scholarly journals Annotated Draft Genomes of Two Caddisfly Species Plectrocnemia conspersa CURTIS and Hydropsyche tenuis NAVAS (Insecta: Trichoptera)

2019 ◽  
Vol 11 (12) ◽  
pp. 3445-3451 ◽  
Author(s):  
Jacqueline Heckenhauer ◽  
Paul B Frandsen ◽  
Deepak K Gupta ◽  
Juraj Paule ◽  
Stefan Prost ◽  
...  
Keyword(s):  
De Novo ◽  
Low Cost ◽  
Gene Clusters ◽  
Genomic Region ◽  
Ecological Niches ◽  
Comparative Genomic ◽  
Insect Order ◽  
Wide Range ◽  
Sequencing Strategy ◽  
Genomic Studies

Abstract Members of the speciose insect order Trichoptera (caddisflies) provide important ecosystem services, for example, nutrient cycling through breaking down of organic matter. They are also of industrial interest due to their larval silk secretions. These form the basis for their diverse case-making behavior that allows them to exploit a wide range of ecological niches. Only five genomes of this order have been published thus far, with variable qualities regarding contiguity and completeness. A low-cost sequencing strategy, that is, using a single Oxford Nanopore flow cell per individual along with Illumina sequence reads was successfully used to generate high-quality genomes of two Trichoptera species, Plectrocnemia conspersa and Hydropsyche tenuis. Of the de novo assembly methods compared, assembly of low coverage Nanopore reads (∼18×) and subsequent polishing with long reads followed by Illumina short reads (∼80–170× coverage) yielded the highest genome quality both in terms of contiguity and BUSCO completeness. The presented genomes are the shortest to date and extend our knowledge of genome size across caddisfly families. The genomic region that encodes for light (L)-chain fibroin, a protein component of larval caddisfly silk was identified and compared with existing L-fibroin gene clusters. The new genomic resources presented in this paper are among the highest quality Trichoptera genomes and will increase the knowledge of this important insect order by serving as the basis for phylogenomic and comparative genomic studies.

scholarly journals High-Quality Genome Assembly of Peronospora destructor, the Causal Agent of Onion Downy Mildew

2020 ◽  
Vol 33 (5) ◽  
pp. 718-720
Author(s):  
Karthi Natesan ◽  
Ji Yeon Park ◽  
Cheol-Woo Kim ◽  
Dong Suk Park ◽  
Young-Seok Kwon ◽  
...  
Keyword(s):  
Downy Mildew ◽  
De Novo ◽  
Gc Content ◽  
Comparative Genomic ◽  
High Quality ◽  
Sequencing Platform ◽  
Peronospora Destructor ◽  
Genomic Studies ◽  
Genome Assemblies ◽  
High Quality Genome

Peronospora destructor is an obligate biotrophic oomycete that causes downy mildew on onion (Allium cepa). Onion is an important crop worldwide, but its production is affected by this pathogen. We sequenced the genome of P. destructor using the PacBio sequencing platform, and de novo assembly resulted in 74 contigs with a total contig size of 29.3 Mb and 48.48% GC content. Here, we report the first high-quality genome sequence of P. destructor and its comparison with the genome assemblies of other oomycetes. The genome is a very useful resource to serve as a reference for analysis of P. destructor isolates and for comparative genomic studies of the biotrophic oomycetes.

scholarly journals De Novo Assembly of the Northern Cardinal (Cardinalis cardinalis) Genome Reveals Candidate Regulatory Regions for Sexually Dichromatic Red Plumage Coloration

2020 ◽  
Vol 10 (10) ◽  
pp. 3541-3548
Author(s):  
Simon Yung Wa Sin ◽  
Lily Lu ◽  
Scott V. Edwards
Keyword(s):  
De Novo ◽  
Draft Genome ◽  
Single Copy ◽  
Genomic Region ◽  
Plumage Coloration ◽  
Sexual Dichromatism ◽  
Effective Population ◽  
Cardinalis Cardinalis ◽  
Northern Cardinal ◽  
Genomic Studies

Northern cardinals (Cardinalis cardinalis) are common, mid-sized passerines widely distributed in North America. As an iconic species with strong sexual dichromatism, it has been the focus of extensive ecological and evolutionary research, yet genomic studies investigating the evolution of genotype–phenotype association of plumage coloration and dichromatism are lacking. Here we present a new, highly-contiguous assembly for C. cardinalis. We generated a 1.1 Gb assembly comprised of 4,762 scaffolds, with a scaffold N50 of 3.6 Mb, a contig N50 of 114.4 kb and a longest scaffold of 19.7 Mb. We identified 93.5% complete and single-copy orthologs from an Aves dataset using BUSCO, demonstrating high completeness of the genome assembly. We annotated the genomic region comprising the CYP2J19 gene, which plays a pivotal role in the red coloration in birds. Comparative analyses demonstrated non-exonic regions unique to the CYP2J19 gene in passerines and a long insertion upstream of the gene in C. cardinalis. Transcription factor binding motifs discovered in the unique insertion region in C. cardinalis suggest potential androgen-regulated mechanisms underlying sexual dichromatism. Pairwise Sequential Markovian Coalescent (PSMC) analysis of the genome reveals fluctuations in historic effective population size between 100,000–250,000 in the last 2 millions years, with declines concordant with the beginning of the Pleistocene epoch and Last Glacial Period. This draft genome of C. cardinalis provides an important resource for future studies of ecological, evolutionary, and functional genomics in cardinals and other birds.

scholarly journals Genome assembly of the tayra (Eira barbara, Mustelidae) and comparative genomic analysis reveal adaptive genetic variation in the subfamily Guloninae

2021 ◽  
Author(s):  
Lorena Derežanin ◽  
Asta Blažytė ◽  
Pavel Dobrynin ◽  
David A. Duchêne ◽  
José H. Grau ◽  
...  
Keyword(s):  
Body Condition ◽  
De Novo ◽  
Species Traits ◽  
Ecological Niches ◽  
Comparative Genomic ◽  
Phenotypic Traits ◽  
Adaptive Genetic Variation ◽  
Eira Barbara ◽  
Species Specific ◽  
Candidate Loci

Species of the mustelid subfamily Guloninae inhabit diverse habitats on multiple continents, and occupy a variety of ecological niches. They differ in feeding ecologies, reproductive strategies and morphological adaptations. To identify candidate loci associated with adaptations to their respective environments, we generated a de novo assembly of the tayra (Eira barbara), the earliest diverging species in the subfamily, and compared this with the genomes available for the wolverine (Gulo gulo) and the sable (Martes zibellina). Our comparative genomic analyses included searching for signs of positive selection, examining changes in gene family sizes, as well as searching for species-specific structural variants (SVs). Among candidate loci that appear to be associated with phenotypic traits, we observed many genes related to diet, body condition and reproduction. For the tayra, which has an atypical gulonine reproductive strategy of aseasonal breeding, we observe species-specific changes in many pregnancy-related genes. For the wolverine, a circumpolar hypercarnivore that must cope with seasonal food scarcity, we observed many specific changes in genes associated with diet and body condition. Despite restricting some of our analyses to single-copy orthologs present in all three study species, we observed many candidate loci that may be linked to species traits related to environment-specific challenges in their respective habitats.

scholarly journals Odorant-binding proteins in canine anal sac glands indicate an evolutionarily conserved role in mammalian chemical communication

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sunita Janssenswillen ◽  
Kim Roelants ◽  
Sebastien Carpentier ◽  
Hilde de Rooster ◽  
Mieke Metzemaekers ◽  
...  
Keyword(s):  
Chemical Communication ◽  
Binding Proteins ◽  
Evolutionary Relationship ◽  
Gene Clusters ◽  
Pseudoautosomal Region ◽  
Comparative Genomic ◽  
Odorant Binding Proteins ◽  
Wide Range ◽  
Anal Sac ◽  
Odorant Binding

Abstract Background Chemical communication is an important aspect of the behavioural ecology of a wide range of mammals. In dogs and other carnivores, anal sac glands are thought to convey information to conspecifics by secreting a pallet of small volatile molecules produced by symbiotic bacteria. Because these glands are unique to carnivores, it is unclear how their secretions relate to those of other placental mammals that make use of different tissues and secretions for chemical communication. Here we analyse the anal sac glands of domestic dogs to verify the secretion of proteins and infer their evolutionary relationship to those involved in the chemical communication of non-carnivoran mammals. Results Proteomic analysis of anal sac gland secretions of 17 dogs revealed the consistently abundant presence of three related proteins. Homology searches against online databases indicate that these proteins are evolutionary related to ‘odorant binding proteins’ (OBPs) found in a wide range of mammalian secretions and known to contribute to chemical communication. Screening of the dog’s genome sequence show that the newly discovered OBPs are encoded by a single cluster of three genes in the pseudoautosomal region of the X-chromosome. Comparative genomic screening indicates that the same locus is shared by a wide range of placental mammals and that it originated at least before the radiation of extant placental orders. Phylogenetic analyses suggest a dynamic evolution of gene duplication and loss, resulting in large gene clusters in some placental taxa and recurrent loss of this locus in others. The homology of OBPs in canid anal sac glands and those found in other mammalian secretions implies that these proteins maintained a function in chemical communication throughout mammalian evolutionary history by multiple shifts in expression between secretory tissues involved in signal release and nasal mucosa involved in signal reception. Conclusions Our study elucidates a poorly understood part of the biology of a species that lives in close association with humans. In addition, it shows that the protein repertoire underlying chemical communication in mammals is more evolutionarily stable than the variation of involved glands and tissues would suggest.

scholarly journals Structural and functional characterization of a putative de novo gene in Drosophila

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andreas Lange ◽  
Prajal H. Patel ◽  
Brennen Heames ◽  
Adam M. Damry ◽  
Thorsten Saenger ◽  
...  
Keyword(s):  
De Novo ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Noncoding Dna ◽  
Protein Coding ◽  
Ancestral Sequences ◽  
De Novo Gene ◽  
Genomic Studies ◽  
Biochemical Genetic

AbstractComparative genomic studies have repeatedly shown that new protein-coding genes can emerge de novo from noncoding DNA. Still unknown is how and when the structures of encoded de novo proteins emerge and evolve. Combining biochemical, genetic and evolutionary analyses, we elucidate the function and structure of goddard, a gene which appears to have evolved de novo at least 50 million years ago within the Drosophila genus. Previous studies found that goddard is required for male fertility. Here, we show that Goddard protein localizes to elongating sperm axonemes and that in its absence, elongated spermatids fail to undergo individualization. Combining modelling, NMR and circular dichroism (CD) data, we show that Goddard protein contains a large central α-helix, but is otherwise partially disordered. We find similar results for Goddard’s orthologs from divergent fly species and their reconstructed ancestral sequences. Accordingly, Goddard’s structure appears to have been maintained with only minor changes over millions of years.

scholarly journals A High-Quality Genome Assembly of the North American Song Sparrow, Melospiza melodia

2020 ◽  
Vol 10 (4) ◽  
pp. 1159-1166 ◽  
Author(s):  
Swarnali Louha ◽  
David A. Ray ◽  
Kevin Winker ◽  
Travis C. Glenn
Keyword(s):  
Biomedical Research ◽  
Genome Assembly ◽  
De Novo ◽  
Genome Structure ◽  
Melospiza Melodia ◽  
Song Sparrow ◽  
Comparative Genomic ◽  
High Quality ◽  
Wide Range

The song sparrow, Melospiza melodia, is one of the most widely distributed species of songbirds found in North America. It has been used in a wide range of behavioral and ecological studies. This species’ pronounced morphological and behavioral diversity across populations makes it a favorable candidate in several areas of biomedical research. We have generated a high-quality de novo genome assembly of M. melodia using Illumina short read sequences from genomic and in vitro proximity-ligation libraries. The assembled genome is 978.3 Mb, with a physical coverage of 24.9×, N50 scaffold size of 5.6 Mb and N50 contig size of 31.7 Kb. Our genome assembly is highly complete, with 87.5% full-length genes present out of a set of 4,915 universal single-copy orthologs present in most avian genomes. We annotated our genome assembly and constructed 15,086 gene models, a majority of which have high homology to related birds, Taeniopygia guttata and Junco hyemalis. In total, 83% of the annotated genes are assigned with putative functions. Furthermore, only ∼7% of the genome is found to be repetitive; these regions and other non-coding functional regions are also identified. The high-quality M. melodia genome assembly and annotations we report will serve as a valuable resource for facilitating studies on genome structure and evolution that can contribute to biomedical research and serve as a reference in population genomic and comparative genomic studies of closely related species.

scholarly journals Comparative genome analyses of four rice-infecting Rhizoctonia solani isolates reveal extensive enrichment of homogalacturonan modification genes

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Da-Young Lee ◽  
Jongbum Jeon ◽  
Ki-Tae Kim ◽  
Kyeongchae Cheong ◽  
Hyeunjeong Song ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Single Molecule ◽  
De Novo ◽  
Average Length ◽  
Gene Clusters ◽  
Anastomosis Group ◽  
Secreted Proteins ◽  
Geographical Regions ◽  
Wide Range ◽  
Fungal Genomes

Abstract Background Plant pathogenic isolates of Rhizoctonia solani anastomosis group 1-intraspecific group IA (AG1-IA) infect a wide range of crops causing diseases such as rice sheath blight (ShB). ShB has become a serious disease in rice production worldwide. Additional genome sequences of the rice-infecting R. solani isolates from different geographical regions will facilitate the identification of important pathogenicity-related genes in the fungus. Results Rice-infecting R. solani isolates B2 (USA), ADB (India), WGL (India), and YN-7 (China) were selected for whole-genome sequencing. Single-Molecule Real-Time (SMRT) and Illumina sequencing were used for de novo sequencing of the B2 genome. The genomes of the other three isolates were then sequenced with Illumina technology and assembled using the B2 genome as a reference. The four genomes ranged from 38.9 to 45.0 Mbp in size, contained 9715 to 11,505 protein-coding genes, and shared 5812 conserved orthogroups. The proportion of transposable elements (TEs) and average length of TE sequences in the B2 genome was nearly 3 times and 2 times greater, respectively, than those of ADB, WGL and YN-7. Although 818 to 888 putative secreted proteins were identified in the four isolates, only 30% of them were predicted to be small secreted proteins, which is a smaller proportion than what is usually found in the genomes of cereal necrotrophic fungi. Despite a lack of putative secondary metabolite biosynthesis gene clusters, the rice-infecting R. solani genomes were predicted to contain the most carbohydrate-active enzyme (CAZyme) genes among all 27 fungal genomes used in the comparative analysis. Specifically, extensive enrichment of pectin/homogalacturonan modification genes were found in all four rice-infecting R. solani genomes. Conclusion Four R. solani genomes were sequenced, annotated, and compared to other fungal genomes to identify distinctive genomic features that may contribute to the pathogenicity of rice-infecting R. solani. Our analyses provided evidence that genomic conservation of R. solani genomes among neighboring AGs was more diversified than among AG1-IA isolates and the presence of numerous predicted pectin modification genes in the rice-infecting R. solani genomes that may contribute to the wide host range and virulence of this necrotrophic fungal pathogen.

scholarly journals Plasmids encode niche-specific traits in Lactobacillaceae

2020 ◽  
Author(s):  
Dimple Davray ◽  
Dipti Deo ◽  
Ram Kulkarni
Keyword(s):  
Gc Content ◽  
Nucleotide Sequences ◽  
Ecological Niches ◽  
Comparative Genomic ◽  
Fermented Foods ◽  
Probiotic Properties ◽  
Genome Sequences ◽  
Free Living ◽  
Wide Range ◽  
Living Species

AbstractThe species of family Lactobacillaceae are found in highly diverse environments and play an important role in fermented foods and probiotic products. Many of these species have been individually reported to harbor plasmids that encode important genes. In this study, we performed comparative genomic analysis of the publically available data of 512 plasmids from 282 strains represented by 51 species of this family and correlated the genomic features of plasmids with the ecological niches in which these species are found. Two-third of the species had at least one plasmid-harboring strain. Plasmid abundance and GC content were significantly lower in the vertebrate-adapted species as compared to the nomadic and free-living species. Hierarchical clustering (HCL) highlighted the distinct nature of plasmids from the nomadic and free-living species than those from the vertebrate-adapted species. EggNOG assisted functional annotation revealed that genes associated with transposition, conjugation, DNA repair and recombination, exopolysaccharide production, metal ion transport, toxin-antitoxin system, and stress tolerance were significantly enriched on the plasmids of the nomadic and in some cases nomadic and free-living species. On the other hand, genes related to anaerobic metabolism, ABC transporters, and major facilitator superfamily were found to be overrepresented on the plasmids of the vertebrate-adapted species. These genomic signatures are correlated to the comparatively nutrient-depleted, stressful and dynamic environments of nomadic and free-living species and nutrient-rich and anaerobic environments of the vertebrate-adapted species. Thus, these results indicate the contribution of the plasmids in the adaptation of lactobacilli to the respective habitats. This study also underlines the potential application of these plasmids in improving the technological and probiotic properties of lactic acid bacteria.Impact statementThe bacteria of the family Lactobacillaceae are present in the wide range of habitats and play an important role in human health, fermented foods and chemical industries. A few studies have demonstrated the presence of plasmids in the individual strains of Lactobacillaceae species encoding various traits. Extensive data of genome sequences of the lactobacilli are becoming available; however, no comprehensive analysis of the plasmid-encoded genes and determining their biological relevance across lactobacilli has been undertaken at a larger scale. In this study, we explored the genomic content of 512 plasmids of Lactobacillaceae species and correlated it to the three types of these species according to their ecological niches – vertebrate-adapted, free-living and nomadic. Comparatively lower plasmid abundance and GC content in the vertebrate-adapted species could be correlated to the presence of these species in the nutrient-rich environment. The genomic content of the plasmids was consistent with the respective lifestyle adopted by lactobacilli suggesting that the plasmids might enhance the niche-specific fitness of the strains. The plethora of important genes present on the plasmids can also make them a highly useful tool in improving the probiotic, technological and food-related properties of lactobacilli.Data summaryNucleotide sequences of plasmids of Lactobacillus strains for which complete genome sequences were available were retrieved from the NCBI genome [https://www.ncbi.nlm.nih.gov/genome] and PATRIC 3.5.41 databases on 31st March 2019. The dataset includes 512 nucleotide sequences of plasmids of 282 strains belonging to genus Lactobacillus before its reclassification into several genera (1). Details of the plasmids have been given in Table S1.

scholarly journals New Insights Into the Biosynthesis of Typical Bioactive Components in the Traditional Chinese Medicinal Fungus Cordyceps militaris

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiuyun Wu ◽  
Tao Wu ◽  
Ailin Huang ◽  
Yuanyuan Shen ◽  
Xuanyu Zhang ◽  
...  
Keyword(s):  
Low Cost ◽  
Gene Clusters ◽  
Cordyceps Militaris ◽  
Research Progress ◽  
Microbial Cell Factories ◽  
Medicinal Fungus ◽  
Cell Factories ◽  
Wide Range ◽  
History Of ◽  
Bioactive Ingredients

Cordyceps militaris, a traditional medicinal ingredient with a long history of application in China, is regarded as a high-value fungus due to its production of various bioactive ingredients with a wide range of pharmacological effects in clinical treatment. Several typical bioactive ingredients, such as cordycepin, D-mannitol, cordyceps polysaccharides, and N6-(2-hydroxyethyl)-adenosine (HEA), have received increasing attention due to their antitumor, antioxidant, antidiabetic, radioprotective, antiviral and immunomodulatory activities. Here, we systematically sorted out the latest research progress on the chemical characteristics, biosynthetic gene clusters and pathways of these four typical bioactive ingredients. This summary will lay a foundation for obtaining low-cost and high-quality bioactive ingredients in large amounts using microbial cell factories in the future.

scholarly journals Transporter Gene-mediated Typing for Detection and Genome Mining of Lipopeptide-producing Pseudomonas

2021 ◽  
Author(s):  
Léa Girard ◽  
Niels Geudens ◽  
Brent Pauwels ◽  
Monica Höfte ◽  
José C. Martins ◽  
...  
Keyword(s):  
Genome Mining ◽  
Chemical Characterization ◽  
Gene Clusters ◽  
Amplicon Sequencing ◽  
Chemical Diversity ◽  
Ecological Niches ◽  
Transporter Gene ◽  
A Genome ◽  
Wide Range ◽  
Suitable Target

Pseudomonas lipopeptides (LPs) are involved in diverse ecological functions and have biotechnological potential associated with their antimicrobial and/or anti-proliferative activities. They are synthesized by multi-modular non-ribosomal peptide synthetases which, together with transport and regulatory proteins, are encoded by large biosynthetic gene clusters (BGCs). These secondary metabolites are classified in distinct families based on sequence and length of the oligopeptide, and size of the macrocycle, if present. Phylogeny of PleB, the MacB-like transporter that is part of a dedicated ATP-dependent tripartite efflux system driving export of Pseudomonas LPs, revealed a strong correlation with LP chemical diversity. As each LP BGC carries its cognate pleB , PleB is suitable as a diagnostic sequence for genome mining, allowing assignment of the putative metabolite to a particular LP family. In addition, pleB proved a suitable target gene for an alternative PCR method to detect LP-producing Pseudomonas , not relying on amplification of catalytic domains of the biosynthetic enzymes. Combined with amplicon sequencing, this approach enabled typing of Pseudomonas strains as potential producers of a LP belonging to one of ten different families, underscoring its value for strain prioritization. This was validated by chemical characterization of known LPs from three different families secreted by novel producers isolated from the rice or maize rhizosphere, namely the type strains of Pseudomonas fulva (putisolvin), Pseudomonas zeae (tensin) and Pseudomonas xantholysinigenes (xantholysin). In addition, a new member of the Bananamide family, prosekin, was discovered in the type strain of Pseudomonas prosekii , an Antarctic isolate. Importance Pseudomonas are ubiquitous bacteria able to thrive in a wide range of ecological niches and lipopeptides often support their lifestyle but also their interaction with other micro- and macro-organisms. Therefore, the production of lipopeptides is widespread among Pseudomonas strains. Consequently, Pseudomonas lipopeptide research affects not only chemists and microbiologists but touches a much broader audience, including biochemists, ecologists and plant biologists. In this study we present a reliable transporter gene-guided approach for the detection and/or typing of Pseudomonas lipopeptide producers. Indeed, it allows to readily assess the lipopeptide diversity among sets of Pseudomonas isolates and differentiate strains likely to produce known lipopeptides from producers of potentially novel lipopeptides. This work provides a valuable tool that can also be integrated in a genome mining strategy and adapted for the typing of other specialized metabolites.

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