Project description:We generated ATAC-seq data for pre- and post-extraction venom gland samples and H3K4me3, H3K27ac, and CTCF ChIP-seq from post-extraction venom gland samples from the Prairie Rattlesnake to investigate patterns of chromatin accessibility, transcription factor binding, and insulation during venom production, and to identify open promoters and active enhancer regions.
Project description:The venom color variation of C. d. terrificus (Cdt) is attributed to the presence of the toxin LAAO. However, the driving mechanisms of such variability have not been studied and identified so far. During the venom milking routine at Butantan Institute, we have noticed that most of the venoms of captive Cdt specimens show a yellowish color, while most of the venoms of wild specimens are white. Here we describe a comparative analysis of long-term captive (LTC) and recently wild-caught (RWC) Cdt, focusing on the enzyme LAAO. For the identification of LAAO in individual venoms, four different approaches were employed: evaluation of the enzymatic activity, SDS-PAGE, Western blotting and ELISA. In addition, mass spectrometry analysis was performed using pooled samples. Although some variation among these methodologies was observed, it was clear the significative higher percentage of individual venom samples presenting LAAO in LTC venoms. LAAO was identified in 60-80% LTC specimens and in only 10-12% of RWC specimens. Furthermore, this enzyme accounts for 5.6% of total venom proteins of LTC Cdt pooled venom, while it corresponds to only 0.7% of RWC Cdt pooled venom. These findings strongly suggest that the captive maintenance increases the expression of LAAO in Cdt venom.
Project description:Both single cell and bulk RNA sequencing was performed on expanding or differentiating snake venom gland organoids (from Aspidelaps Lubricus Cowlesi and Naja Nivea), or tissue (Aspidelaps Lubricus Cowlesi). Bulk RNA sequencing from the snake venom gland, liver and pancreas was performed to construct a de novo transcriptome using Trinity.
Project description: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 expressed sequence tags were generated using Illumina paired-end sequencing technology. A 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). 300 ant specimens from the species Tetramorium bicarinatum were dissected in order to extract the RNA from their venom gland, The whole ant body was used as a reference,
Project description:While cellular transcripts encode rich information that provide key features to understand the molecular basis of snake venom variation, their presence/ abundance does not necessary imply/correlate in the translation of a functional (protein) product. In this study we carried out an analysis of the venom gland proteome of Bothrops jararaca taking into account two distinct phases of its ontogenetic development (i.e. newborn and adult specimens) and the marked sexual dimorphism recently reported on its venom proteome. Proteomic data analysis showed wider dynamic range for toxins when comparing to non-toxins and a dynamic proteome rearrangement in cellular proteins upon B. jararaca development. Differentially expressed proteins covered a number of biological pathways related to protein synthesis, including proteins related to transcription and translation, which were found to be significantly higher expressed in the newborn venom gland. Our results showed that the variation in the expression levels of cellular proteins gives rise to an even higher variation in the dynamic range of the expressed toxins. Upon ageing, the molecular constraints related to protein synthesis together with ecological traits would likely have an impact on the toxin repertoire, which, in the case of B. jararaca species, would enable the species to deal with different prey types during its lifespan.
Project description:Diachasmimorpha longicaudata parasitoid wasps carry a symbiotic poxvirus, known as DlEPV, within the female wasp venom gland. We sequenced RNA from venom gland tissue to identify DlEPV orthologs for 3 conserved poxvirus core genes. The DlEPV ORFs identified from this transcriptome were used to design primers for downstream RT-qPCR analysis and RNAi knockdown experiments.
Project description:Background The generalist dipteran pupal parasitoid Nasonia vitripennis injects 79 venom peptides into the host before egg laying. This venom induces several important changes in the host, including developmental arrest, immunosuppression, and alterations to normal metabolism. It is hoped that diverse and potent bioactivities of N. vitripennis venom provide an opportunity for the design of novel acting drugs. However, currently very little is known about the individual functions of N. vitripennis venom peptides and less than half can be bioinformatically annotated. The paucity of annotation information complicates the design of studies that seek to better understand the potential mechanisms underlying the envenomation response. Although the RNA interference system of N. vitripennis provides an opportunity to functionally characterise venom encoding genes, with 79 candidates this represents a daunting task. For this reason we were interested in determining the expression levels of venom encoding genes in the venom gland, such that this information could be used to rank candidate venoms. To do this we carried out deep sequencing of the transcriptome of the venom gland and neighbouring ovary tissue and used RNA-seq to measure expression from the 79 venom encoding genes. The generation of a specific venom gland transcriptome dataset also provides further opportunities to investigate novel features of this highly specialised organ. Results High throughput sequencing and RNA-seq revealed that the highest expressed venom encoding gene in the venom gland was a serine protease called Nasvi2EG007167, which has previously been implicated in the apoptotic activity of N. vitripennis venom. As expected the RNA-seq confirmed that the N. vitripennis venom encoding genes are almost exclusively expressed in the venom gland relative to the neighbouring ovary tissue. Novel peptides appear to perform key roles in N. vitripennis venom function as only four of the highest 15 expressed venom encoding genes are bioinformatically annotationed. The high throughput sequencing data also provided evidence for the existence of an additional 471 novel genes in the Nasonia genome that are expressed in the venom gland and ovary. Finally, metagenomic analysis of venom gland transcripts identified viral transcripts that may play an important part in the N. vitripennis venom function. Conclusions The expression level information provided here for the 79 venom encoding genes provides an unbiased dataset that can be used by the N. vitripennis community to identify high value candidates for further functional characterisation. These candidates represent bioactive peptides that have value in drug development pipelines.