The Complete Mitochondrial Genome of the Scorpion Centruroides vittatus (Arachnida: Scorpiones)

The complete mitochondrial genome (mitogenome) of the Striped scorpion (Centruroides vittatus) was assembled from Illumina-based whole genome sequencing. The circular genome is 14,602 bp in length with 13 protein coding genes, 21 tRNA, two rRNAs, a translocation-inversion of tRNALeu compared to the horse shoe crab mitogenome, and the absence of tRNAAsp. The A + T content of the mitogenome is 68.1%. Our Bayesian and maximum likelihood phylogenetic analyses placed the C. vittatus mitogenome as a sister group of C. limpidus and nestled within the new world Buthids

Genome Analyses of a New Mycoplasma Species from the Scorpion Centruroides vittatus

Arthropod Mycoplasma are little known endosymbionts in insects, primarily known as plant disease vectors. Mycoplasma in other arthropods such as arachnids are unknown. We report the first complete Mycoplasma genome sequenced, identified, and annotated from a scorpion, Centruroides vittatus, and designate it as Mycoplasma vittatus. We find the genome is at least a 683,827 bp single circular chromosome with a GC content of 42.7% and with 987 protein-coding genes. The putative virulence determinants include 11 genes associated with the virulence operon associated with protein synthesis or DNA transcription and ten genes with antibiotic and toxic compound resistance. Comparative analysis revealed that the M. vittatus genome is smaller than other Mycoplasma genomes and exhibits a higher GC content. Phylogenetic analysis shows M. vittatus as part of the Hominis group of Mycoplasma. As arthropod genomes accumulate, further novel Mycoplasma genomes may be identified and characterized

Reduced Toxicity of Centruroides vittatus (Say, 1821) May Result from Lowered Sodium β Toxin Gene Expression and Toxin Protein Production

Body tissue and venom glands from an eastern population of the scorpion Centruroides vittatus (Say, 1821) were homogenized and molecular constituents removed to characterize putative sodium β toxin gene diversity, RT-qPCR, transcriptomic, and proteomic variation. We cloned sodium β toxins from genomic DNA, conducted RT-qPCR experiments with seven sodium β toxin variants, performed venom gland tissue RNA-seq, and isolated venom proteins for mass spectrophotometry. We identified >70 putative novel sodium β toxin genes, 111 toxin gene transcripts, 24 different toxin proteins, and quantified sodium β toxin gene expression variation among individuals and between sexes. Our analyses contribute to the growing evidence that venom toxicity among scorpion taxa and their populations may be associated with toxin gene diversity, specific toxin transcripts variation, and subsequent protein production. Here, slight transcript variation among toxin gene variants may contribute to the major toxin protein variation in individual scorpion venom composition

Reduced Toxicity of Centruroides vittatus (Say, 1821) May Result from Lowered Sodium β Toxin Gene Expression and Toxin Protein Production

Body tissue and venom glands from an eastern population of the scorpion Centruroides vittatus (Say, 1821) were homogenized and molecular constituents removed to characterize putative sodium β toxin gene diversity, RT-qPCR, transcriptomic, and proteomic variation. We cloned sodium β toxins from genomic DNA, conducted RT-qPCR experiments with seven sodium β toxin variants, performed venom gland tissue RNA-seq, and isolated venom proteins for mass spectrophotometry. We identified greater than 70 putative novel sodium β toxin genes, 111 toxin gene transcripts, 24 different toxin proteins, and quantified sodium β toxin gene expression variation among individuals and between sexes. Our analyses contribute to the growing evidence that venom toxicity among scorpion taxa and their populations may be associated with toxin gene diversity, specific toxin transcripts variation, and subsequent protein production. Here, slight transcript variation among toxin gene variants may contribute to the major toxin protein variation in individual scorpion venom composition

Genome Analysis of Staphylococcus agnetis, an Agent of Lameness in Broiler Chickens.

Lameness in broiler chickens is a significant animal welfare and financial issue. Lameness can be enhanced by rearing young broilers on wire flooring. We have identified Staphylococcus agnetis as significantly involved in bacterial chondronecrosis with osteomyelitis (BCO) in proximal tibia and femorae, leading to lameness in broiler chickens in the wire floor system. Administration of S. agnetis in water induces lameness. Previously reported in some cases of cattle mastitis, this is the first report of this poorly described pathogen in chickens. We used long and short read next generation sequencing to assemble single finished contigs for the genome and a large plasmid from the chicken pathogen. Comparison of the S. agnetis genome to those of other pathogenic Staphylococci shows that S.agnetis contains a distinct repertoire of virulence determinants. Additionally, the S. agnetis genome has several regions that differ substantially from the genomes of other pathogenic Staphylococci. Comparison of our finished genome to a recent draft genome for a cattle mastitis isolate suggests that future investigations focus on the evolutionary epidemiology of this emerging pathogen of domestic animals

Phylogenetic trees of toxin virulence factors.

<p>Trees were constructed using the closest homologs to <i>S</i>. <i>agnetis</i> toxin proteins from BLASTp searches of refseq proteins from <i>S</i>. <i>hyicus</i>, S.chromgenes, <i>S</i>. <i>pseudintermedius</i> and <i>S</i>. <i>aureus</i>. Tress are for Superantigen-like protein homologs (Panel A), beta hemolysin (Panel B), and exfoliative toxin A (Panel C). The <i>S</i>. <i>agnetis</i> ortholog are prefixed with the ORF number from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0143336#pone.0143336.s001" target="_blank">S1 Table</a>. Details of the alignment strategy are in Materials and Methods.</p

Representative BCO lesions for proximal femora.

<p>Severity of the lesions are scored by macroscopic examination: Femoral Head Separation, FHS (Panel A), Femoral Head Transitional degeneration, FHT (Panel B), Femoral Head Necrosis, FHN (Panels C and D) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0143336#pone.0143336.ref001" target="_blank">1</a>].</p

Summary data of assembly and annotation of the genome of <i>S</i>. <i>agnetis</i> 908.

<p>Summary data of assembly and annotation of the genome of <i>S</i>. <i>agnetis</i> 908.</p

Bacterial species from lame birds based on bone lesion.

<p>Lesion designations were <b>Normal-</b> no macroscopic abnormalities of the proximal femur or tibia; <b>FHS</b>- proximal femoral head separation; <b>FHT-</b>proximal femoral head transitional degeneration; <b>FHN-</b>proximal femoral head necrosis; <b>THN-</b> mild proximal tibial head necrosis; <b>THNs</b>-"severe" THN in which the growth plate was imminently threatened or damaged; and, <b>THNc</b>- "caseous" THN in which caseous exudates or bacterial sequestrae were macroscopically evident [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0143336#pone.0143336.ref001" target="_blank">1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0143336#pone.0143336.ref029" target="_blank">29</a>]. Species identification and Total number of infections diagnosed was as for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0143336#pone.0143336.t001" target="_blank">Table 1</a>.</p><p>Bacterial species from lame birds based on bone lesion.</p

Phylogenetic tree of fibronectin binding proteins from <i>S</i>. <i>agnetis</i> with homologs from <i>S</i>. <i>hyicus</i>.

<p>The protein sequences predicted for the seven ORFs from <i>S</i>. <i>agnetis</i> (see text) were aligned using Clustal W to the five predicted fibronectin proteins for the <i>S</i>. <i>hyicus</i> ATCC11294 genome (AJC entries are accession numbers) representing the closest orthologs in NCBI for the proteins from <i>S</i>. <i>agnetis</i>. The phylogenetic tree includes bootstrap significance for 2500 iterations.</p