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opencc-by-4.0Feb 2015View details →

Figure 2 in Noxious arthropods as potential prey of the venomous Javan slow loris (Nycticebus javanicus) in a West Javan volcanic agricultural system

Figure 2. Mean abundance of the most frequently captured arthropod taxa per trap type. Sample size: Malaise trap n = 21, sweep net n = 17, pitfall trap n = 9. Error bars: ± 1 SE.

opencc-zeroOct 2020View details →

Data for: The scales of coevolution: comparative phylogeography and genetic demography of a locally adapted venomous predator and its prey

Coevolutionary theory predicts that differences in the genetic demography of interacting species can influence patterns of local adaptation by affecting the potential of local populations to respond to selection. We conducted a comparative phylogeographic study of venomous rattlesnakes and their venom-resistant ground squirrel prey across California, and assessed how effective population size (Ne) estimates correspond with a previously documented pattern of rattlesnake local adaptation. Using RAD-seq markers, we detected lineage relationships among both the rattlesnakes (Crotalus oreganus ssp.) and ground squirrels (Otospermophilus sp.) that are incongruent with previous phylogenetic hypotheses. Both rattlesnakes and squirrels share a deep divergence at the Sacramento-San Joaquin River Delta. At this broad phylogeographic scale, we found that the locally adapted rattlesnakes had higher Ne than squirrels. At the population scale, snakes also had larger Ne accompanied by larger values of several metrics of population genetic diversity. However, the specific magnitude of local adaptation of venom activity to ground squirrel venom resistance was not significantly correlated with local differences in Ne or other diversity statistics between predator and prey populations, suggesting other factors in the geographic mosaic of coevolution contribute to the specific local-scale outcomes of this interaction. These results suggest an evolutionary mechanism that may explain some (but clearly not all) of rattlesnake local adaptation in this coevolutionary interaction – larger population sizes raise adaptive potential of rattlesnakes compared to ground squirrels.

Data from: Venom gland size and venom complexity – essential trophic adaptations of venomous predators: a case study using spiders

Specialised predators possess variety of adaptations. In the venomous predators this may include size of the venom gland and venom composition. It is expected that due to different foraging strategies predators with a wide trophic niche (generalists) should possess larger venom glands that contain more diversified components than species with a narrow niche (specialists). We focused on spiders, as the most diversified group of venomous predators, in which a wide variety of trophic strategies has evolved. We conducted a comparative analysis using 40 spider species, in which we measured the size of their venom gland and its complexity using proteome profiling methods. The species were classified into three trophic groups: generalists, facultative specialists, and obligatory specialists. We found that the venom glands of generalists are larger than those of obligatory specialists, which is presumably due to more frequent prey capture by the former. The complexity of venom, of peptides (2-15 kDa) and proteins (15-250 kDa), was more diverse in generalists than in specialists. Multivariate analysis of venom revealed significant differences among the three trophic categories only in the complexity of peptides. Our study thus shows that venom gland size and its content have taken different pathways during the evolution of trophic strategies in spiders. Generalists evolved larger venom glands with more complex composition, whereas obligatory specialists possess smaller glands with less diverse chemical structures, presumably containing prey-specific toxins.

opencc-zeroDec 2011View details →

Data from: On the ancestral recruitment of metalloproteinases into the venom of snakes

Tracing the evolutionary history of proteins can reveal insights into gene alterations responsible for changes in structure and function. Here, the origin of snake venom metalloproteinases was rigorously reassessed using phylogenetics and the reconstruction of ancestral sequences. Basal SVMPs are most closely related to ADAM 7, 28 and decysin 1 proteins. Reconstructing the evolutionary history of these proteins and their hypothetical ancestors elucidates progressive alterations in the amino acid composition and structural characteristics of ADAMs/SVMPs through evolutionary time.

opencc-zeroDec 2010View details →

Data from: Phylogentic analysis of serine proteases from Russell's viper (Daboia russelli siamensis) and Agkistrodon piscivorus leucostoma venom

Serine proteases are widely found in snake venoms. They have variety of functions including contributions to hemostasis. In this study, five serine protease were cloned and characterized from two different cDNA libraries. Factor V activator (RVV-V), alpha fibrinogenase (RVAF) and beta fibrinogenase (RVBF) from Russell's viper (Daboia russelli siamensis), and plasminogen activator (APL-PA) and protein C activator (APL-C) from Agkistrodon piscivorus leucostoma. The snake venom serine proteases were clustered in phylogenetic tree according to their functions. KA/KS values suggested that accelerated evolution has occurred in the mature protein-coding regions in cDNAs of snake venom serine proteases.

Data from: Targeted sequencing of venom genes from cone snail genomes improves understanding of conotoxin molecular evolution

To expand our capacity to discover venom sequences from the genomes of venomous organisms, we applied targeted sequencing techniques to selectively recover venom gene superfamilies and non-toxin loci from the genomes of 32 cone snail species (family, Conidae), a diverse group of marine gastropods that capture their prey using a cocktail of neurotoxic peptides (conotoxins). We were able to successfully recover conotoxin gene superfamilies across all species with high confidence (> 100X coverage) and used these data to provide new insights into conotoxin evolution. First, we found that conotoxin gene superfamilies are composed of 1-6 exons and are typically short in length (mean = ~85bp). Second, we expanded our understanding of the following genetic features of conotoxin evolution: (a) positive selection, where exons coding the mature toxin region were often three times more divergent than their adjacent noncoding regions, (b) expression regulation, with comparisons to transcriptome data showing that cone snails only express a fraction of the genes available in their genome (24%-63%), and (c) extensive gene turnover, where Conidae species varied from 120-859 conotoxin gene copies. Finally, using comparative phylogenetic methods, we found that while diet specificity did not predict patterns of conotoxin evolution, dietary breadth was positively correlated with total conotoxin gene diversity. Overall, the targeted sequencing technique demonstrated here has the potential to radically increase the pace at which venom gene families are sequenced and studied, reshaping our ability to understand the impact of genetic changes on ecologically relevant phenotypes and subsequent diversification.

opencc-zeroDec 2016View details →

Data from: Changes in predator exposure, but not diet induce phenotypic plasticity in scorpion venom

Animals embedded between trophic levels must simultaneously balance pressures to deter predators and acquire resources. Venomous animals may use venom toxins to mediate both pressures, and thus changes in this balance may alter the composition of venoms. Basic theory suggests that greater exposure to a predator should induce a larger proportion of defensive venom components relative to offensive venom components, while increases in arms races with prey will elicit the reverse. Alternatively, reducing the need for venom expenditure for food acquisition, for example because of an increase in scavenging, may reduce the production of offensive venom components. Here, we investigated changes in scorpion venom composition using a mesocosm experiment where we manipulated scorpions' exposure to a surrogate vertebrate predator and live and dead prey. After six weeks, scorpions exposed to surrogate predators exhibited significantly different venom chemistry compared with naive scorpions. This change included a relative increase in some compounds toxic to vertebrate cells and a relative decrease in some compounds effective against their invertebrate prey. Our findings provide, to our knowledge, the first evidence for adaptive plasticity in venom composition. These changes in venom composition may increase the stability of food webs involving venomous animals.

Data from: Symbiotic polydnavirus and venom reveal parasitoid to its hyperparasitoids

Symbiotic relationships may provide organisms with key innovations that aid in the establishment of new niches. For example, during oviposition, some species of parasitoid wasps, whose larvae develop inside the bodies of other insects, inject polydnaviruses into their hosts. These symbiotic viruses disrupt host immune responses, allowing the parasitoid's progeny to survive. Here, we show that symbiotic polydnaviruses also have a downside to the parasitoid's progeny by initiating a multi-trophic chain of interactions that reveals the parasitoid larvae to their enemies. These enemies are hyperparasitoids that use the parasitoid progeny as host for their own offspring. We found that the virus and venom injected by the parasitoid during oviposition, but not the parasitoid progeny itself, affected hyperparasitoid attraction towards plant volatiles induced by feeding of parasitized caterpillars We identified activity of virus-related genes in the caterpillar salivary gland. Moreover, the virus affected the activity of elicitors of salivary origin that induce plant responses to caterpillar feeding. The changes in caterpillar saliva were critical in inducing plant volatiles that are used by hyperparsitoids to locate parasitized caterpillars. Our results show that symbiotic organisms may be key drivers of multi-trophic ecological interactions. We anticipate that this phenomenon is widespread in nature, because of the abundance of symbiotic microorganisms across trophic levels in ecological communities. Their role should be more prominently integrated in community ecology to understand organization of natural and managed ecosystems as well as adaptations of individual organisms that are part of these communities.

Data from: Venom of prey-specialised spiders is more toxic to their preferred prey: a result of prey-specific toxins

1. In specialised predators a variety of adaptations have evolved to such a level of specificity that they allow very effective exploitation of focal prey. Venom is an essential adaptive trait of predatory venomous species, such as spiders, yet our knowledge of spider venom is incomplete. 2. In agreement with the prey preference hypothesis, we expected that the venom of spider specialists should be more toxic to focal than to alternative prey, because it is composed of prey-specific toxins. 3. Here we used spiders with three types of trophic specialisations: specialists that were ant-eating, termite-eating, and spider-eating. We compared the efficacy of prey capture of preferred and alternative prey (measured as paralysis latency) with that of related generalists and profiled the venom of the studied species using proteomic methods. We used 22 spider species: six myrmecophagous, two termitophagous, three araneophagous, and 11 euryphagous generalist species belonging to different families. 4. We found that ten of the eleven specialist species induced significantly shorter paralysis latency in preferred prey than in alternative prey. Generalists exhibited either similar efficiency on both prey types or slightly higher efficiency on preferred prey. 5. Multivariate analysis of proteomic profiles (peptides and proteins) revealed significant differences between trophic specialisations, particularly in peptides. Specialists appear to have venom composed of unique specific compounds as revealed by the multivariate ordination and indicator analysis. These components are likely prey-specific toxins.

opencc-by-4.0Mar 2024View details →

Venom gland organogenesis in the common house spider

This archive includes the R codes and data (i.e., kallisto pseudoalignments) to make the gene expression matrix and calculate the fold change. This was use to identify venom gland-specific genes which were used as markers. The file provided include: <ul> <li>bulk_RNA-seq.zip: this folder contains the kallisto pseudoalignments and the genome annotation</li> <li>bulk_RNA-seq.Rmd: R markdown with the codes for the analysis</li> <li>bulk_RNA-seq.html: the knit from the R markdown</li> </ul> In addition, this archive provides the images of the HCR experiments taken as z-stacks using a a Stellaris 5 White Light Laser (Leica Microsystems) inverted confocal microscope. Once unzipped the folder, the files can be opened using Fiji. The developmental stage and the HCR probe set are specified either in the file ot the images' names. There are two sets of multi-HCR experiments: <ul> <li>set 1 includes: toxin (Alexa-488), sum-1 (Alexa-647), and Dll (Alexa-594);</li> <li>set 2 included sage (Alexa-647) and fkh (Alexa-488).</li> </ul>

opencc-by-4.0Nov 2024View details →

raw data - Old Questions, New Answers: Real-World, Long-Term Efficacy of Hymenoptera Venom Immunotherapy: Prevalence of Venom-Induced Anaphylaxis, Risk Factors, Field Sting Reactions

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opencc-by-4.0Nov 2024View details →

Rattlesnakes Venom Bacterial Cultures

Positive Mode, Non-targeted analysis of bacterial isolates from rattlesnake venom.

opencc-zeroMay 2022View details →

Genetic characterization of potential venom resistance proteins in California ground squirrels (Otospermophilus beecheyi) using transcriptome analyses

Understanding the molecular basis of adaptations in coevolving species requires identifying the genes that underlie reciprocally selected phenotypes, such as those involved in venom in snakes and resistance to venom in their prey. In this regard, California ground squirrels (CGS; Otospermophilus beecheyi) are eaten by northern Pacific rattlesnakes (Crotalus oreganus oreganus), but individual squirrels may still show substantial resistance to venom and survive bites. A recent study using proteomics identified venom interactive proteins (VIPs) in the blood serum of CGS. These VIPs represent possible resistance proteins, but the sequences of genes encoding them are unknown despite the value of such data to molecular studies of coevolution. To address this issue, we analyzed a de novo assembled transcriptome from CGS liver tissue—where many plasma proteins are synthesized—and other tissues from this species. We then examined VIP sequences in terms of three characteristics that identify them as possible resistance proteins: evidence for positive selection, high liver expression, and nonsynonymous variation across CGS populations. Based on these characteristics, we identified five VIPs (i.e., alpha-2-macroglobulin, alpha-1-antitrypsin-like protein GS55-LT, apolipoprotein A-II, hibernation-associated plasma protein HP-20, and hibernation-associated plasma protein HP-27) as the most likely candidates for resistance proteins among VIPs identified to date. Four of these proteins have been previously implicated in conferring resistance to venom in mammals, validating our approach. When combined with the detailed information available for rattlesnake venom proteins, these results set the stage for future work focused on understanding coevolutionary interactions at the molecular level between these species.

opencc-by-4.0May 2022View details →

Divergent specialization of simple venom gene profiles among rear-fanged snake genera (Helicops and Leptodeira, Dipsadinae, Colubridae) datasets

Table S1: GenBank accession numbers for mitochondrial sequences by species.

opencc-zeroNov 2019View details →

Data from: Macroevolutionary analyses suggest that environmental factors, not venom apparatus, play key role in Terebridae marine snail diversification

How species diversification occurs remains an unanswered question in predatory marine invertebrates, such as sea snails of the family Terebridae. However, the anatomical disparity found throughput the Terebridae provides a unique perspective for investigating diversification patterns in venomous predators. In this study, a new dated molecular phylogeny of the Terebridae is used as a framework for investigating diversification of the family through time, and for testing the putative role of intrinsic and extrinsic traits, such as shell size, larval ecology, bathymetric distribution, and anatomical features of the venom apparatus, as drivers of terebrid species diversification. Macroevolutionary analysis revealed that when diversification rates do not vary across Terebridae clades, the whole family has been increasing its global diversification rate since 25 Ma. We recovered evidence for a concurrent increase in diversification of depth ranges, while shell size appeared to have undergone a fast divergence early in terebrid evolutionary history. Our data also confirm that planktotrophy is the ancestral larval ecology in terebrids, and evolutionary modeling highlighted that shell size is linked to larval ecology of the Terebridae, with species with long-living pelagic larvae tending to be larger and have a broader size range than lecithotrophic species. Although we recovered patterns of size and depth trait diversification through time and across clades, the presence or absence of a venom gland (VG) did not appear to have impacted Terebridae diversification. Terebrids have lost their venom apparatus several times and we confirm that the loss of a VG happened in phylogenetically clustered terminal taxa and that reversal is extremely unlikely. Our findings suggest that environmental factors, and not venom, have had more influence on terebrid evolution.

opencc-by-4.0Jul 2024View details →

Codes and datasets for the comparative transcriptome analysis of venom glands in parasitoid wasps

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