Project description:Yimeng scorpion is a specific geographical indication breed of Yimeng Mountain area in China. The complete mitochondrial genome sequence of Yimeng scorpion was determined for the first time (Accession number MN597087). It is mitochondrial genome (14,840 bp) contains 13 protein-coding genes, 21tRNA genes, 2 ribosomal RNA genes and one large non-coding region (a possible control region). Moreover, tRNA-ASP-loss was observed from the Yimeng scorpion mitochondrial genome. The mitochondrial genome sequence of the Yimeng scorpion enriches data resource for further research on genetic mechanism and classification.

| S-EPMC7748737 | biostudies-literature

Molecular characterization and expression analysis of CSαβ defensin genes from the scorpion Mesobuthus martensii.

Project description:Defensins are important components of innate host defence system against bacteria, fungi, parasites and viruses. Here, we predicted six potential defensin genes from the genome of the scorpion Mesobuthus martensii and then validated four genes from them via the combination of PCR and genomic sequence analysis. These four scorpion defensin genes share the same gene organization and structure of two exons and one phase-I intron with the GT-AG rule. Conserved motif and phylogenetic analysis showed that they belonged to the members of the invertebrate cysteine-stabilized α-helix/β-sheet motif defensin (CSαβ) defensin family. All these four CSαβ defensin genes have the expression feature of constitutive transcription (CON) by the whole scorpion infection model, promoter sequence analysis and dual luciferase assays. Further evolution and comparison analysis found that the invertebrate CSαβ defensin genes from most of arachnids and mollusks appear to share the expression pattern of CON, but those from insects and lower invertebrates (nematodes, annelids, cnidarians and sponges) seem to have identical inducible transcription (IND) after being challenged by microorganisms. Together, we identified four scorpion CSαβ defensin genes with the expression feature of CON, and characterized the diversified expression patterns of the invertebrate CSαβ defensin genes, which will shed insights into the evolution of the invertebrate CSαβ defensin genes and their expression patterns.

| S-EPMC6435467 | biostudies-literature

A Combinational Strategy upon RNA Sequencing and Peptidomics Unravels a Set of Novel Toxin Peptides in Scorpion Mesobuthus martensii.

Project description:Scorpion venom is deemed to contain many toxic peptides as an important source of natural compounds. Out of the two hundred proteins identiﬁed in Mesobuthus martensii (M. martensii), only a few peptide toxins have been found so far. Herein, a combinational approach based upon RNA sequencing and Liquid chromatography-mass spectrometry/mass spectrometry (LC MS/MS) was employed to explore the venom peptides in M. martensii. A total of 153 proteins were identiﬁed from the scorpion venom, 26 previously known and 127 newly identiﬁed. Of the novel toxins, 97 proteins exhibited sequence similarities to known toxins, and 30 were never reported. Combining peptidomic and transcriptomic analyses, the peptide sequence of BmKKx1 was reannotated and four disulﬁde bridges were conﬁrmed within it. In light of the comparison of conservation and variety of toxin amino acid sequences, highly conserved and variable regions were perceived in 24 toxins that were parts of two sodium channel and two potassium channel toxins families. Taking all of this evidences together, the peptidomic analysis on M. martensii indeed identiﬁed numerous novel scorpion peptides, expanded our knowledge towards the venom diversity, and afforded a set of pharmaceutical candidates.

| S-EPMC5086646 | biostudies-literature

Inhibitory Effect of an Acidic Peptide on the Activity of an Antimicrobial Peptide from the Scorpion Mesobuthus martensii Karsch.

Project description:Highly acidic peptides with no disulfide bridges are widely present in the scorpion venoms; however, none of them has been functionally characterized so far. Here, we cloned the full-length cDNA of a short-chain highly acidic peptide (referred to as HAP-1) from a cDNA library made from the venom glands of the Chinese scorpion Mesobuthus martensii Karsch. HAP-1 contains 19 amino acid residues with a predicted IP value of 4.25. Acidic amino residues account for 33.3% of the total residues in the molecule of HAP-1. HAP-1 shows 76⁻98% identities to some scorpion venom peptides that have not yet been functionally characterized. Secondary structure prediction showed that HAP-1 contains a beta-sheet region (residues 9⁻17), and two coiled coil regions (residues 1⁻8 and 18⁻19) located at the N-terminal and C-terminal regions of the peptide, respectively. Antimicrobial assay showed that HAP-1 does not have any effect on the growth of the bacterium Staphylococcus aureus AB94004. However, it potently inhibits the antimicrobial activity of a 13-mer peptide from M. martensii Karsch against Staphylococcus aureus AB94004. This finding is the first characterization of the function of such highly acidic peptides from scorpions.

| S-EPMC6321396 | biostudies-literature

Pinctada martensii

Project description:Pinctada martensii Raw sequence reads

| PRJNA494927 | ENA