scholarly journals Community venomics reveals intra-species variations in venom composition of a local population of Vipera kaznakovi in Northeastern Turkey

2018 ◽  
Author(s):  
Daniel Petras ◽  
Benjamin-Florian Hempel ◽  
Bayram Göçmen ◽  
Mert Karis ◽  
Gareth Whiteley ◽  
...  
Keyword(s):  
Snake Venom ◽  
Local Population ◽  
Venom Gland ◽  
Intact Protein ◽  
List Type ◽  
Snake Venoms ◽  
Top Down ◽  
Bottom Up ◽  
Venom Composition ◽  
Snake Bites

AbstractWe report on the variable venom composition of a population of the Caucasus viper (Vipera kaznakovi) in Northeastern Turkey. We applied a combination of venom gland transcriptomics, as well as de-complexing bottom-up and top-down venomics, enabling the comparison of the venom proteomes from multiple individuals. In total, we identified peptides and proteins from 15 toxin families, including snake venom metalloproteinases (svMP; 37.8%), phospholipases A2 (PLA2; 19.0%), snake venom serine proteinases (svSP; 11.5%), C-type lectins (CTL; 6.9%) and cysteine-rich secretory proteins (CRISP; 5.0%), in addition to several low abundant toxin families. Furthermore, we identified intra-species variations of the V. kaznakovi venom composition, and find these were mainly driven by the age of the animals, with lower svSP abundance in juveniles. On a proteoform level, several small molecular weight toxins between 5 and 8 kDa in size, as well as PLA2s, drove the difference between juvenile and adult individuals. This study provides first insights into venom variability of V. kaznakovi and highlights the utility of intact mass profiling for a fast and detailed comparison of snake venoms of individuals from a community.Biological SignificancePopulation level and ontogenetic venom variation (e.g. diet, habitat, sex or age) can cause a loss of antivenom efficacy against snake bites from wide ranging snake populations. The state of the art for the analysis of snake venoms are de-complexing bottom-up proteomics approaches. While useful, these have the significant drawback of being time-consuming and following costly protocols, and consequently are often applied to pooled venom samples. To overcome these shortcomings and to enable rapid and detailed profiling of large numbers of individual venom samples, we integrated an intact protein analysis workflow into a transcriptomics-guided bottom-up approach. The application of this workflow to snake individuals of a local population of V. kaznakovi revealed intra-species variations in venom composition, which are primarily explained by the age of the animals, and highlighted svSP abundance to be one of the molecular drivers for the compositional differences.HighlightsFirst community venomic analysis of a local population of the Caucasian viper (Vipera kaznakovi).The venom gland transcriptome of V. kaznakovi identified 46 toxin genes relating to 15 venom toxin families.Bottom-up venomics revealed the identification of 25 proteins covering 7 toxin families mainly dominated by snake venom metalloproteinases (svMP).Community venomics by top-down mass profiling revealed ontogenetic shifts between juvenile and adult snakes.

scholarly journals Auditory attention alterations in migraine: a behavioral and MEG/EEG study

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Orienting Response ◽  
List Type ◽  
Top Down ◽  
Attention Task ◽  
Bottom Up ◽  
Attentional Processes ◽  
Related Potentials ◽  
The Right ◽  
Task Irrelevant

AbstractObjectivesTo evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.Methods19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and MEG/EEG were recorded. Event-related potentials and fields (ERPs/ERFs) were processed and source reconstruction was applied to ERFs.ResultsAt the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).ConclusionsMigraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.SignificanceThe interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.HighlightsMigraineurs performed as well as healthy participants in an attention task.However, EEG markers of both bottom-up and top-down attention are increased.Migraine is also associated with a facilitated recruitment of the right temporo-parietal junction.

scholarly journals Size Matters: An Evaluation of the Molecular Basis of Ontogenetic Modifications in the Composition of Bothrops jararacussu Snake Venom

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 791
Author(s):  
Luciana A. Freitas-de-Sousa ◽  
Pedro G. Nachtigall ◽  
José A. Portes-Junior ◽  
Matthew L. Holding ◽  
Gunnar S. Nystrom ◽  
...  
Keyword(s):  
Gene Expression ◽  
Snake Venom ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Venom Gland ◽  
Ontogenetic Changes ◽  
Bothrops Jararacussu ◽  
Phospholipases A2 ◽  
Venom Composition ◽  
Putative Toxin

Ontogenetic changes in venom composition have been described in Bothrops snakes, but only a few studies have attempted to identify the targeted paralogues or the molecular mechanisms involved in modifications of gene expression during ontogeny. In this study, we decoded B. jararacussu venom gland transcripts from six specimens of varying sizes and analyzed the variability in the composition of independent venom proteomes from 19 individuals. We identified 125 distinct putative toxin transcripts, and of these, 73 were detected in venom proteomes and only 10 were involved in the ontogenetic changes. Ontogenetic variability was linearly related to snake size and did not correspond to the maturation of the reproductive stage. Changes in the transcriptome were highly predictive of changes in the venom proteome. The basic myotoxic phospholipases A2 (PLA2s) were the most abundant components in larger snakes, while in venoms from smaller snakes, PIII-class SVMPs were the major components. The snake venom metalloproteinases (SVMPs) identified corresponded to novel sequences and conferred higher pro-coagulant and hemorrhagic functions to the venom of small snakes. The mechanisms modulating venom variability are predominantly related to transcriptional events and may consist of an advantage of higher hematotoxicity and more efficient predatory function in the venom from small snakes.

Preliminary Biochemical and Venomic Characterization of the Venom of Phalotris lemniscatus (Serpentes, Colubridae)

2019 ◽  
Vol 19 (22) ◽  
pp. 1981-1989 ◽  
Author(s):  
Jeny Bastida ◽  
Alejandro Crampet ◽  
Melitta Meneghel ◽  
Victor Morais
Keyword(s):  
Amino Acid ◽  
Blood Coagulation ◽  
Snake Venom ◽  
Clinical Relevance ◽  
Protein Families ◽  
Snake Venoms ◽  
Highly Active ◽  
Venom Composition ◽  
Kunitz Type

Background: For many decades, research on snake venom toxinology focused mainly on the venoms of Viperidae and Elapidae species, which were traditionally the only ones considered as venomous. However, much less interest has been given to the venom produced by opisthoglyphous colubrid snakes, since they were typically considered of no clinical relevance. Objective: The aim of this work is to perform a preliminary biochemical and venomic characterization of the venom of the colubrid snake Phalotris lemniscatus, a species that has been responsible for two relevant cases of envenomation in Uruguay. Methods: We extracted venom from collected specimens and performed different biochemical and proteomic assays to understand its toxin composition. Results: We found that the venom of P. lemniscatus is composed of protein families typically present in snake venoms, such as metallo and serine preoteases, L-amino acid oxidases, phospholipases A2s, Ctype lectines-like, Kunitz-type proteins and three-finger toxins. Activity assays demonstrated a highly active gelatinolytic component as well as a potent capability to induce blood coagulation. Conclusion: The results indicate that the venom of P. lemniscatus contains hemotoxic activities and components that resemble those found in Viperidae (Bothrops) snakes and that can induce a clinically relevant accident. Further studies are needed to better understand the venom composition of this colubrid snake and its most active compounds.

scholarly journals Intact protein mass spectrometry reveals intraspecies variations in venom composition of a local population of Vipera kaznakovi in Northeastern Turkey

2019 ◽  
Vol 199 ◽  
pp. 31-50 ◽  
Author(s):  
Daniel Petras ◽  
Benjamin-Florian Hempel ◽  
Bayram Göçmen ◽  
Mert Karis ◽  
Gareth Whiteley ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Local Population ◽  
Intact Protein ◽  
Protein Mass ◽  
Protein Mass Spectrometry ◽  
Venom Composition

scholarly journals Bottom-up and top-down control of dispersal across major organismal groups: a coordinated distributed experiment

2017 ◽  
Author(s):  
Emanuel A. Fronhofer ◽  
Delphine Legrand ◽  
Florian Altermatt ◽  
Armelle Ansart ◽  
Simon Blanchet ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Local Population ◽  
Space Use ◽  
Life History Trait ◽  
Population Fluctuations ◽  
Top Down ◽  
Bottom Up ◽  
Ecological Forecasting ◽  
Cascading Effects ◽  
Wide Range

AbstractOrganisms rarely experience a homogeneous environment. Rather, ecological and evolutionary dynamics unfold in spatially structured and fragmented landscapes, with dispersal as the central process linking these dynamics across spatial scales. Because dispersal is a multi-causal and highly plastic life-history trait, finding general drivers that are of importance across species is challenging but highly relevant for ecological forecasting.We here tested whether two fundamental ecological forces and main determinants of local population dynamics, top-down and bottom-up control, generally explain dispersal in spatially structured communities. In a coordinated distributed experiment spanning a wide range of actively dispersing organisms, from protozoa to vertebrates, we show that bottom-up control, that is resource limitation, consistently increased dispersal. While top-down control, that is predation risk, was an equally important dispersal driver as bottom-up control, its effect depended on prey and predator space use and whether dispersal occurred on land, in water or in the air: species that routinely use more space than their predators showed increased dispersal in response to predation, specifically in aquatic environments. After establishing these general causes of dispersal, we used a metacommunity model to show that bottom-up and top-down control of dispersal has important consequences for local population fluctuations as well as cascading effects on regional metacommunity dynamics. Context-dependent dispersal reduced local population fluctuations and desynchronized dynamics between communities, two effects that increase population and community stability.Our study provides unprecedented insights into the generality of the positive resource dependency of dispersal as well as a robust experimental test of current theory predicting that predator-induced dispersal is modulated by prey and predator space use. Our experimental and theoretical work highlights the critical importance of the multi-causal nature of dispersal as well as its cascading effects on regional community dynamics, which are specifically relevant to ecological forecasting.

scholarly journals Old World Vipers—A Review about Snake Venom Proteomics of Viperinae and Their Variations

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 427
Author(s):  
Maik Damm ◽  
Benjamin-Florian Hempel ◽  
Roderich D. Süssmuth
Keyword(s):  
Mass Spectrometry ◽  
Snake Venom ◽  
Regional Differences ◽  
Database Search ◽  
Snake Venoms ◽  
Old World ◽  
Omics Technologies ◽  
Venom Composition ◽  
Continuous Progress ◽  
Literature Database

Fine-tuned by millions of years of evolution, snake venoms have frightened but also fascinated humanity and nowadays they constitute potential resources for drug development, therapeutics and antivenoms. The continuous progress of mass spectrometry techniques and latest advances in proteomics workflows enabled toxinologists to decipher venoms by modern omics technologies, so-called ‘venomics’. A tremendous upsurge reporting on snake venom proteomes could be observed. Within this review we focus on the highly venomous and widely distributed subfamily of Viperinae (Serpentes: Viperidae). A detailed public literature database search was performed (2003–2020) and we extensively reviewed all compositional venom studies of the so-called Old-World Vipers. In total, 54 studies resulted in 89 venom proteomes. The Viperinae venoms are dominated by four major, four secondary, six minor and several rare toxin families and peptides, respectively. The multitude of different venomics approaches complicates the comparison of venom composition datasets and therefore we differentiated between non-quantitative and three groups of quantitative workflows. The resulting direct comparisons within these groups show remarkable differences on the intra- and interspecies level across genera with a focus on regional differences. In summary, the present compilation is the first comprehensive up-to-date database on Viperinae venom proteomes and differentiating between analytical methods and workflows.

scholarly journals The genetics of venom ontogeny in the eastern diamondback rattlesnake (Crotalus adamanteus)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3249 ◽  
Author(s):  
Darin R. Rokyta ◽  
Mark J. Margres ◽  
Micaiah J. Ward ◽  
Elda E. Sanchez
Keyword(s):  
Snake Venom ◽  
Venom Gland ◽  
Ontogenetic Changes ◽  
Intraspecific Divergence ◽  
Full Characterization ◽  
Venom Composition ◽  
Significant Difference ◽  
Diamondback Rattlesnake ◽  
Putative Toxin

The same selective forces that give rise to rapid inter- and intraspecific divergence in snake venoms can also favor differences in venoms across life-history stages. Ontogenetic changes in venom composition are well known and widespread in snakes but have not been investigated to the level of unambiguously identifying the specific loci involved. The eastern diamondback rattlesnake was previously shown to undergo an ontogenetic shift in venom composition at sexual maturity, and this shift accounted for more venom variation than geography. To characterize the genetics underlying the ontogenetic venom compositional change in C. adamanteus, we sequenced adult/juvenile pairs of venom-gland transcriptomes from five populations previously shown to have different adult venom compositions. We identified a total of 59 putative toxin transcripts for C. adamanteus, and 12 of these were involved in the ontogenetic change. Three toxins were downregulated, and nine were upregulated in adults relative to juveniles. Adults and juveniles expressed similar total levels of snake-venom metalloproteinases but differed substantially in their featured paralogs, and adults expressed higher levels of Bradykinin-potentiating and C-type natriuretic peptides, nerve growth factor, and specific paralogs of phospholipases A2 and snake venom serine proteinases. Juvenile venom was more toxic to mice, indicating that the expression differences resulted in a phenotypically, and therefore potentially ecologically, significant difference in venom function. We also showed that adult and juvenile venom-gland transcriptomes for a species with known ontogenetic venom variation were equally effective at individually providing a full characterization of the venom genes of a species but that any particular individual was likely to lack several toxins in their transcriptome. A full characterization of a species’ venom-gene complement therefore requires sequencing more than one individual, although the ages of the individuals are unimportant.

scholarly journals Using ProteoCombiner to integrate bottom-up and top-down proteomics data to improve proteoform identification

2020 ◽  
Author(s):  
Diogo Borges Lima ◽  
Mathieu Dupré ◽  
Magalie Duchateau ◽  
Quentin Giai Gianetto ◽  
Martial Rey ◽  
...  
Keyword(s):  
High Performance ◽  
Proteome Analysis ◽  
Mass Spectrometric ◽  
Intact Protein ◽  
Proteomics Data ◽  
Top Down ◽  
Proteolytic Fragment ◽  
Bottom Up ◽  
Post Translational Modifications ◽  
User Friendly

Abstract Here we present a high-performance software for proteome analysis that combines different mass spectrometric approaches, such as, top-down for intact protein analyses and bottom-up, for proteolytic fragment characterization. ProteoCombiner capitalizes on the data arising from different experiments and proteomics search engines and presents the results in a user-friendly manner. Our tool also provides a rapid and easy visualization, manual validation and comparison of the identified proteoform sequences, including post-translational modifications (PTM) characterization. Thus, ProteoCombiner is recommended for studies dealing with different proteomics strategies, in order to increase confidence in proteoform identification including PTMs.

Psychology and Culture: Top Down Versus Bottom Up?

PsycCRITIQUES ◽  
2005 ◽  
Vol 50 (19) ◽  
Author(s):  
Michael Cole
Keyword(s):  
Top Down ◽  
Bottom Up
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