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Asset Tag: Whole Genome Sequencing,

April 21, 2020

A Chromosome-Scale Genome Assembly of Paper Mulberry (Broussonetia papyrifera) Provides New Insights into Its Forage and Papermaking Usage.

Paper mulberry (Broussonetia papyrifera) is a well-known woody tree historically used for Cai Lun papermaking, one of the four great inventions of ancient China. More recently, Paper mulberry has also been used as forage to address the shortage of feedstuff because of its digestible crude fiber and high protein contents. In this study, we obtained a chromosome-scale genome assembly for Paper mulberry using integrated approaches, including Illumina and PacBio sequencing platform as well as Hi-C, optical, and genetic maps. The assembled Paper mulberry genome consists of 386.83 Mb, which is close to the estimated size, and 99.25% (383.93 Mb) of the assembly was assigned to 13 pseudochromosomes. Comparative genomic analysis revealed the expansion and contraction in the flavonoid and lignin biosynthetic gene families, respectively, accounting for the enhanced flavonoid and decreased lignin biosynthesis in Paper mulberry. Moreover, the increased ratio of syringyl-lignin to guaiacyl-lignin in Paper mulberry underscores its suitability for use in medicine, forage, papermaking, and barkcloth making. We also identified the root-associated microbiota of Paper mulberry and found that Pseudomonas and Rhizobia were enriched in its roots and may provide the source of nitrogen for its stems and leaves via symbiotic nitrogen fixation. Collectively, these results suggest that Paper mulberry might have undergone adaptive evolution and recruited nitrogen-fixing microbes to promote growth by enhancing flavonoid production and altering lignin monomer composition. Our study provides significant insights into genetic basis of the usefulness of Paper mulberry in papermaking and barkcloth making, and as forage. These insights will facilitate further domestication and selection as well as industrial utilization of Paper mulberry worldwide.Copyright © 2019 The Author. Published by Elsevier Inc. All rights reserved.

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April 21, 2020

Rapid Gene Cloning in Wheat

The identification of wheat and barley genes controlling important agronomic traits using positional cloning has traditionally been a challenging and time-consuming procedure. This is due to the enormous genome size and high repeat content from transposable elements (TEs). Low marker density, suppressed recombination, and the high cost of generating a physical contig across a genetically defined map interval have further restricted the application of positional approximation. Over the past decade, the cost of DNA sequencing has significantly dropped, as has our ability to computationally analyze large quantities of DNA sequence data. This has enabled researchers to exploit next-generation sequencing (NGS) technologies more routinely to accelerate the gene cloning process. In this chapter, we discuss several newly emerging cloning methods that combine NGS technologies with recent advances in molecular genomics to overcome previous limitations of gene cloning in wheat and barley.

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April 21, 2020

Inter-chromosomal coupling between vision and pigmentation genes during genomic divergence.

Recombination between loci underlying mate choice and ecological traits is a major evolutionary force acting against speciation with gene flow. The evolution of linkage disequilibrium between such loci is therefore a fundamental step in the origin of species. Here, we show that this process can take place in the absence of physical linkage in hamlets-a group of closely related reef fishes from the wider Caribbean that differ essentially in colour pattern and are reproductively isolated through strong visually-based assortative mating. Using full-genome analysis, we identify four narrow genomic intervals that are consistently differentiated among sympatric species in a backdrop of extremely low genomic divergence. These four intervals include genes involved in pigmentation (sox10), axial patterning (hoxc13a), photoreceptor development (casz1) and visual sensitivity (SWS and LWS opsins) that develop islands of long-distance and inter-chromosomal linkage disequilibrium as species diverge. The relatively simple genomic architecture of species differences facilitates the evolution of linkage disequilibrium in the presence of gene flow.

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April 21, 2020

Complete genome sequence of Euzebya sp. DY32-46, a marine Actinobacteria isolated from the Pacific Ocean

Euzebya sp. DY32-46 was isolated from seawater collected at the depth of 150?m in the eastern Pacific Ocean. The genome was sequenced and consisted of one chromosome and one plasmid pEDY32-46I with sizes of 5,799,875 and 571,580?bp as well as DNA G?+?C contents of 70.7 and 69.6%, respectively. Genomic annotation showed that fifty biosynthetic gene clusters of secondary metabolites were located in the chromosome of Euzebya sp. DY32-46, indicating that a wide variety of its natural products need to be explored. Besides, dozens of biogeochemically relevant genes found in the genome of Euzebya sp. DY32-46 revealed its ecological roles in marine carbon, nitrogen, phosphorus and sulfur cycles including transporting ammonium, phosphate and methylammonium, cleaving dimethylsulfoniopropionate and phosphate, reducing nitrite, etc. Based on genomic similarity analysis, Euzebya sp. DY32-46 represents a novel genospecies of the genus Euzebya, with average nucleotide identity and digital DNA-DNA hybridization values of 73.1-87.1% and 20.2-32.4% compared with the closely related type strains Euzebya rosea DSW09T and E. tangerina F10T. Comparative genomic analysis revealed that 97.1% of coding sequences were exclusively present in the plasmid pEDY32-46I contributing the speciation of Euzebya sp. DY32-46. This study widens our knowledge about industrial potential as well as ecological roles of the genus Euzebya and provides a great candidate for investigating nascent speciation of marine Actinobacteria.

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April 21, 2020

Complete genome sequences of a H2O2-resistant psychrophilic bacterium Colwellia sp. Arc7-D isolated from Arctic Ocean sediment

Colwellia sp. Arc7-D, a psychrophilic H2O2-resisitant bacterium, was isolated from Arctic Ocean sediment. Here we describe the complete genome of Colwellia sp. Arc7-D. The genome has one circular chromosome of 4,305,442?bp (37.67?mol%?G?+?C content), consisting of 3526 coding genes, 77 tRNA genes, as well as five rRNA operons as 16S–23S-5S rRNA and one rRNA operon as 16S-23S-5S-5S. According to KEGG analysis, strain Arc7-D encodes 23 genes related with antioxidant activity including superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase. However, many additional genes affiliated with anti-oxidative stress were also identified, such as aconitase, thioredoxin and ascorbic acid.

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April 21, 2020

Genomic and Functional Characterization of the Endophytic Bacillus subtilis 7PJ-16 Strain, a Potential Biocontrol Agent of Mulberry Fruit Sclerotiniose.

Bacillus sp. 7PJ-16, an endophytic bacterium isolated from a healthy mulberry stem and previously identified as Bacillus tequilensis 7PJ-16, exhibits strong antifungal activity and has the capacity to promote plant growth. This strain was studied for its effectiveness as a biocontrol agent to reduce mulberry fruit sclerotiniose in the field and as a growth-promoting agent for mulberry in the greenhouse. In field studies, the cell suspension and supernatant of strain 7PJ-16 exhibited biocontrol efficacy and the lowest disease incidence was reduced down to only 0.80%. In greenhouse experiments, the cell suspension (1.0?×?106 and 1.0?×?105 CFU/mL) and the cell-free supernatant (100-fold and 1000-fold dilution) stimulated mulberry seed germination and promoted mulberry seedling growth. In addition, to accurately identify the 7PJ-16 strain and further explore the mechanisms of its antifungal and growth-promoting properties, the complete genome of this strain was sequenced and annotated. The 7PJ-16 genome is comprised of two circular plasmids and a 4,209,045-bp circular chromosome, containing 4492 protein-coding genes and 116 RNA genes. This strain was ultimately designed as Bacillus subtilis based on core genome sequence analyses using a phylogenomic approach. In this genome, we identified a series of gene clusters that function in the synthesis of non-ribosomal peptides (surfactin, fengycin, bacillibactin, and bacilysin) as well as the ribosome-dependent synthesis of tasA and bacteriocins (subtilin, subtilosin A), which are responsible for the biosynthesis of numerous antimicrobial metabolites. Additionally, several genes with function that promote plant growth, such as indole-3-acetic acid biosynthesis, the production of volatile substances, and siderophores synthesis, were also identified. The information described in this study has established a good foundation for understanding the beneficial interactions between endophytes and host plants, and facilitates the further application of B. subtilis 7PJ-16 as an agricultural biofertilizer and biocontrol agent.

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April 21, 2020

Genetic Variation, Comparative Genomics, and the Diagnosis of Disease.

The discovery of mutations associated with human genetic dis- ease is an exercise in comparative genomics (see Glossary). Although there are many different strategies and approaches, the central premise is that affected persons harbor a significant excess of pathogenic DNA variants as com- pared with a group of unaffected persons (controls) that is either clinically defined1 or established by surveying large swaths of the general population.2 The more exclu- sive the variant is to the disease, the greater its penetrance, the larger its effect size, and the more relevant it becomes to both disease diagnosis and future therapeutic investigation. The most popular approach used by researchers in human genetics is the case–control design, but there are others that can be used to track variants and disease in a family context or that consider the probability of different classes of mutations based on evolutionary patterns of divergence or de novo mutational change.3,4 Although the approaches may be straightforward, the discovery of patho- genic variation and its mechanism of action often is less trivial, and decades of research can be required in order to identify the variants underlying both mendelian and complex genetic traits.

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April 21, 2020

Genome and transcriptome analyses of Leishmania spp.: opening Pandora’s box.

In the last 30 years, significant advances in genetic manipulation tools along with complete genome and transcriptome sequencing have advanced our understanding of the biology of Leishmania parasites and their interplay with the sand fly and mammalian hosts. High-throughput sequencing in association with CRISPR/Cas9 have prepared the ground for significant advances. Given the richness of the progress made over the last decade, in this article, we focused on the most recent contributions of genome-wide and transcriptome analyses of Leishmania spp., which permit the comparison of life cycle stages, the evaluation of different strains and species in their natural niches and in the field and the simultaneously comparison of the gene expression profiles of parasites and hosts.Copyright © 2019. Published by Elsevier Ltd.

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April 21, 2020

Mucilaginibacter xinganensis sp. nov., a phenanthrene-degrading bacterium isolated from wetland soil.

An aerobic, Gram-stain negative, rod-shaped and non-motile strain, BJC16-A31T, was isolated from the wetland soil sample taken from Daxing’anling, Heilongjiang, People’s Republic of China. Strain BJC16-A31T was found to be oxidase- and catalase-positive, and produced light orange colonies on modified R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BJC16-A31T is closely related to Mucilaginibacter gotjawali SA3-7T with 96.54% sequence similarity and it formed a separate lineage in the genus Mucilaginibacter. Strain BJC16-A31T contained menaquinone-7 (MK-7) as the predominant isoprenoid quinine. Anteiso-C15:0, C16:0 and anteiso-C15:0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, six unidentified polar lipid, two unidentified aminophospholipids and one unidentified aminolipid. The genome is composed of a circular 5,301,339 bp chromosome with average G?+?C percentage of 42.25%. The Average Nucleotide Identity (ANI) between strain BJC16-A31T and M. gotjawali SA3-7T was 77.51%. Combined phenotypic, chemotaxonomic, phylogenetic and genomic characteristics support the conclusion that strain BJC16-A31T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter xinganensis sp. nov. is proposed. The type strain is BJC16-A31T (=?CGMCC 1.12728T?=?NBRC 110384T).

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April 21, 2020

Multi-omics response of Pannonibacter phragmitetus BB to hexavalent chromium.

The release of hexavalent chromium [Cr(VI)] into water bodies poses a major threat to the environment and human health. However, studies of the biological response to Cr(VI) are limited. In this study, a toxic bacterial mechanism of Cr(VI) was investigated using Pannonibacter phragmitetus BB (hereafter BB), which was isolated from chromate slag. The maximum Cr(VI) concentrations with respect to the resistance and reduction by BB are 4000?mg?L-1 and 2500?mg?L-1, respectively. In the BB genome, more genes responsible for Cr(VI) resistance and reduction are observed compared with other P. phragmitetus strains. A total of 361 proteins were upregulated to respond to Cr(VI) exposure, including enzymes for Cr(VI) uptake, intracellular reduction, ROS detoxification, DNA repair, and Cr(VI) efflux and proteins associated with novel mechanisms involving extracellular reduction mediated by electron transfer, quorum sensing, and chemotaxis. Based on metabolomic analysis, 174 metabolites were identified. Most of the upregulated metabolites are involved in amino acid, glucose, lipid, and energy metabolisms. The results show that Cr(VI) induces metabolite production, while metabolites promote Cr(VI) reduction. Overall, multi-enzyme expression and metabolite production by BB contribute to its high ability to resist/reduce Cr(VI). This study provides details supporting the theory of Cr(VI) reduction and a theoretical basis for the efficient bioremoval of Cr(VI) from the environment. Copyright © 2019 Elsevier Ltd. All rights reserved.

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April 21, 2020

Stout camphor tree genome fills gaps in understanding of flowering plant genome evolution.

We present reference-quality genome assembly and annotation for the stout camphor tree (Cinnamomum kanehirae (Laurales, Lauraceae)), the first sequenced member of the Magnoliidae comprising four orders (Laurales, Magnoliales, Canellales and Piperales) and over 9,000 species. Phylogenomic analysis of 13 representative seed plant genomes indicates that magnoliid and eudicot lineages share more recent common ancestry than monocots. Two whole-genome duplication events were inferred within the magnoliid lineage: one before divergence of Laurales and Magnoliales and the other within the Lauraceae. Small-scale segmental duplications and tandem duplications also contributed to innovation in the evolutionary history of Cinnamomum. For example, expansion of the terpenoid synthase gene subfamilies within the Laurales spawned the diversity of Cinnamomum monoterpenes and sesquiterpenes.

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April 21, 2020

Population Genomic Analysis and De Novo Assembly Reveal the Origin of Weedy Rice as an Evolutionary Game.

Crop weediness, especially that of weedy rice (Oryza sativa f. spontanea), remains mysterious. Weedy rice possesses robust ecological adaptability; however, how this strain originated and gradually formed proprietary genetic features remains unclear. Here, we demonstrate that weedy rice at Asian high latitudes (WRAH) is phylogenetically well defined and possesses unselected genomic characteristics in many divergence regions between weedy and cultivated rice. We also identified novel quantitative trait loci underlying weedy-specific traits, and revealed that a genome block on the end of chromosome 1 is associated with rice weediness. To identify the genomic modifications underlying weedy rice evolution, we generated the first de novo assembly of a high-quality weedy rice genome (WR04-6), and conducted a comparative genomics study between WR04-6 with other rice reference genomes. Multiple lines of evidence, including the results of demographic scenario comparisons, suggest that differentiation between weedy rice and cultivated rice was initiated by genetic improvement of cultivated rice and that the essence of weediness arose through semi-domestication. A plant height model further implied that the origin of WRAH can be modeled as an evolutionary game and indicated that strategy-based selection driven by fitness shaped its genomic diversity.Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.

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April 21, 2020

Complete genome sequence of Bradymonas sediminis FA350T, the first representative of the order Bradymonadales

Bradymonas sediminis FA350T (=DSM 28820T?=?CICC 10904T) is a Gram-negative, rod-shaped and facultatively anaerobic bacterium isolated from coastal sediments from the Xiaoshi Island, Weihai, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that that strain FA350T belonged to a novel bacterial order in the class Deltaproteobacteria. Then, based on polyphasic taxonomy analyses, a novel order Bradymonadales and a novel family Bradymonadaceae were proposed and validly published. Here, we reported the complete genome of this strain; the genome is 5,045,683?bp in size, has a GC content of 61.1% and contains 3992 predicted genes. Strain FA350T featured being able to prey on bacteria like the members from the order Myxococcales. This is in concordance with the fact that strain FA350T encoded genes affiliated with ABC-transporter, type IV pilus, type II secretion system, toxins and chemotaxis, which are known to play critical roles in bacterial predation. This genome data will provide insights into the bacterial predation pattern of strain FA350T and facilitate the investigation of the mutual interaction between predators and prey. Nucleotide sequence accession number The complete genome sequence of B. sediminis FA350T is available in the NCBI database (accession number CP030032). The strain has been deposited in the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture and China Centre of Industrial Culture Collection (=DSM 28820T?=?CICC 10904T).

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April 21, 2020

First report of isolation and complete genome of Vibrio rotiferianus strain SSVR1601 from cage-cultured black rockfish (Sebastes schlegelii) associated with skin ulcer.

Vibrio rotiferianus is an important marine pathogen of various aquatic organisms and can be found widely distributed in the marine environment. To further characterize this pathogen, the pathogenic properties and genome of V. rotiferianus SSVR1601 isolated from Sebastes schlegelii with skin ulcer were analysed. SSVR1601 was shown to be short rod-shaped cell with a single polar flagellum. Different degrees of pathological changes in fish kidney, intestine, gills and liver were observed after SSVR1601 challenge. The SSVR1601 genome consists of two chromosomes and two plasmids with a total of 5,717,113 bp, 42.04%-44.93% GC content, 5,269 predicted CDSs, 134 tRNAs and 40 rRNAs. The common virulence factors including OMPs, haemolysin, flagellin, DNase, entF, algU, tcpI, acfB and rfaD were found in strain SSVR1601. Furthermore, factors responsible for iron uptake (fur, fepC and ccmC) and types II, IV and VI secretion systems were detected, which are likely responsible for the pathogenicity of SSVR1601. The antimicrobial resistance genes, bacA, tet34 and norM, were detected based on Antibiotic Resistance Genes Database. The phylogenetic analysis revealed SSVR1601 to be most closely related to V. rotiferianus strains CAIM577 and B64D1. © 2019 John Wiley & Sons Ltd.

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April 21, 2020

Genome sequence and characterization of the bcs clusters for the production of nanocellulose from the low pH resistant strain Komagataeibacter medellinensis ID13488.

Komagataeibacter medellinensis ID13488 (formerly Gluconacetobacter medellinensis ID13488) is able to produce crystalline bacterial cellulose (BC) under high acidic growth conditions. These abilities make this strain desirable for industrial BC production from acidic residues (e.g. wastes generated from cider production). To explore the molecular bases of the BC biosynthesis in this bacterium, the genome has been sequenced revealing a sequence of 3.4 Mb containing three putative plasmids of 38.1 kb (pKM01), 4.3 kb (pKM02) and 3.3 Kb (pKM03). Genome comparison analyses of K. medellinensis ID13488 with other cellulose-producing related strains resulted in the identification of the bcs genes involved in the cellulose biosynthesis. Genes arrangement and composition of four bcs clusters (bcs1, bcs2, bcs3 and bcs4) was studied by RT-PCR, and their organization in four operons transcribed as four independent polycistronic mRNAs was determined. qRT-PCR experiments demonstrated that mostly bcs1 and bcs4 are expressed under BC production conditions, suggesting that these operons direct the synthesis of BC. Genomic differences with the close related strain K. medellinensis NBRC 3288 unable to produce BC were also described and discussed. © 2019 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

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