De Novo sequencing and transcriptome analysis for Tetramorium bicarinatum: a comprehensive venom gland transcriptome analysis from an ant species

Abstract

BackgroundArthropod venoms are invaluable sources of bioactive substances with biotechnological application. The limited availability of some venoms, such as those from ants, has restricted the knowledge about the composition and the potential that these biomolecules could represent. In order to provide a global insight on the transcripts expressed in the venom gland of the Brazilian ant species Tetramorium bicarinatum and to unveil the potential of its products, high-throughput approach using Illumina technology has been applied to analyze the genes expressed in active venom glands of this ant species.ResultsA total of 212,371,758 pairs of quality-filtered, 100-base-pair Illumina reads were obtained. The de novo assemblies yielded 36,042 contigs for which 27,873 have at least one predicted ORF among which 59.77% produce significant hits in the available databases. The investigation of the reads mapping toxin class revealed a high diversification with the major part consistent with the classical hymenopteran venom protein signature represented by venom allergen (33.3%), followed by a diverse toxin-expression profile including several distinct isoforms of phospholipase A1 and A2, venom serine protease, hyaluronidase, protease inhibitor and secapin. Moreover, our results revealed for the first time the presence of toxin-like peptides that have been previously identified from unrelated venomous animals such as waprin-like (snakes) and agatoxins (spiders and conus).The non-toxin transcripts were mainly represented by contigs involved in protein folding and translation, consistent with the protein-secretory function of the venom gland tissue. Finally, about 40% of the generated contigs have no hits in the databases with 25% of the predicted peptides bearing signal peptide emphasizing the potential of the investigation of these sequences as source of new molecules. Among these contigs, six putative novel peptides that show homologies with previously identified antimicrobial peptides were identified.ConclusionsTo the best of our knowledge, this work reports the first large-scale analysis of genes transcribed by the venomous gland of the ant species T. bicarinatum and helps with the identification of Hymenoptera toxin arsenal. In addition, results from this study demonstrate that de novo transcriptome assembly allows useful venom gene expression analysis in a species lacking a genome sequence database.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-987) contains supplementary material, which is available to authorized users.

Proteomic analysis of the venom of the predatory ant Pachycondyla striata (Hymenoptera: Formicidae)

“…This is the first characterization of the venom proteins of P. striata . Our data show that the venom of P. striata is highly diverse, similar to the venom of other ants that have been characterized (Aili et al., , ; Bouzid et al., ; Touchard et al., ). The combination of the three fractionation and analysis methods allowed the identification of 43 proteins in the venom of P. striata .…”

“…PLs are relatively common in ant venoms (Bouzid et al., ) and are among the most studied enzymes in the venom of Hymenoptera (Lima & Brochetto‐Braga ). In animals, four main types of PLs are known: PLA1, PLA2, PLB, and PLC (Touchard et al., ).…”

“…In ants, enzymes with hyaluronidase activity are not described as a major component of the venom except for the Harvester ant Pogonomyrmex sp. (Bouzid et al., ) and they have low activity in comparison with those from social wasps (El‐Safory, Fazary, & Lee, ).…”

Combined Peptidomic and Proteomic Analysis of Electrically Stimulated and Manually Dissected Venom from the South American Bullet Ant Paraponera clavata

“…There was also a large number of proteins in the unknown category, a recurring issue in most venomics studies. This is due to the lack of genomic and transcriptomic bioinformatics data available for a number of venoms, especially those of ants, as well as the added problem of low abundance 'masking' due to high abundance proteins 25,65,79 .…”

Insights into Antimicrobial Peptides from Spiders and Scorpions

“…Animal venoms are excellent sources of potential antimicrobial substances [1,2]. In particular, there are over 40,000 species of known poisonous arthropods.…”