scholarly journals Production and packaging of a biological arsenal: Evolution of centipede venoms under morphological constraint

2015 ◽  
Vol 112 (13) ◽  
pp. 4026-4031 ◽  
Author(s):  
Eivind A. B. Undheim ◽  
Brett R. Hamilton ◽  
Nyoman D. Kurniawan ◽  
Greg Bowlay ◽  
Bronwen W. Cribb ◽  
...  

Venom represents one of the most extreme manifestations of a chemical arms race. Venoms are complex biochemical arsenals, often containing hundreds to thousands of unique protein toxins. Despite their utility for prey capture, venoms are energetically expensive commodities, and consequently it is hypothesized that venom complexity is inversely related to the capacity of a venomous animal to physically subdue prey. Centipedes, one of the oldest yet least-studied venomous lineages, appear to defy this rule. Although scutigeromorph centipedes produce less complex venom than those secreted by scolopendrid centipedes, they appear to rely heavily on venom for prey capture. We show that the venom glands are large and well developed in both scutigerid and scolopendrid species, but that scutigerid forcipules lack the adaptations that allow scolopendrids to inflict physical damage on prey and predators. Moreover, we reveal that scolopendrid venom glands have evolved to accommodate a much larger number of secretory cells and, by using imaging mass spectrometry, we demonstrate that toxin production is heterogeneous across these secretory units. We propose that the differences in venom complexity between centipede orders are largely a result of morphological restrictions of the venom gland, and consequently there is a strong correlation between the morphological and biochemical complexity of this unique venom system. The current data add to the growing body of evidence that toxins are not expressed in a spatially homogenous manner within venom glands, and they suggest that the link between ecology and toxin evolution is more complex than previously thought.

Toxicon ◽  
2017 ◽  
Vol 133 ◽  
pp. 1-9 ◽  
Author(s):  
Luciana Godoy Viana ◽  
Richard Hemmi Valente ◽  
Cíntia Scucuglia Heluany ◽  
Andreia Souza-Imberg ◽  
Milene Schmidt Luna ◽  
...  

1978 ◽  
Vol 78 (2) ◽  
pp. 488-502 ◽  
Author(s):  
U Oron ◽  
A Bdolah

The intracellular transport of venom proteins has been studied in active and resting venom glands of the snake Vipera palaestinae by electron microscope radioautography after an intra-arterial injection of [3H]leucine. In the active gland, most of the label is initially (10 min) found over the RER. By 30 min, the relative grain density of the Golgi complex reaches its maximum, with concomitant increase in the labeling of the condensing vacuoles. Later on, a steep increase in radioactivity of the secretory granules is observed. At 3 h, these granules, which comprise about 2% of the cell volume, contain 22% of the total grains. At the following hour, their labeling declines and at the same time the radioactivity of the secreted venom is increased. It is concluded that, in the active cell, venom proteins are transported via the Golgi apparatus into membrane-bounded granules which are the immediate source of the secreted venom. An alternative pathway, which involves the RER cisternae as a storage compartment, seems unlikely, since incorporated label does not accumulate in this compartment after prolonged postpulse intervals. The route of intracellular transport of proteins in the resting glands is similar to that of the active ones, but the rate of synthesis and transport is much slower. The present results and earlier data, thus, show that the increase in the rate of secretion after initiation of a new venom regeneration cycle is the result of accelerated rates of both synthesis and transport.


1997 ◽  
Vol 75 (7) ◽  
pp. 1014-1019 ◽  
Author(s):  
E. Schoeters ◽  
J. Billen ◽  
J. O. Schmidt

Spider wasps, i.e., the family Pompilidae, in general, and those belonging to the genus Pepsis in particular, are acknowledged to possess venoms that are algogenic to humans and thus have the parsimonious functions of causing paralysis and providing defense against predators. The morphological organization of the venom system and its complex convoluted gland closely resembles that in social members of the Vespidae. These features distinguish the venom glands of the Pompilidae from those of the sibling family Mutillidae as well as those of the family Sphecidae, which lack convoluted glands. Although the venom glands in Pepsis species are very similar in morphology to those of social vespids, the lethality of Pepsis venom to mammals is several times less than that of the social common wasps. These findings suggest that in terms of the evolution of venom activity and the associated glandular structures, there was apparently no need for social wasps to develop extra parts of the venom system for producing toxic, lethal, or powerful algogenic components. All of the glandular parts of the venom gland of social wasps were already present in pompilids (and eumenids) and, presumably, in their ancestors.


1952 ◽  
Vol s3-93 (24) ◽  
pp. 391-394
Author(s):  
D. E. BRAGDON ◽  
J.F. A. MCMANUS

1. Activity of the specific alkaline phosphatase, 5-nucleotidase, is intense in the epithelium and secretion of the rattlesnake venom gland. Non-specific alkaline phosphatase activity is lacking. 2. Thyroid epithelium, the smooth muscle of great vessels, and (inconstantly) smooth muscle of abdominal hollow viscera show greater 5-nucleotidase than nonspecific activity. 3. These findings confirm the specificity of 5-nucleotidase.


2021 ◽  
Author(s):  
Giulia Zancolli ◽  
Maarten Reijnders ◽  
Robert Waterhouse ◽  
Marc Robinson-Rechavi

Animals have repeatedly evolved specialized organs and anatomical structures to produce and deliver a cocktail of potent bioactive molecules to subdue prey or predators: venom. This makes it one of the most widespread convergent functions in the animal kingdom. Whether animals have adopted the same genetic toolkit to evolved venom systems is a fascinating question that still eludes us. Here, we performed the first comparative analysis of venom gland transcriptomes from 20 venomous species spanning the main Metazoan lineages, to test whether different animals have independently adopted similar molecular mechanisms to perform the same function. We found a strong convergence in gene expression profiles, with venom glands being more similar to each other than to any other tissue from the same species, and their differences closely mirroring the species phylogeny. Although venom glands secrete some of the fastest evolving molecules (toxins), their gene expression does not evolve faster than evolutionarily older tissues. We found 15 venom gland specific gene modules enriched in endoplasmic reticulum stress and unfolded protein response pathways, indicating that animals have independently adopted stress response mechanisms to cope with mass production of toxins. This, in turns, activates regulatory networks for epithelial development, cell turnover and maintenance which seem composed of both convergent and lineage-specific factors, possibly reflecting the different developmental origins of venom glands. This study represents the first step towards an understanding of the molecular mechanisms underlying the repeated evolution of one of the most successful adaptive traits in the animal kingdom.


Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 501
Author(s):  
Dominique Koua ◽  
Rosanna Mary ◽  
Anicet Ebou ◽  
Celia Barrachina ◽  
Khadija El Koulali ◽  
...  

Spider venoms represent an original source of novel compounds with therapeutic and agrochemical potential. Whereas most of the research efforts have focused on large mygalomorph spiders, araneomorph spiders are equally promising but require more sensitive and sophisticated approaches given their limited size and reduced venom yield. Belonging to the latter group, the genus Lycosa (“wolf spiders”) contains many species widely distributed throughout the world. These spiders are ambush predators that do not build webs but instead rely strongly on their venom for prey capture. Lycosa tarantula is one of the largest species of wolf spider, but its venom composition is unknown. Using a combination of RNA sequencing of the venom glands and venom proteomics, we provide the first overview of the peptides and proteins produced by this iconic Mediterranean spider. Beside the typical small disulfide rich neurotoxins, several families of proteins were also identified, including cysteine-rich secretory proteins (CRISP) and Hyaluronidases. Proteomic analysis of the electrically stimulated venom validated 30 of these transcriptomic sequences, including nine putative neurotoxins and eight venom proteins. Interestingly, LC-MS venom profiles of manual versus electric stimulation, as well as female versus male, showed some marked differences in mass distribution. Finally, we also present some preliminary data on the biological activity of L. tarantula crude venom.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Tadashi Kimura ◽  
Seigo Ono ◽  
Tai Kubo

Tarantula venom glands produce a large variety of bioactive peptides. Here we present the identification of venom components obtained by sequencing clones isolated from a cDNA library prepared from the venom glands of the Chilean common tarantula, Grammostola rosea. The cDNA sequences of about 1500 clones out of 4000 clones were analyzed after selection using several criteria. Forty-eight novel toxin-like peptides (GTx1 to GTx7, and GTx-TCTP and GTx-CRISP) were predicted from the nucleotide sequences. Among these peptides, twenty-four toxins are ICK motif peptides, eleven peptides are MIT1-like peptides, and seven are ESTX-like peptides. Peptides similar to JZTX-64, aptotoxin, CRISP, or TCTP are also obtained. GTx3 series possess a cysteine framework that is conserved among vertebrate MIT1, Bv8, prokineticins, and invertebrate astakines. GTx-CRISP is the first CRISP-like protein identified from the arthropod venom. Real-time PCR revealed that the transcripts for TCTP-like peptide are expressed in both the pereopodal muscle and the venom gland. Furthermore, a unique peptide GTx7-1, whose signal and prepro sequences are essentially identical to those of HaTx1, was obtained.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xuejiao Liao ◽  
Shuai Guo ◽  
Xianmei Yin ◽  
Baosheng Liao ◽  
Mingqian Li ◽  
...  

Abstract Background Bungarus multicinctus, from which a classical Chinese medicine is produced, is known as the most venomous land snake in the world, but the chromatin organization and transcription factor activity during venom replenishment progress have not been explored yet. This study aimed to determine the roles of chromatin structure in toxin activity via bioinformatics and experimental validation. Methods Chromosome conformation capture (Hi-C) analysis was used to examine interactions among chromosomes and identify different scales of chromatin during envenomation in B. multicinctus. Correlations between epigenetic modifications and chromatin structure were verified through ChIP-seq analysis. RNA-seq was used to validate the influence of variation in chromatin structure and gene expression levels on venom production and regulation. Results Our results suggested that intra-chromosomal interactions are more intense than inter-chromosomal interactions among the control group, 3-day group of venom glands and muscles. Through this, we found that compartmental transition was correlated with chromatin interactions. Interestingly, the up-regulated genes in more compartmental switch regions reflect the function of toxin activity. Topologically associated domain (TAD) boundaries enriched with histone modifications are associated with different distributions of genes and the expression levels. Toxin-coding genes in the same loop are highly expressed, implying that the importance of epigenetic regulation during envenomination. On a smaller scale, the epigenetic markers affect transcriptional regulation by controlling the recruitment/inhibition of transcription initiation complexes. Conclusions Chromatin structure and epigenetic modifications could play a vital status role in the mechanisms of venom regulation in B. multicinctus.


Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 247 ◽  
Author(s):  
Jimena I. Cid-Uribe ◽  
Erika P. Meneses ◽  
Cesar V. F. Batista ◽  
Ernesto Ortiz ◽  
Lourival D. Possani

Venom glands and soluble venom from the Mexican scorpion Centruroides limpidus (Karsch, 1879) were used for transcriptomic and proteomic analyses, respectively. An RNA-seq was performed by high-throughput sequencing with the Illumina platform. Approximately 80 million reads were obtained and assembled into 198,662 putative transcripts, of which 11,058 were annotated by similarity to sequences from available databases. A total of 192 venom-related sequences were identified, including Na+ and K+ channel-acting toxins, enzymes, host defense peptides, and other venom components. The most diverse transcripts were those potentially coding for ion channel-acting toxins, mainly those active on Na+ channels (NaScTx). Sequences corresponding to β- scorpion toxins active of K+ channels (KScTx) and λ-KScTx are here reported for the first time for a scorpion of the genus Centruroides. Mass fingerprint corroborated that NaScTx are the most abundant components in this venom. Liquid chromatography coupled to mass spectometry (LC-MS/MS) allowed the identification of 46 peptides matching sequences encoded in the transcriptome, confirming their expression in the venom. This study corroborates that, in the venom of toxic buthid scorpions, the more abundant and diverse components are ion channel-acting toxins, mainly NaScTx, while they lack the HDP diversity previously demonstrated for the non-buthid scorpions. The highly abundant and diverse antareases explain the pancreatitis observed after envenomation by this species.


2002 ◽  
Vol 15 (1) ◽  
pp. 111-124 ◽  
Author(s):  
Michelle C. Callegan ◽  
Michael Engelbert ◽  
David W. Parke ◽  
Bradley D. Jett ◽  
Michael S. Gilmore

SUMMARY Endophthalmitis is a severe inflammation of the interior of the eye caused by the introduction of contaminating microorganisms following trauma, surgery, or hematogenous spread from a distant infection site. Despite appropriate therapeutic intervention, bacterial endophthalmitis frequently results in visual loss, if not loss of the eye itself. Although the pathogenicity of bacterial endophthalmitis has historically been linked with toxin production during infection, a paucity of information exists as to the exact mechanisms of retinal toxicity and the triggers for induction of the intraocular immune response. Recently, research has begun to examine the bacterial and host molecular and cellular events that contribute to ocular damage during endophthalmitis. This review focuses on the causative agents and therapeutic challenges of bacterial endophthalmitis and provides current data from the analysis of the role of bacterial virulence factors and host inflammatory interactions in the pathogenesis of eye infections. Based on these and related studies, a hypothetical model for the molecular pathogenesis of bacterial endopthalmitis is proposed. Identifying and understanding the basic mechanisms of these bacterium-host interactions will provide the foundation for which novel, information-based therapeutic agents are developed in order to prevent vision loss during endophthalmitis.


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