Venom-gland transcriptomics and venom proteomics of the giant Florida blue centipede, Scolopendra viridis

Abstract

The limited number of centipede venom characterizations have revealed a rich diversity of toxins, and recent work has suggested centipede toxins may be more rapidly diversifying than previously considered. Additionally, many identified challenges in venomics research, including assembly and annotation methods, toxin quantification, and the ability to provide biological or technical replicates, have yet to be addressed in centipede venom characterizations. We performed high-throughput, quantifiable transcriptomic and proteomic methods on two individual Scolopendra viridis centipedes from North Florida. We identified 39 toxins that were proteomically confirmed, and 481 nontoxins that were expressed in the venom gland of S. viridis. The most abundant toxins expressed in the venom of S. viridis belonged to calcium and potassium ion-channel toxins, venom allergens, metalloproteases, and β-pore forming toxins. We compared our results to the previously characterized S. viridis from Morelos, Mexico, and found only five proteomically confirmed toxins in common to both localities, suggesting either extreme toxin divergence within S. viridis, or that these populations may represent entirely different species. By using multiple assembly and annotation methods, we generated a comprehensive and quantitative reference transcriptome and proteome of a Scolopendromorpha centipede species, while overcoming some of the challenges present in venomics research.

Parallel Evolution of Complex Centipede Venoms Revealed by Comparative Proteotranscriptomic Analyses

“…2017; Drukewitz et al. 2018; Smith and Undheim 2018; Ward and Rokyta 2018). Although methodological or expression-level related factors may contribute to these discrepancies, an important reason why transcriptomic venom profiles on their own can be misleading is that venom toxins evolve from nontoxin ancestral proteins and peptides.…”

“…2013). Ward and Rokyta (2018) sequenced the venom gland transcriptome of an S. viridis individual with Illumina HiSeq technology, which they used to identify 39 protein families in its venom proteome. These represent 16 toxin families when reclassified according to the phylogeny-based toxin classification adopted in our paper.…”

“…2015; Rong et al. 2015; Smith and Undheim 2018; Ward and Rokyta 2018). This taxonomic bias toward scolopendromorphs is equally conspicuous in the recent surge of papers exploring the promise of centipede venoms for the discovery and development of new pharmaceuticals (Yang et al.…”

“…Although the majority of these components remain to be functionally characterized, for brevity we will refer to them as toxins and toxin families throughout the paper. Interestingly, although there is variation in venom composition between, as well as within, scolopendromorph species (Smith and Undheim 2018; Ward and Rokyta 2018), the most striking differences are observed between the venoms of scolopendromorphs and the only nonscolopendromorph studied to date, the scutigeromorph Thereuopoda longicornis (Undheim, Jones, et al. 2014).…”

Optimization of the de novo assembly of the transcriptome of the venom gland of Pamphobeteus verdolaga, prospecting novel bioactive peptides

“…Some of the hits can also be traced to organisms outside the Araneae order. Such examples are the homology of one of the predicted sequences to the Kazal-type serine protease inhibitor from the lobster Sagmariasus verreauxi (66), four ORFs homolog to species of the genera Scolopendra: Scolopendin 1 and 2, both antimicrobial and antifungal peptides (67,68), the toxin SLPTX10-4 of unknown function (69) and lastly Scolopendrasin VII, an anticancer peptide (70). Finally, 14 ORFs also showed homology to the protein Techylectin-1 from the Phoneutria nigriventer, which is also homolog to the toxin Techylectin-5B, an antimicrobial lectin from the horseshoe crab Tachypleus tridentatus (71).…”