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July 7, 2019

Complete genome sequence of Piscirickettsia salmonis LF-89 (ATCC VR-1361) a major pathogen of farmed salmonid fish.

Piscirickettsia salmonis, the causative agent of salmonid rickettsial septicemia (SRS), is a significant threat to the healthy and sustainable production of salmonid farming industry. This Gram-negative bacterium, originally isolated from a coho salmon in Southern Chile, produces a systemic infection characterized by colonization of several fish organs. P. salmonis is able to infect, survive, and replicate inside salmonid macrophages however little is known about its mechanisms of pathogenesis. Here, we present the whole genome sequence and annotation of the P. salmonis reference strain LF-89 (ATCC VR-1361). The genome contains one circular chromosome of 3,184,851bp and three plasmids, pPSLF89-1 (180,124bp), pPSLF89-2 (33,516bp) and pPSLF89-3 (51,573bp). A total of 2850 protein-coding genes, 56 tRNAs and six copies of 5S-16S-23S rRNA. Copyright © 2015 Elsevier B.V. All rights reserved.


July 7, 2019

The assembly and characterisation of two structurally distinct cattle MHC class I haplotypes point to the mechanisms driving diversity.

In cattle, there are six classical MHC class I genes that are variably present between different haplotypes. Almost all known haplotypes contain between one and three genes, with an allele of Gene 2 present on the vast majority. However, very little is known about the sequence and therefore structure and evolutionary history of this genomic region. To address this, we have refined the MHC class I region in the Hereford cattle genome assembly and sequenced a complete A14 haplotype from a homozygous Holstein. Comparison of the two haplotypes revealed extensive variation within the MHC class Ia region, but not within the flanking regions, with each gene contained within a conserved 63- to 68-kb sequence block. This variable region appears to have undergone block gene duplication and likely deletion at regular breakpoints, suggestive of a site-specific mechanism. Phylogenetic analysis using complete gene sequences provided evidence of allelic diversification via gene conversion, with breakpoints between each of the extracellular domains that were associated with high guanine-cytosine (GC) content. Advancing our knowledge of cattle MHC class I evolution will help inform investigations of cattle genetic diversity and disease resistance.


July 7, 2019

Draft genome sequence of Streptomyces sp. strain Wb2n-11, a desert isolate with broad-spectrum antagonism against soilborne phytopathogens.

Streptomyces sp. strain Wb2n-11, isolated from native desert soil, exhibited broad-spectrum antagonism against plant pathogenic fungi, bacteria, and nematodes. The 8.2-Mb draft genome reveals genes putatively responsible for its promising biocontrol activity and genes which enable the soil bacterium to directly interact beneficially with plants. Copyright © 2015 Köberl et al.


July 7, 2019

Acetylcholinesterase 1 in populations of organophosphate-resistant North American strains of the cattle tick, Rhipicephalus microplus (Acari: Ixodidae).

Rhipicephalus microplus, the cattle fever tick, is a global economic problem to the cattle industry due to direct infestation of cattle and pathogens transmitted during feeding. Cattle fever tick outbreaks continue to occur along the Mexico-US border even though the tick has been eradicated from the USA. The organophosphate (OP) coumaphos targets acetylcholinesterase (AChE) and is the approved acaricide for eradicating cattle fever tick outbreaks. There is evidence for coumaphos resistance developing in cattle ticks in Mexico, and OP-resistant R. microplus ticks were discovered in outbreak populations of Texas in 2005. The molecular basis of coumaphos resistance is not known, and our study was established to gather further information on whether AChE1 is involved in the resistance mechanism. We also sought information on allele diversity in tick populations with different levels of coumaphos resistance. The overarching project goal was to define OP resistance-associated gene mutations such that a DNA-based diagnostic assay could be developed to assist the management of resistance. Three different AChE transcripts have been reported in R. microplus, and supporting genomic and transcriptomic data are available at CattleTickBase. Here, we report the complete R. microplus AChE1 gene ascertained by sequencing a bacterial artificial chromosome clone containing the entire coding region and the flanking 5′ and 3′ regions. We also report AChE1 sequences of larval ticks from R. microplus strains having different sensitivities to OP. To accomplish this, we sequenced a 669-bp region of the AChE1 gene corresponding to a 223 amino acid region of exon 2 to assess alleles in seven strains of R. microplus with varying OP resistance phenotypes. We identified 72 AChE1 sequence variants, 2 of which are strongly associated with OP-resistant phenotypes. Esterase-like sequences from the R. microplus transcriptome RmiTr Version 1.0 were compared to the available sequence databases to identify other transcripts with similarity to AChE1.


July 7, 2019

Genome sequence of the haloarchaeon Haloterrigena jeotgali type strain A29(T) isolated from salt-fermented food.

Haloterrigena jeotgali is a halophilic archaeon within the family Natrialbaceae that was isolated from shrimp jeotgal, a traditional Korean salt-fermented food. A29(T) is the type strain of H. jeotgali, and is a Gram-negative staining, non-motile, rod-shaped archaeon that grows in 10 %-30 % (w/v) NaCl. We present the annotated H. jeotgali A29(T) genome sequence along with a summary of its features. The 4,131,621 bp genome with a GC content of 64.9 % comprises 4,215 protein-coding genes and 127 RNA genes. The sequence can provide useful information on genetic mechanisms that enable haloarchaea to endure a hypersaline environment.


July 7, 2019

Whole genome sequence of Pseudomonas aeruginosa F9676, an antagonistic bacterium isolated from rice seed.

Pseudomonas aeruginosa is a group of bacteria, which can be isolated from diverse ecological niches. P. aeruginosa strain F9676 was first isolated from a rice seed sample in 2003. It showed strong antagonism against several plant pathogens. In this study, whole genome sequencing was carried out. The total genome size of F9676 is 6368,008bp with 5586 coding genes (CDS), 67 tRNAs and 3 rRNAs. The genome sequence of F9676 may shed a light on antagonism P. aeruginosa. Copyright © 2015 Elsevier B.V. All rights reserved.


July 7, 2019

Draft genome sequence of Paenibacillus polymyxa strain Mc5Re-14, an antagonistic root endophyte of Matricaria chamomilla.

Paenibacillus polymyxa strain Mc5Re-14 was isolated from the inner root tissue of Matricaria chamomilla (German chamomile). Mc5Re-14 revealed promising in vitro antagonistic activity against plant and opportunistic human pathogens. The 6.0-Mb draft genome reveals genes putatively involved in pathogen suppression and direct and indirect plant growth promotion. Copyright © 2015 Köberl et al.


July 7, 2019

Complete chloroplast genome sequence of MD-2 pineapple and its comparative analysis among nine other plants from the subclass Commelinidae.

Pineapple (Ananas comosus var. comosus) is known as the king of fruits for its crown and is the third most important tropical fruit after banana and citrus. The plant, which is indigenous to South America, is the most important species in the Bromeliaceae family and is largely traded for fresh fruit consumption. Here, we report the complete chloroplast sequence of the MD-2 pineapple that was sequenced using the PacBio sequencing technology.In this study, the high error rate of PacBio long sequence reads of A. comosus’s total genomic DNA were improved by leveraging on the high accuracy but short Illumina reads for error-correction via the latest error correction module from Novocraft. Error corrected long PacBio reads were assembled by using a single tool to produce a contig representing the pineapple chloroplast genome. The genome of 159,636 bp in length is featured with the conserved quadripartite structure of chloroplast containing a large single copy region (LSC) with a size of 87,482 bp, a small single copy region (SSC) with a size of 18,622 bp and two inverted repeat regions (IRA and IRB) each with the size of 26,766 bp. Overall, the genome contained 117 unique coding regions and 30 were repeated in the IR region with its genes contents, structure and arrangement similar to its sister taxon, Typha latifolia. A total of 35 repeats structure were detected in both the coding and non-coding regions with a majority being tandem repeats. In addition, 205 SSRs were detected in the genome with six protein-coding genes contained more than two SSRs. Comparative chloroplast genomes from the subclass Commelinidae revealed a conservative protein coding gene albeit located in a highly divergence region. Analysis of selection pressure on protein-coding genes using Ka/Ks ratio showed significant positive selection exerted on the rps7 gene of the pineapple chloroplast with P less than 0.05. Phylogenetic analysis confirmed the recent taxonomical relation among the member of commelinids which support the monophyly relationship between Arecales and Dasypogonaceae and between Zingiberales to the Poales, which includes the A. comosus.The complete sequence of the chloroplast of pineapple provides insights to the divergence of genic chloroplast sequences from the members of the subclass Commelinidae. The complete pineapple chloroplast will serve as a reference for in-depth taxonomical studies in the Bromeliaceae family when more species under the family are sequenced in the future. The genetic sequence information will also make feasible other molecular applications of the pineapple chloroplast for plant genetic improvement.


July 7, 2019

The genome of the Saprophytic fungus Verticillium tricorpus reveals a complex effector repertoire resembling that of its pathogenic relatives.

Vascular wilts caused by Verticillium spp. are destructive plant diseases affecting hundreds of hosts. Only a few Verticillium spp. are causal agents of vascular wilt diseases, of which V. dahliae is the most notorious pathogen, and several V. dahliae genomes are available. In contrast, V. tricorpus is mainly known as a saprophyte and causal agent of opportunistic infections. Based on a hybrid approach that combines second and third generation sequencing, a near-gapless V. tricorpus genome assembly was obtained. With comparative genomics, we sought to identify genomic features in V. dahliae that confer the ability to cause vascular wilt disease. Unexpectedly, both species encode similar effector repertoires and share a genomic structure with genes encoding secreted proteins clustered in genomic islands. Intriguingly, V. tricorpus contains significantly fewer repetitive elements and an extended spectrum of secreted carbohydrate- active enzymes when compared with V. dahliae. In conclusion, we highlight the technical advances of a hybrid sequencing and assembly approach and show that the saprophyte V. tricorpus shares many hallmark features with the pathogen V. dahliae.


July 7, 2019

Complete genome sequence of Vibrio anguillarum strain NB10, a virulent isolate from the Gulf of Bothnia.

Vibrio anguillarum causes a fatal hemorrhagic septicemia in marine fish that leads to great economical losses in aquaculture world-wide. Vibrio anguillarum strain NB10 serotype O1 is a Gram-negative, motile, curved rod-shaped bacterium, isolated from a diseased fish on the Swedish coast of the Gulf of Bothnia, and is slightly halophilic. Strain NB10 is a virulent isolate that readily colonizes fish skin and intestinal tissues. Here, the features of this bacterium are described and the annotation and analysis of its complete genome sequence is presented. The genome is 4,373,835 bp in size, consists of two circular chromosomes and one plasmid, and contains 3,783 protein-coding genes and 129 RNA genes.


July 7, 2019

Complete genome sequence of Bacillus thuringiensis HS18-1.

Bacillus thuringiensis is a spore-forming bacterium that is a type of insect pathogen used in the field of microbial insect control. B. thuringiensis HS18-1 has effective toxicity for Lepidoptera and Diptera insects. It contains different types of parasporal crystal genes, including cry4Cb1, cry50Aa1, cry69Ab1, cry30Ga, cry30Ea, cry70Aa, cry71Aa, cry72Aa, cry56Aa and cry54Ba. Here, we report the complete genome sequence of B. thuringiensis HS18-1, which contains one circular gapless chromosome and nine circular plasmids. Copyright © 2015. Published by Elsevier B.V.


July 7, 2019

Complete mitochondrial genome of the medicinal fungus Ophiocordyceps sinensis.

As part of a genome sequencing project for Ophiocordyceps sinensis, strain 1229, a complete mitochondrial (mt) genome was assembled as a single circular dsDNA of 157,510?bp, one of the largest reported for fungi. Conserved genes including the large and small rRNA subunits, 27 tRNA and 15 protein-coding genes, were identified. In addition, 58 non-conserved open reading frames (ncORFs) in the intergenic and intronic regions were also identified. Transcription analyses using RNA-Seq validated the expression of most conserved genes and ncORFs. Fifty-two introns (groups I and II) were found within conserved genes, accounting for 68.5% of the genome. Thirty-two homing endonucleases (HEs) with motif patterns LAGLIDADG (21) and GIY-YIG (11) were identified in group I introns. The ncORFs found in group II introns mostly encoded reverse transcriptases (RTs). As in other hypocrealean fungi, gene contents and order were found to be conserved in the mt genome of O. sinensis, but the genome size was enlarged by longer intergenic regions and numerous introns. Intergenic and intronic regions were composed of abundant repetitive sequences usually associated with mobile elements. It is likely that intronic ncORFs, which encode RTs and HEs, may have contributed to the enlarged mt genome of O. sinensis.


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