scholarly journals Venoms of related mammal-eating species of taipans (Oxyuranus) and brown snakes (Pseudonaja) differ in composition of toxins involved in mammal poisoning

2018 ◽  
Author(s):  
Jure Skejic ◽  
David L. Steer ◽  
Nathan Dunstan ◽  
Wayne C. Hodgson
Keyword(s):  
Small Mammals ◽  
Related Species ◽  
South Australia ◽  
Shotgun Proteomics ◽  
Prey Type ◽  
Phospholipase A ◽  
Generalist Predators ◽  
Type Selection ◽  
Venom Composition ◽  
Venom Proteins

AbstractBackgroundTaipans of the genus Oxyuranus are predominately mammal-eating specialists and a majority of Australian brown snakes of the sister genus Pseudonaja are generalist predators, feeding on mammals, lizards and frogs. In this paper, venom composition of several related mammal-eating species was compared using shotgun proteomics.ResultsVenom of Oxyuranus temporalis consisted predominately of α-neurotoxins (three-finger toxin family) and was deficient in phospholipase A2 neurotoxins. In contrast, PLA2 neurotoxins (taipoxin and paradoxin) were abundant in the venoms of other mammal-eating taipan species – Oxyuranus scutellatus and O. microlepidotus. Variation in neurotoxic PLA2 expression was also recorded in mammal-eating brown snakes, some species having high venom levels of textilotoxin or related homologues, for example Pseudonaja textilis and P. nuchalis, and others, such as P. ingrami, lacking them. Venom prothrombinase proteins (fX and fV) were expressed in most mammalivorous lineages, being particularly abundant in some Pseudonaja species. Notably, Oxyuranus temporalis venom was deficient in venom prothrombinase despite a mammal-based diet. Expression of an α-neurotoxin that is lethal to rodents (pseudonajatoxin b) was profoundly down-regulated in Pseudonaja textilis venom sample from Queensland and highly up-regulated in the sample from South Australia despite a report that the snake feeds on rodents in both regions.ConclusionRelated species of taipans and brown snakes that feed on small mammals express different sets of venom proteins toxic to this vertebrate group. This suggests an involvement of factors other than prey type selection in shaping venom proteome composition.

scholarly journals TOXIFY: a deep learning approach to classify animal venom proteins

2019 ◽  
Author(s):  
T Jeffrey Cole ◽  
Michael S Brewer
Keyword(s):  
Protein Sequence ◽  
Software Package ◽  
Shotgun Proteomics ◽  
Learning Approach ◽  
The Novel ◽  
Venom Protein ◽  
Order Of Magnitude ◽  
Gated Recurrent Units ◽  
Venom Proteins ◽  
Generation Sequencing

In the era of Next-Generation Sequencing and shotgun proteomics, the sequences of animal toxigenic proteins are being generated at rates exceeding the pace of traditional means for empirical toxicity verification. To facilitate the automation of toxin identification from protein sequences, we trained Recurrent Neural Networks with Gated Recurrent Units on publicly available datasets. The resulting models are available via the novel software package TOXIFY, allowing users to infer the probability of a given protein sequence being a venom protein. TOXIFY is more than 20X faster and uses over an order of magnitude less memory than previously published methods. Additionally, TOXIFY is more accurate, precise, and sensitive at classifying venom proteins. Availability: https://www.github.com/tijeco/toxify

The nest of the Hastings River mouse Pseudomys oralis.

2002 ◽  
Vol 24 (2) ◽  
pp. 225 ◽  
Author(s):  
PD Meek
Keyword(s):  
Small Mammals ◽  
Plant Material ◽  
South Australia ◽  
Nest Chamber

THE most detailed information on the burrows and nests of Australian small mammals are reported by Watts and Aslin (1981). The nests of several species of Pseudomys have been described and vary between species. Three nests of the New Holland mouse Pseudomys novaehollandiae were excavated from sand burrows and described as being partially comprised of Eucalypt leaves (Kemper 1981). In South Australia, silky mice P. apodemoides construct nests of shredded bark within a nest chamber of approximately 15 cm (Watts and Aslin 1981). The desert mouse P. desertor reputedly builds dry grass nests in shallow constructions (Read et al.1999) and the long-tailed mouse P. higginsi and eastern chestnut mouse P. gracilicaudatus, delicate mouse P. delicatulus and Gould?s mouse P. gouldii all construct nests of plant material (Watts and Aslin 1981; Green 1993; Fox 1995) mostly grass. The nests of the smokey mouse P. fumeus are constructed of dried grass and Allocasuarina needles that are shaped in a cup form (10-15cm in diameter) (Woods and Ford 2000).

scholarly journals Proteotranscriptomic Insights into the Venom Composition of the Wolf Spider Lycosa tarantula

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 501
Author(s):  
Dominique Koua ◽  
Rosanna Mary ◽  
Anicet Ebou ◽  
Celia Barrachina ◽  
Khadija El Koulali ◽  
...  
Keyword(s):  
Prey Capture ◽  
Wolf Spider ◽  
Secretory Proteins ◽  
Crude Venom ◽  
Wolf Spiders ◽  
Original Source ◽  
Venom Composition ◽  
Venom Glands ◽  
Ambush Predators ◽  
Venom Proteins

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.

Feeding ecology of breeding Long-eared Owls in southwestern Idaho

1984 ◽  
Vol 62 (8) ◽  
pp. 1528-1533 ◽  
Author(s):  
Jeffrey S. Marks
Keyword(s):  
Small Mammals ◽  
Feeding Ecology ◽  
Food Selection ◽  
Prey Type ◽  
Birds Of Prey ◽  
Snake River ◽  
Feeding Niche ◽  
Prey Composition ◽  
Breeding Seasons ◽  
Mammal Faunas

Feeding ecology of Long-eared Owls (Asio otus) was investigated in the Snake River Birds of Prey Area, southwestern Idaho, during the breeding seasons of 1980 and 1981. The owls preyed mainly on five genera of small mammals: Peromyscus, Perognathus, Dipodomys, Microtus, and Reithrodontomys. There was considerable variation in prey composition among sites but not between years. In both years the proportion of Perognathus in the diet increased after the young owls fledged. Compared with other North American studies, Long-eared Owls in the Snake River Birds of Prey Area had a wider feeding niche and preyed more extensively on nonmicrotines. The range of prey sizes in Long-eared Owl diets was similar to that in other areas, with most prey weighing less than 100 g. Interlocality differences in the Long-eared Owl feeding niche probably reflect differences in the composition of small mammal faunas. Long-eared Owls in the Snake River Birds of Prey Area appeared to feed opportunistically on a diversity of available small mammals; prey size, rather than prey type, was the most important factor in food selection.

scholarly journals Rapid and differential evolution of the venom composition of a parasitoid wasp depending on the host strain

2019 ◽  
Author(s):  
Fanny Cavigliasso ◽  
Hugo Mathé-Hubert ◽  
Laurent Kremmer ◽  
Christian Rebuf ◽  
Jean-Luc Gatti ◽  
...  
Keyword(s):  
Differential Evolution ◽  
Rapid Evolution ◽  
Intraspecific Variability ◽  
Protein Composition ◽  
Host Strain ◽  
Parasitoid Wasps ◽  
Evolutionary Potential ◽  
Venom Protein ◽  
Venom Composition ◽  
Venom Proteins

AbstractParasitoid wasps rely primarily on venom to suppress the immune response and regulate the physiology of their host. Intraspecific variability of venom protein composition has been documented in some species, but its evolutionary potential is poorly understood. We performed an experimental evolution initiated with crosses of two lines of Leptopilina boulardi of different venom composition to generate variability and create new combinations of venom factors. The offspring were maintained for 10 generations on two strains of Drosophila melanogaster differing in resistance / susceptibility to the parasitoid lines. The venom composition of individuals was characterized by a semi-automatic analysis of 1D SDS-PAGE protein profiles whose accuracy was checked by Western blot analysis of well-characterized venom proteins. Results evidenced a rapid and differential evolution of the venom composition on both hosts and showed that the proteins beneficial on one host can be costly on the other. Overall, we demonstrated the capacity of rapid evolution of the venom composition in parasitoid wasps, important regulators of arthropod populations, suggesting a potential for adaptation to new hosts. Our approach also proved relevant in identifying, among the diversity of venom proteins, those possibly involved in parasitism success and whose role deserves to be deepened.Key ContributionThe venom protein composition of parasitoid wasps can evolve rapidly and differently depending on the host strain. Studying this evolution can help identify new venom proteins possibly involved in parasitism success on a given host.

scholarly journals Platacanthomyids (Rodentia, Mammalia) from the Late Miocene Yuanmou Hominoid Locality of Yunnan, China

2019 ◽  
Vol 75 (3-4) ◽  
pp. 383-396
Author(s):  
Zhuding Qiu ◽  
Xijun Ni
Keyword(s):  
New Species ◽  
Small Mammals ◽  
South China ◽  
Late Miocene ◽  
Related Species ◽  
Occlusal Surface ◽  
Dental Morphology ◽  
Evolutionary Lineage ◽  
Younger Age ◽  
The Family

Abstract Remains of platacanthomyids from Leilao, a late Miocene hominoid locality in Yuanmou, Yunnan, China are described. Five species in three genera are recognized: Neocometes sp., Platacanthomys dianensis Qiu, 1989, Typhlomys aff. T. primitivus Qiu, 1989, T. hipparionum Qiu, 1989 and T. storchi n. sp. Leilao is the only locality that produces fossils of all three known genera of the family Platacanthomyidae. The new species T. storchi is characterized by its huge dimensions and continuous endoloph(id)s and ectoloph(id)s incorporated with the anteroloph(id)s and posteroloph(id)s to encircle the occlusal surface. That the genus Neocometes from southeastern Asia shows a tendency of forming an ectoloph on the upper molars and an endolophid on the lower molars indicates that the South China species probably represents an evolutionary lineage independent from that of European Neocometes. Both P. dianensis and T. aff. T. primitivus exhibit more derived dental morphology than the related species from Shihuiba of Lufeng, suggesting a younger age of the Leilao Fauna, which is incompatible with the conclusion drawn from the studies of other groups of small mammals.

The dynamics of prey selection by the trap-building predator Gasteracantha hasselti

2020 ◽  
Vol 36 (3) ◽  
pp. 87-93
Author(s):  
Radek Michalko ◽  
Ondřej Košulič ◽  
Venus Saksongmuang ◽  
Prasit Wongprom ◽  
Prapinya Siripaiboon ◽  
...  
Keyword(s):  
Prey Availability ◽  
Prey Selection ◽  
Prey Type ◽  
Generalist Predators ◽  
Dynamic Component ◽  
Tropical Lowland ◽  
North Eastern ◽  
Lowland Forests ◽  
Dynamic Components ◽  
Relative Selectivity

AbstractPrey selection by generalist predators can be highly dynamic depending on the prey community structure. However, the dynamics of prey selection at the stage of prey entrapping are rarely investigated in trap-building predators, probably because their traps have been previously considered to intercept mobile prey proportionally to its availability in environment. Here we investigated the dynamics of prey selection by the orb-weaving spider Gasteracantha hasselti (Araneidae) depending on the composition of the available prey in tropical lowland forests located in north-eastern Thailand. We found that Gasteracantha captured a wide variety of prey but selected, on average, mostly Coleoptera and Diptera. The selectivity of Gasteracantha’s webs for Coleoptera was constant across the changes in overall prey availability and prey composition. The web selectivity for Hemiptera decreased rapidly with increasing relative densities of Hemiptera in the environment. The selectivity for Diptera and Hymenoptera increased and decreased, respectively, with their absolute densities in the environment. The relative selectivity of Gasteracantha’s traps for a particular prey type was driven by the presence and density of the highly selected prey rather than overall prey density. The results show that the selectivity of Gasteracantha’s traps for prey had both fixed and dynamic components and the dynamic component was determined by the relative as well as absolute densities of the particular prey types in the environment.

Small mammals in a semi-arid community, with particular reference to Ningaui yvonneae

2000 ◽  
Vol 22 (2) ◽  
pp. 103 ◽  
Author(s):  
SM Carthew ◽  
T Keynes
Keyword(s):  
Community Structure ◽  
Small Mammals ◽  
Small Mammal ◽  
South Australia ◽  
Sampling Period ◽  
Field Trips ◽  
Mus Domesticus ◽  
Small Mammal Community ◽  
Mammal Community ◽  
Semi Arid

Small mammal community structure was investigated at a semi-arid mallee site in the Middleback Ranges of South Australia during 14 field trips conducted over four years. During this time, 291 small mammals were caught from 6579 trap nights (trap success 4.4%). Ningaui yvonneae was the most abundant and frequently recorded species (199 captures), followed by Cercartetus concinnus (75 captures). Other species caught infrequently were Sminthopsis dolichura (2 captures), Notomys mitchellii (3 captures), Pseudomys bolami (2 captures) and Mus domesticus (10 captures). Ningaui yvonneae was the only species caught during all sampling periods. Males were trapped more frequently than females (117 : 43). Recapture rates were low, with only eight of 160 individuals caught during more than one sampling period. This may reflect the mobility of the species. Distances moved between successive recaptures within a sampling period averaged less than 100 m, while between sampling periods distances averaged more than 450 m. This is the first published study to capture N. yvonneae regularly and in reasonable numbers.

Organization of a taxonomically diverse lizard assemblage in Amazonian Ecuador

1996 ◽  
Vol 74 (7) ◽  
pp. 1313-1335 ◽  
Author(s):  
Laurie J. Vitt ◽  
Peter A. Zani
Keyword(s):  
Related Species ◽  
Prey Size ◽  
Principal Component ◽  
Prey Type ◽  
Lizard Species ◽  
Lowland Forest ◽  
Closely Related Species ◽  
Use Patterns ◽  
Microhabitat Distribution ◽  
Order Of Magnitude

Of 22 lizard species studied in eastern Ecuador, 21 were diurnal. Ten were active foragers and 12 were sit-and-wait foragers. Considerable variation existed in habitat and microhabitat distribution and body temperatures among species. Body size varied over an order of magnitude (20–270 mm snout–vent length). Most morphological (size-free) variation among species (77%) was accounted for by two principal component axes and appears tied to phylogeny. Prey size was correlated with lizard size and species were separated by prey size. Low overlaps in microhabitat, habitat, and prey type also separated species. Pseudocommunity analysis indicated structure in the consumer–resource matrix. In some comparisons, prey overlaps among species were greater within than between higher taxa, and closely related species tended to be found in similar habitat patches and microhabitats, suggesting that resource-use patterns are determined to some extent by phylogeny. Ecology, morphology, and phylogeny appear tied together in a complex manner, with resource partitioning contributing to maintenance of structure. Historical interactions among closely related species may have been important in determining which species within particular clades invaded and persisted within local assemblages in lowland forest.

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