, Rapture performed better at identifying fine-scale genetic structure compared to whole-genome sequencing. Rapture loci also recovered an accurate phylogeny for the study species and demonstrated high phylogenetic informativeness across the evolutionary history of the genus Etheostoma. Low cost and high cross-species effectiveness regardless of reference genome suggest that Rapture and similar sequence capture methods may be worthwhile choices for studies of diverse species radiations.

scholarly journals More than 1000 ultraconserved elements provide evidence that turtles are the sister group of archosaurs

2012 ◽  
Vol 8 (5) ◽  
pp. 783-786 ◽  
Author(s):  
Nicholas G. Crawford ◽  
Brant C. Faircloth ◽  
John E. McCormack ◽  
Robb T. Brumfield ◽  
Kevin Winker ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Common Ancestor ◽  
Sister Group ◽  
Single Copy ◽  
Recent Analysis ◽  
Phylogenetic Position ◽  
Ultraconserved Elements ◽  
Sequence Capture ◽  
Genomic Scale ◽  
Nuclear Loci

We present the first genomic-scale analysis addressing the phylogenetic position of turtles, using over 1000 loci from representatives of all major reptile lineages including tuatara. Previously, studies of morphological traits positioned turtles either at the base of the reptile tree or with lizards, snakes and tuatara (lepidosaurs), whereas molecular analyses typically allied turtles with crocodiles and birds (archosaurs). A recent analysis of shared microRNA families found that turtles are more closely related to lepidosaurs. To test this hypothesis with data from many single-copy nuclear loci dispersed throughout the genome, we used sequence capture, high-throughput sequencing and published genomes to obtain sequences from 1145 ultraconserved elements (UCEs) and their variable flanking DNA. The resulting phylogeny provides overwhelming support for the hypothesis that turtles evolved from a common ancestor of birds and crocodilians, rejecting the hypothesized relationship between turtles and lepidosaurs.

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