scholarly journals Diet Diversity in Carnivorous Terebrid Snails Is Tied to the Presence and Absence of a Venom Gland

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 108
Author(s):  
Juliette Gorson ◽  
Giulia Fassio ◽  
Emily S. Lau ◽  
Mandë Holford
Keyword(s):  
Venom Gland ◽  
Molecular Study ◽  
Strongly Correlated ◽  
Animal Evolution ◽  
Diet Diversity ◽  
Dietary Breadth ◽  
Venom Composition ◽  
Marine Snails ◽  
Predatory Strategy ◽  
Definition Of

Predator-prey interactions are thought to play a driving role in animal evolution, especially for groups that have developed venom as their predatory strategy. However, how the diet of venomous animals influences the composition of venom arsenals remains uncertain. Two prevailing hypotheses to explain the relationship between diet and venom composition focus on prey preference and the types of compounds in venom, and a positive correlation between dietary breadth and the number of compounds in venom. Here, we examined venom complexity, phylogenetic relationship, collection depth, and biogeography of the Terebridae (auger snails) to determine if repeated innovations in terebrid foregut anatomy and venom composition correspond to diet variation. We performed the first molecular study of the diet of terebrid marine snails by metabarcoding the gut content of 71 terebrid specimens from 17 species. Our results suggest that the presence or absence of a venom gland is strongly correlated with dietary breadth. Specifically, terebrid species without a venom gland displayed greater diversity in their diet. Additionally, we propose a revision of the definition of venom complexity in conoidean snails to more accurately capture the breadth of ecological influences. These findings suggest that prey diet is an important factor in terebrid venom evolution and diversification and further investigations of other understudied organisms, like terebrids, are needed to develop robust hypotheses in this area.

scholarly journals Effects of Predator-Prey Interactions on Predator Traits: Differentiation of Diets and Venoms of a Marine Snail

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 299 ◽  
Author(s):  
David A. Weese ◽  
Thomas F. Duda
Keyword(s):  
Resource Utilization ◽  
Species Interactions ◽  
Expression Patterns ◽  
Easter Island ◽  
Island Population ◽  
Predator Prey ◽  
Dietary Breadth ◽  
Venom Composition ◽  
Marine Snails ◽  
Prey Utilization

Species interactions are fundamental ecological forces that can have significant impacts on the evolutionary trajectories of species. Nonetheless, the contribution of predator-prey interactions to genetic and phenotypic divergence remains largely unknown. Predatory marine snails of the family Conidae exhibit specializations for different prey items and intraspecific variation in prey utilization patterns at geographic scales. Because cone snails utilize venom to capture prey and venom peptides are direct gene products, it is feasible to examine the evolution of genes associated with changes in resource utilization. Here, we compared feeding ecologies and venom duct transcriptomes of individuals from three populations of Conus miliaris, a species that exhibits geographic variation in prey utilization and dietary breadth, in order to determine the extent to which dietary differences are correlated with differences in venom composition, and if expanded niche breadth is associated with increased variation in venom composition. While populations showed little to no overlap in resource utilization, taxonomic richness of prey was greatest at Easter Island. Changes in dietary breadth were associated with differences in expression patterns and increased genetic differentiation of toxin-related genes. The Easter Island population also exhibited greater diversity of toxin-related transcripts, but did not show increased variance in expression of these transcripts. These results imply that differences in dietary breadth contribute more to the structural and regulatory differentiation of venoms than differences in diet.

It is high time that taxonomists follow the Code. 3. The Bungarus romulusi case (Serpentes, Elapidae)

Bionomina ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 120-122
Author(s):  
ALAIN DUBOIS ◽  
THIERRY FRÉTEY ◽  
IVAN INEICH
Keyword(s):  
Venom Gland ◽  
Molecular Study ◽  
High Time ◽  
Snake Species ◽  
Mitochondrial Markers

Sunagar et al. (2021: 1) erected the new snake species Bungarus romulusi on the basis of the molecular study of mitochondrial markers, venom proteomics and venom gland transcriptomics. Unfortunately, this new specific nomen is nomenclaturally unavailable, and should therefore not be used as valid as long as it has not been properly published.

STRONGLY CORRELATED FUNCTIONS IN RELIABILITY—PHYSICAL APPROACH

1994 ◽  
Vol 01 (01) ◽  
pp. 63-69 ◽  
Author(s):  
ANDREW H. RAWICZ
Keyword(s):  
Heat Conductivity ◽  
Electrical Resistance ◽  
Physical Parameters ◽  
Strongly Correlated ◽  
Acoustic Attenuation ◽  
Chemical Parameter ◽  
New Approach ◽  
Reliability Measure ◽  
Physical Chemical ◽  
Definition Of

A new approach to reliability called Strongly Correlated Functions is proposed in this paper based on the definition of reliability as a physical magnitude rather than as a probabilistic one. The reliability measure (e.g., life-length) of a component or a product treated as a physical/chemical parameter allows for the construction of analytic correlations between the reliability measure and other physical parameters such as electrical resistance, heat conductivity, or acoustic attenuation that can be nondestructively and quickly determined by a direct measurement. Examples of Strongly Correlated Functions applied to micro wire-joints are presented.

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.

scholarly journals The first discovery on the sporophytes of a rheophytic moss: Bryocrumia vivicolor (Bryophyta, Hypnaceae)

Phytotaxa ◽  
2016 ◽  
Vol 265 (1) ◽  
pp. 73 ◽  
Author(s):  
WEN-ZHANG MA ◽  
JAMES R. SHEVOCK ◽  
SI HE
Keyword(s):  
Cell Walls ◽  
Yunnan Province ◽  
Molecular Study ◽  
Basic Definition ◽  
Widespread Species ◽  
Definition Of ◽  
First Time ◽  
Obtuse Apex ◽  
Made In

Based on recent collections made in Yunnan Province, China, the sporophytes of Bryocrumia vivicolor were discovered for the first time for this species. With typical hypnoid peristome teeth, short operculum, and slightly collenchymatous exothecial cell walls, the capsule of B. vivicolor conforms to the basic definition of Hypnaceae, and this monospecific genus is deemed to belong in Hypnoideae according to current circumscription of the subfamily. Although the identity of Bryocrumia seems to be well-supported morphologically by the additional features such as the bluntly obtuse apex of perichaetial leaves and the deciduous annulus consisting of irregular-shaped cells in 1–2 rows, future molecular study could provide useful insights in understanding the distribution of this rarely collected yet geographically widespread species.

scholarly journals Transcriptomic-Proteomic Correlation in the Predation-Evoked Venom of the Cone Snail, Conus imperialis

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 177 ◽  
Author(s):  
Ai-Hua Jin ◽  
Sébastien Dutertre ◽  
Mriga Dutt ◽  
Vincent Lavergne ◽  
Alun Jones ◽  
...  
Keyword(s):  
Geographical Location ◽  
Venom Gland ◽  
Feeding Habit ◽  
Poor Correlation ◽  
Stabilizing Selection ◽  
Cone Snail ◽  
Venom Composition ◽  
Cone Snails ◽  
And Gender ◽  
Labelling Method

Individual variation in animal venom has been linked to geographical location, feeding habit, season, size, and gender. Uniquely, cone snails possess the remarkable ability to change venom composition in response to predatory or defensive stimuli. To date, correlations between the venom gland transcriptome and proteome within and between individual cone snails have not been reported. In this study, we use 454 pyrosequencing and mass spectrometry to decipher the transcriptomes and proteomes of the venom gland and corresponding predation-evoked venom of two specimens of Conus imperialis. Transcriptomic analyses revealed 17 conotoxin gene superfamilies common to both animals, including 5 novel superfamilies and two novel cysteine frameworks. While highly expressed transcripts were common to both specimens, variation of moderately and weakly expressed precursor sequences was surprisingly diverse, with one specimen expressing two unique gene superfamilies and consistently producing more paralogs within each conotoxin gene superfamily. Using a quantitative labelling method, conotoxin variability was compared quantitatively, with highly expressed peptides showing a strong correlation between transcription and translation, whereas peptides expressed at lower levels showed a poor correlation. These results suggest that major transcripts are subject to stabilizing selection, while minor transcripts are subject to diversifying selection.

scholarly journals Venom Diversity and Evolution in the Most Divergent Cone Snail Genus Profundiconus

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 623 ◽  
Author(s):  
Giulia Fassio ◽  
Maria Vittoria Modica ◽  
Lou Mary ◽  
Paul Zaharias ◽  
Alexander E. Fedosov ◽  
...  
Keyword(s):  
De Novo ◽  
Venom Gland ◽  
Phylogenetic Position ◽  
Cone Snail ◽  
Dietary Breadth ◽  
The Family ◽  
New Gene ◽  
Peptide Toxins ◽  
Transcript Diversity ◽  
Venom Evolution

Profundiconus is the most divergent cone snail genus and its unique phylogenetic position, sister to the rest of the family Conidae, makes it a key taxon for examining venom evolution and diversity. Venom gland and foot transcriptomes of Profundiconus cf. vaubani and Profundiconus neocaledonicus were de novo assembled, annotated, and analyzed for differential expression. One hundred and thirty-seven venom components were identified from P. cf. vaubani and 82 from P. neocaledonicus, with only four shared by both species. The majority of the transcript diversity was composed of putative peptides, including conotoxins, profunditoxins, turripeptides, insulin, and prohormone-4. However, there were also a significant percentage of other putative venom components such as chymotrypsin and L-rhamnose-binding lectin. The large majority of conotoxins appeared to be from new gene superfamilies, three of which are highly different from previously reported venom peptide toxins. Their low conotoxin diversity and the type of insulin found suggested that these species, for which no ecological information are available, have a worm or molluscan diet associated with a narrow dietary breadth. Our results indicate that Profundiconus venom is highly distinct from that of other cone snails, and therefore important for examining venom evolution in the Conidae family.

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 Disorders of sex development: a genetic study of patients in a multidisciplinary clinic

2014 ◽  
Vol 3 (4) ◽  
pp. 180-192 ◽  
Author(s):  
Luigi Laino ◽  
Silvia Majore ◽  
Nicoletta Preziosi ◽  
Barbara Grammatico ◽  
Carmelilia De Bernardo ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Genetic Defect ◽  
Disorders Of Sex Development ◽  
External Genitalia ◽  
Molecular Study ◽  
Testicular Development ◽  
Androgen Synthesis ◽  
Sex Development ◽  
Dna Alterations ◽  
Definition Of

Sex development is a process under genetic control directing both the bi-potential gonads to become either a testis or an ovary, and the consequent differentiation of internal ducts and external genitalia. This complex series of events can be altered by a large number of genetic and non-genetic factors. Disorders of sex development (DSD) are all the medical conditions characterized by an atypical chromosomal, gonadal, or phenotypical sex. Incomplete knowledge of the genetic mechanisms involved in sex development results in a low probability of determining the molecular definition of the genetic defect in many of the patients. In this study, we describe the clinical, cytogenetic, and molecular study of 88 cases with DSD, including 29 patients with 46,XY and disorders in androgen synthesis or action, 18 with 46,XX and disorders in androgen excess, 17 with 46,XY and disorders of gonadal (testicular) development, 11 classified as 46,XX other, eight with 46,XX and disorders of gonadal (ovarian) development, and five with sex chromosome anomalies. In total, we found a genetic variant in 56 out of 88 of them, leading to the clinical classification of every patient, and we outline the different steps required for a coherent genetic testing approach. In conclusion, our results highlight the fact that each category of DSD is related to a large number of different DNA alterations, thus requiring multiple genetic studies to achieve a precise etiological diagnosis for each patient.

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