Ontogenetic and sexual differences in the venom of Bothrops moojeni: insights from a litter and its mother.

Variability in snake venom composition is well-documented and crucial for understanding snake ecology and predicting snakebites. In this study, we characterize the venom composition and biological activities of newborn female and male Bothrops moojeni and their mother. Our results reveal significant differences between the venom of newborn females and males, demonstrating a broad and diverse range of proteins. The venoms of newborn females showed higher serine protease effects, increased hemorrhagic activity, and greater lethality compared to the venom of newborn males. However, no differences were observed in phospholipase A2 and coagulant activity. The differences in protein composition and toxic activities between maternal and neonatal venom, as well as between the venoms of newborn females and males, contribute to understanding the diverse outcomes of snakebites. These results underscore the importance of considering sex and ontogeny in understanding venom composition in snakes.

Bothrops venom-induced hemostasis disorders in the rat: Between Scylla and Charybdis.

Hemostasis impairment represents the most threatening consequence of Viperidae envenoming, notably with Bothrops genus. In the French departments of America, B. atrox envenomation in French Guiana may lead to bleeding while B. lanceolatus envenomation in Martinique to thrombosis. Bleeding related to B. atrox envenomation is attributed to vascular damage mediated by venom metalloproteinases and blood uncoagulable state resulting from thrombocytopenia and consumptive coagulopathy. Thrombosis related to B. lanceolatus envenomation are poorly understood. We aimed to compare the effects of B. atrox and B. lanceolatus venoms in the rat to identify the determinants of the hemorrhagic versus thrombotic complications. Viscoelastometry (ROTEM), platelet count, plasma fibrinogen, thrombin generation assay, fibrinography, endothelial (von Willebrand factor, ADAMTS13 activity, ICAM-1, and soluble E-selectin), and inflammatory biomarkers (IL-1ß, IL-6, TNF-α, MCP-1, and PAI-1) were determined in blood samples obtained at H3, H6, and H24 after the subcutaneous venom versus saline injection. In comparison to the control, initial fibrinogen consumption was observed with the two venoms while thrombocytopenia and reduction in the clot amplitude only with B. atrox venom. Moreover, we showed an increase in thrombin generation at H3 with the two venoms, an increase in fibrin generation accompanied with hyperfibrinogenemia at H24 and an increase in inflammatory biomarkers with B. lanceolatus venom. No endothelial damage was found with the two venoms. To conclude, our data support two-sided hemostasis complications in Bothrops envenoming with an initial risk of hemorrhage related to platelet consumption and hypocoagulability followed by an increased risk of thrombosis promoted by the activated inflammatory response and rapid-onset fibrinogen restoration.

The anti-snake activity of Nectandra angustifolia flavonoids on phospholipase A2: In vitro and in silico evaluation.

ETHNOPHARMACOLOGICAL RELEVANCE: Lauraceae family includes Nectandra angustifolia a species widely used in the folk medicine of South America against various maladies. It is commonly used to treat different types of processes like inflammation, pain, and snakebites. Snakes of the Bothrops genus are responsible for about 97% of the ophidic accidents in northeastern Argentina. AIM OF THE STUDY: To evaluate the anti-snake activity of the phytochemicals present in N. angustifolia extracts, identify the compounds, and evaluate their inhibitory effect on phospholipase A2 (PLA2) with in vitro and in silico assays. METHODS: Seasonal variations in the alexiteric potential of aqueous, ethanolic and hexanic extracts were evaluated by inhibition of coagulant, haemolytic, and cytotoxic effects of B. diporus venom. The chemical identity of an enriched fraction obtained by bio-guided fractioning was established by UPLC-MS/MS analysis. Molecular docking studies were carried out to investigate the binding mechanisms of the identified compounds to PLA2 enzyme from snake venom. RESULTS: All the extracts inhibited venom coagulant activity. However, spring ethanolic extract achieved 100% inhibition of haemolytic activity. Bio-guide fractioning led to an enriched fraction (F4) with the highest haemolytic inhibition. Five flavonoids were identified in this fraction; molecular docking and Molecular Dynamics (MD) simulations indicated the binding mechanisms of the identified compounds. The carbohydrates present in some of the compounds had a critical effect on the interaction with PLA2. CONCLUSION: This study shows, for the first time, which compounds are responsible for the anti-snake activity in Nectandra angustifolia based on in vitro and in silico assays. The results obtained in this work support the traditional use of this species as anti-snake in folk medicine.

15N, 13C, and 1H resonance assignments of Jarastatin: a disintegrin of Bothrops jararaca.

Disintegrins are a group of cysteine-rich proteins found in a wide variety of snake venoms. These proteins selectively bind to integrins, which play a fundamental role in the regulation of many physiological and pathological processes. Here, we report the NMR chemical shift assignments for 1H, 15N, and 13C nuclei in the backbone and side chains of recombinant disintegrin Jarastatin (rJast), which was further validated by secondary structure prediction using the TALOS-N server. Taken together, these data are essential to perform NMR-based experiments, including structure determination, backbone dynamics, mapping ligand sites and enabling a deeper understanding of the effect of hydrophobic surface clusters, which are important elements to stabilize some 3D proteins structure/folding.

The role of vicariance and dispersal on the temporal range dynamics of forest vipers in the Neotropical region.

The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is suggested to have acted as a dispersal barrier for terrestrial organisms by fragmenting a single large forest that existed in South America into the present Atlantic and Amazon forests. Here we tested the hypothesis that the expansion of the South American diagonal of open/dry landscapes acted as a vicariant process for forest lanceheads of the genus Bothrops, by analyzing the temporal range dynamics of those snakes. We estimated ancestral geographic ranges of the focal lancehead clade and its sister clade using a Bayesian dated phylogeny and the BioGeoBEARS package. We compared nine Maximum Likelihood models to infer ancestral range probabilities and their related biogeographic processes. The best fitting models (DECTS and DIVALIKETS) recovered the ancestor of our focal clade in the Amazon biogeographic region of northwestern South America. Vicariant processes in two different subclades resulted in disjunct geographic distributions in the Amazon and the Atlantic Forest. Dispersal processes must have occurred mostly within the Amazon and the Atlantic Forest and not between them. Our results suggest the fragmentation of a single ancient large forest into the Atlantic and Amazon forests acting as a driver of vicariant processes for the snake lineage studied, highlighting the importance of the diagonal of open/dry landscapes in shaping distribution patterns of terrestrial biota in South America.

Epidemiology of snake envenomation from Mato Grosso do Sul, Brazil.

Snake envenomation is considered a public health problem in tropical countries, where they occur in a high incidence. The present study reports the snake envenomation that occurred in Mato Grosso do Sul state (Brazil) between 2007 and 2017. Epidemiological data were obtained from the online platform of the Notification Disease Information System and were analyzed according to biome. A total of 5568 cases of snake envenomations were recorded during the study period, where the highest frequency was registered between October and April. The majority of envenomations occurred in working-age males (20 to 39 years), caused mainly by Bothrops snakes, and the duration of care after the envenomation in most cases took three hours. The municipalities that showed the highest snake envenomations case per 100,000 inhabitants presents low population density, and have their economy based on agricultural activity, which is a risk factor to snake envenomations. To the Mato Grosso do Sul state, the total number of snake envenomations had a positive relationship with the size of the municipality. Since this, larger areas usually have a mosaic of environments, which may harbor higher richness and abundance of snakes, and can cause more snake encounters with the population, resulting in more snake envenomations.

Short-term cold storage of seminal samples of the golden lancehead pitviper (Bothrops insularis).

Assisted reproductive technologies such as cooling, freezing, and artificial insemination are essential in conserving genetic diversity of critically endangered reptiles like the golden lancehead pitviper (Bothrops insularis). Therefore, we examined viability of semen samples from captive golden lanceheads diluted in coconut-water based extender over a 48-h period of cooling (5°C). Semen evaluations were performed immediately after the dilution and at 6, 24, and 48 h, using computer-assisted sperm analysis and stains to assess plasma membrane and acrosomal status. Our findings showed that the extender and protocol employed here were effective in preserving golden lancehead pitviper spermatozoa for a short periods of time (48 h), allowing semen samples to be transported to distant locations for immediate use without the setbacks of cryopreservation.

Bothrops bilineatus: An Arboreal Pitviper in the Amazon and Atlantic Forest.

The two-striped forest-pitviper (Bothrops bilineatus) is an arboreal snake that is currently represented by two subspecies (B. b. bilineatus and B. b. smaragdinus) that comprise a species complex, and its distribution is in the Amazon and the Atlantic Forest. The rarity of encounters with this snake is reflected in the low occurrence of cases of snakebites throughout its geographic distribution and the resulting low number of published clinical reports. However, in some areas, B. bilineatus proves to be more frequent and causes envenomations in a greater proportion. Herein, we review the main aspects of the species complex B. bilineatus, including its biology, ecology, taxonomy, morphology, genetic and molecular studies, geographic distribution, conservation status, venom, pathophysiology and clinical aspects, and epidemiology. In addition, the different antivenoms available for the treatment of envenomations caused by B. bilineatus are presented along with suggestions for future studies that are needed for a better understanding of the snakebites caused by this snake.

Short-term captivity does not affect immediate voluntary thermal maximum of a neotropical pitviper: Implications for behavioral thermoregulation.

Ectotherms depend on temperature to maintain their physiological functions and through behavioral changes, they can avoid overheating in their habitats. The voluntary thermal maximum (VTMax ) represents the maximum temperature tolerated by individuals before actively moving to a colder place. However, if and how VTMax might change after capture and in captivity remains understudied. We investigate if measurements taken in captivity are a good proxy for thermal tolerance of wild individuals. As thermal history has been shown to affect behavioral response and physiological parameters, herein we hypothesized that VTMax of the neotropical viper Bothrops pauloensis varies throughout the captivity period. We measured the VTMax of individuals immediately after capture and in three trials during a short-term period in captivity. Measurements were done by recording their body temperature at which they exited a heating box experimental setup. In contrast to our hypothesis, the VTMax was not significantly affected by time in captivity but there was interindividual variation. There were also no significant differences between field and captivity measurements, in spite of the small effect size. Our results indicate that the VTMax of this snake population is not affected by a short-term captivity period. Furthermore, an invariant VTMax might indicate low phenotypic plasticity, as individuals do not appear to adjust their tolerance to short-term exposure to higher temperatures and potential vulnerability to threats such as global warming. We expect that our results can contribute to understanding the effect of captivity on thermal tolerance in neotropical squamates, allowing for insights into their thermal physiology and ecology.

P-I metalloproteinases and L-amino acid oxidases from Bothrops species inhibit angiogenesis

Snake venoms are composed of pharmacologically active proteins that are evolutionarily diverse, stable and specific to targets. Hence, venoms have been explored as a source of bioactive molecules in treating numerous diseases. Recent evidences suggest that snake venom proteins may affect the formation of new blood vessels. Excessive angiogenesis has been implicated in several pathologies including tumours, diabetic retinopathy, arthritis, inter alia. In the present study, we have examined the effects of P-I metalloproteinases isolated from Bothrops moojeni (BmMP-1) and Bothrops atrox (BaMP-1) and L-amino acid oxidases (LAAO) isolated from B. moojeni (BmLAAO) and B. atrox (BaLAAO) on biochemical and functional aspects of angiogenesis. Methods: P-I metalloproteinases and LAAO were purified from venom by molecular size exclusion and ion-exchange chromatography and subsequently confirmed using mass spectrometry. The P-I metalloproteinases were characterized by azocaseinolytic, fibrinogenolytic and gelatinase activity and LAAO activity was assessed by enzyme activity on L-amino acids. Influence of these proteins on apoptosis and cell cycle in endothelial cells was analysed by flow cytometry. The angiogenic activity was determined by in vitro 3D spheroid assay, Matrigel tube forming assay, and in vivo agarose plug transformation in mice. Results: P-I metalloproteinases exhibited azocaseinolytic activity, cleaved α and partially β chain of fibrinogen, and displayed catalytic activity on gelatin. LAAO showed differential activity on L-amino acids. Flow cytometry analysis indicated that both P-I metalloproteinases and LAAO arrested the cells in G0/G1 phase and further induced both necrosis and apoptosis in endothelial cells. In vitro, P-I metalloproteinases and LAAO exhibited significant anti-angiogenic properties in 3D spheroid and Matrigel models by reducing sprout outgrowth and tube formation. Using agarose plug transplants in mice harbouring P-I metalloproteinases and LAAO we demonstrated a marked disruption of vasculature at the periphery. Conclusion: Our research suggests that P-I metalloproteinases and LAAO exhibit anti-angiogenic properties in vitro and in vivo.(AU)

Reproduction in the pitviper Bothrops jararacussu: large females increase their reproductive output while small males increase their potential to mate.

Reproductive traits vary widely within and among snake species, and are influenced by a range of factors. However, additional studies are needed on several species, especially on tropical snake faunas, to fully understand the patterns of reproductive variation in snakes. Here, we characterized the reproductive biology of B. jararacussu from southeastern and southern Brazil. We combined macroscopic and microscopic examinations of the reproductive system of museum specimens with observations of free-ranging snakes to characterize size at sexual maturity, sexual size dimorphism (SSD), reproductive output, and male and female reproductive cycles. We compared our data with published literature and discuss the factors that may play a role in shaping the reproductive patterns in the species and the genus. Bothrops jararacussu shares several characteristics with its congeners such as autumn mating season, obligatory sperm storage in the female reproductive tract, seasonal timing of parturition (summer-autumn), female-biased SSD, maturity at larger body sizes in females, and a positive relationship between body size and litter size. These characteristics seem phylogenetically conserved in Bothrops. On the other hand, B. jararacussu exhibits some unique characteristics such as a high degree of SSD (one of the highest values recorded in snakes), a large female body size, and a large litter and offspring size, which are among the largest recorded in the genus. Moreover, larger females reproduce more frequently than smaller conspecifics. These characteristics may be collectively interpreted as the result of a strong selection for increased fecundity. Other peculiarities of the species include an asynchrony between spermiogenesis (summer-autumn) and the peak of SSK hypertrophy (autumn to spring) and a prolonged production of SSK granules. Because SSK hypertrophy and mating are androgen-dependent in snakes, the prolonged SSK hypertrophy suggests that male B. jararacussu may prolong their potential to mate (compared with its congeners), which may increase their reproductive success. Our results and previous literature collectively suggest that, in Bothrops, the evolution of SSD is driven by fecundity selection, variation in reproductive output is influenced by variation in female body size, and the timing of spermiogenesis is influenced by other factors in addition to temperature. We also suggest that male Bothrops have undergone multiple evolutionary shifts in the timing of spermiogenesis.

A case of envenomation by the false fer-de-lance snake Leptodeira annulata (Linnaeus, 1758) in the department of La Guajira, Colombia. / Un caso de envenenamiento por mordedura de una serpiente falsa cabeza de lanza, Leptodeira annulata (Linnaeus, 1758), en el departamento de La Guajira, Colombia

Envenomations by colubrid snakes in Colombia are poorly known, consequently, the clinical relevance of these species in snakebite accidents has been historically underestimated. Herein, we report the first case of envenomation by opisthoglyphous snakes in Colombia occurred under fieldwork conditions at the municipality of Distracción, in the department of La Guajira. A female biologist was bitten on the index finger knuckle of her right hand when she tried to handle a false fer-de-lance snake (Leptodeira annulata). Ten minutes after the snakebite, the patient started to have symptoms of mild local envenomation such as edema, itching, and pain in the wound. After 40 minutes, the edema reached its maximum extension covering the dorsal surface of the right hand and causing complete loss of mobility. The clinical treatment focused on pain and swelling control. No laboratory tests were performed. The patient showed good progress with the total regression of the edema 120 hours after the snake-bite accident and complete recovery of the movement of the limb in one week. Venomous bites of "non-venomous snakes" (opisthoglyphous colubrid snakes) must be considered as a significant public health problem because patients lose their work capability during hours or even days and they are forced to seek medical assistance to treat the envenomation manifestations.

Los envenenamientos por colúbridos en Colombia son poco conocidos, por lo que la relevancia clínica de estas especies de serpientes en los accidentes ofídicos ha sido históricamente subestimada. Se presenta el primer caso de envenenamiento por una serpiente opistoglifa en Colombia, ocurrido bajo condiciones de trabajo de campo en el municipio de Distracción, departamento de La Guajira. Una bióloga fue mordida en el nudillo del dedo índice de la mano derecha cuando trató de manipular una falsa cabeza de lanza o falsa mapanare (Leptodeira annulata). Diez minutos después de la mordedura de la serpiente, la paciente presentó síntomas de envenenamiento local leve, como edema, picazón y dolor en la herida. Después de 40 minutos, el edema alcanzó su extensión máxima, cubriendo la superficie dorsal de la mano derecha y causando la pérdida completa de la movilidad. El tratamiento clínico se centró en el control del dolor y la inflamación. No se hicieron pruebas de laboratorio. La paciente tuvo una buena evolución, con la regresión total del edema 120 horas después del accidente ofídico y la normalización de los movimientos de la extremidad a la semana. Las mordeduras venenosas de serpientes "no venenosas" (serpientes colúbridas opistoglifas) deben considerarse un problema de salud pública importante, ya que los pacientes pierden la capacidad de trabajo durante horas o días y se ven obligados a buscar asistencia médica para contrarrestar las manifestaciones locales de envenenamiento.

Infundibular sperm storage and uterine muscular twisting in the Amazonian lancehead, Bothrops atrox.

Although knowledge about the reproduction of snakes of the genus Bothrops has increased recently, many questions remain regarding sperm storage by these neotropical pitvipers. The relationship between two known sperm storage sites-the nonglandular uterus and the infundibulum-has yet to be detailed for Bothrops. In addition, the formation of uterine muscular twisting (UMT) and its function in sperm storage in the nonglandular uterus have been questioned. This article presents data on both sperm storage sites (posterior infundibulum and nonglandular uterus) in the Amazonian lancehead, Bothrops atrox, aiming to address the role of UMT in bothropoid reproduction considering female reproductive stages, timing of sperm storage, and morphology and histochemistry of sperm receptacles. The oviduct of B. atrox is composed of the infundibulum (anterior and posterior), the glandular uterus, the nonglandular uterus and the pouch. Sperm storage occurs in the posterior infundibulum and nonglandular uterus in vitellogenic females. In the posterior infundibulum sperm is stored in receptacles, while in the nonglandular uterus it is stored in crypts in the UMT of vitellogenic females. Both sperm storage sites possess granules testing positive for neutral mucopolysaccharides in the presence of spermatozoa, possibly favoring the conditions for spermatozoa surveillance during sperm storage in the reproductive tract.

In-depth transcriptome reveals the potential biotechnological application of Bothrops jararaca venom gland

Lack of complete genomic data of Bothrops jararaca impedes molecular biology research focusing on biotechnological applications of venom gland components. Identification of full-length coding regions of genes is crucial for the correct molecular cloning design. Methods: RNA was extracted from the venom gland of one adult female specimen of Bothrops jararaca. Deep sequencing of the mRNA library was performed using Illumina NextSeq 500 platform. De novo assembly of B. jararaca transcriptome was done using Trinity. Annotation was performed using Blast2GO. All predicted proteins after clustering step were blasted against non-redundant protein database of NCBI using BLASTP. Metabolic pathways present in the transcriptome were annotated using the KAAS-KEGG Automatic Annotation Server. Toxins were identified in the B. jararaca predicted proteome using BLASTP against all protein sequences obtained from Animal Toxin Annotation Project from Uniprot KB/Swiss-Pro database. Figures and data visualization were performed using ggplot2 package in R language environment. Results: We described the in-depth transcriptome analysis of B. jararaca venom gland, in which 76,765 de novo assembled isoforms, 96,044 transcribed genes and 41,196 unique proteins were identified. The most abundant transcript was the zinc metalloproteinase-disintegrin-like jararhagin. Moreover, we identified 78 distinct functional classes of proteins, including toxins, inhibitors and tumor suppressors. Other venom proteins identified were the hemolytic lethal factors stonustoxin and verrucotoxin. Conclusion: It is believed that the application of deep sequencing to the analysis of snake venom transcriptomes may represent invaluable insight on their biotechnological potential focusing on candidate molecules.(AU)

Functional variability of Bothrops atrox venoms from three distinct areas across the Brazilian Amazon and consequences for human envenomings.

Variability in the composition of snake venoms occurs in different taxa and is usually correlated to snake fitness. Here, we compared B. atrox venoms from three different geographic regions across the Brazilian Amazon and found remarkable functional differences particularly between venoms from two populations separated by the Amazon River, in specimens born, raised and maintained under the same conditions at Instituto Butantan serpentary. Venom from Presidente Figueiredo snakes induced stronger dermonecrosis, but was less procoagulant and lethal to mice; these activities were correlated to the presence of a PI-class SVMP and absence of a SVSP in the venom, respectively. Venom from São Bento snakes was more hemorrhagic, killed mice more efficiently, but induced lower signs of dermonecrosis, which was correlated to the higher proportion of SVMPs and the absence of a PI-class SVMP isoform. Belterra snakes, a reference of wild snakes, presented venoms with intermediate phenotypes. Commercial Bothrops antivenom was effective in neutralizing all biological activities evaluated in this study, including dermonecrosis and pro-coagulant, which are relevant for human snakebite accidents by B. atrox. Functional differences correlated to snake fitness may also imply in different symptomatology for B. atrox snakebite patients and deserve special attention from clinical toxicologists.

Photoreceptors morphology and genetics of the visual pigments of Bothrops jararaca and Crotalus durissus terrificus (Serpentes, Viperidae).

Snakes inhabit a great variety of habitats, whose spectral quality of light may vary a lot and influence specific adaptations of their visual system. In this study, we investigated the genetics of the visual opsins and the morphology of retinal photoreceptors, of two nocturnal snakes from the Viperidae family, Bothrops jararaca and Crotalus durissus terrificus, which inhabit preferentially the Atlantic Rain Forest and the Brazilian Savannah, respectively. Total RNA was extracted from homogenized retinas and converted to cDNA. The opsin genes expressed in snake retinas, LWS, RH1, and SWS1, were amplified by polymerase chain reactions (PCRs) and sequenced. The absorption peak (λmax) of the opsins were estimated based on amino acids located at specific spectral tuning sites. Photoreceptor cell populations were analyzed using immunohistochemistry with anti-opsin antibodies. Results showed the same morphological cell populations and same opsins absorption peaks, in both viperid species: double and single cones with LWS photopigment and λmax at ∼555 nm; single cones with SWS1 photopigment and λmax at ∼360 nm; and rods with the rhodopsin RH1 photopigment and λmax at ∼500 nm. The results indicate adaptations to nocturnal habit in both species despite the differences in habitat, and the possibility of a dichromatic color vision at photopic conditions.

Prospective study of a Bothrops jararacussu venom batch (Bj2015) - phospholipase A2 activity, immunogenicity, neurotoxicity, and myotoxicity parameters.

Bothrops jararacussu venom's (Bj2015) batch was biomonitored quarterly for one year to assess phospholipase A2 (PLA2) activity, immunogenicity, neurotoxicity, and myotoxicity. In silico models were applied to evaluate losses using decay model and recoveries by predictive trend analysis. Mice were immunized with Bj2015. Antibodies were detected by double-immunodiffusion and total protein and albumin were measured. Neuromuscular blockade-induced by 40 µg mL-1 venom solution was carried out using mouse nerve phrenic-diaphragm preparation. Resulting muscles were submitted to light microscopy to evaluate the myotoxicity. PLA2 activity of 0.1 mg mL-1 Bj2015 was measured using 4-nitro-3-(octanoyloxy)benzoic acid as substrate. Over time, greater losses occurred in neurotoxicity than PLA2, but not in myotoxicity and immunogenicity. Concluding, the neurotoxicity decrease can be related to enzymatic losses, including PLA2. Depending on the purpose of use, the collected venom responds on a long time, avoiding unnecessary new collections, improving life quality of animals in captivity and increasing their longevity.

The Role of Feeding Specialization on Post-Prandial Metabolic Rate in Snakes of the Genus Bothrops.

Feeding specialization is a recurrent issue in the evolution of snakes and is sometimes associated to morphological and/or behavioral adaptations that improve snake performance to exploit a particular food type. Despite its importance for animal fitness, the role of physiological traits has been much less studied than morphological and behavioral traits in the evolution of feeding specialization in snakes. In this context, the energetic cost of post-prandial period is an important physiological factor due to the remarkable effect on the snake energy budget. We collected data on post-prandial metabolic rate (SDA) in five species of pit vipers from the genus Bothrops with different degrees of mammal feeding specialization to test the hypothesis that feeding specialist species have lower energy costs during the digestion of their regular food item when compared to species with a more generalist diet. Our results support this hypothesis and suggest that ontogenetic changes in diet can be accompanied by changes in energy cost of the digestion process.

Effect of exposition to chlorpyrifos upon plasmatic cholinesterases, hematology and blood biochemistry values in Bothrops asper (Serpentes: Viperidae).

The terciopelo (Bothrops asper), is one of the most important venomous snakes in Costa Rica and common on agriculture where insecticides are frequently used for pest control. To assess the exposure to organophosphates on captive B. asper, an experiment using chlorpyrifos and butyrylcholinesterase (BChE), as a biomarker was conducted. In addition to BChE, hematology, aspartate aminotransferase (AST), total proteins (TP) and albumin were measured after exposure. Different concentrations of chlorpyrifos were used in Group A (0.1%) and B (1%), while the Control Group received distilled water; each group was composed of 5 snakes. Values of BChE, AST, TP, and albumin were measured before exposure, and at 6, 12, 24, 196, 360 and 528 h post-exposure. Hematology values were measured after 24 h post-exposure. As result, an important variation between subjects in all groups before exposure was obtained. Moreover, BChE activity showed 37% inhibition of Group A when compared to Control Group at 12 h post-exposure, and a higher inhibition of Group B (97%) related to Control Group, at 6 h post-exposure. Recovery of BChE occurred towards 528 h, never reaching initial values. Despite some variation in the rest of parameters used, a marked relative lymphopenia and monocytosis occurred at 24 h, assuming stress as the main cause.

Bothrops jararaca accessory venom gland is an ancillary source of toxins to the snake.

In Viperidae snakes, it has been attributed to the main venom gland, a component of the venom gland apparatus, the function of synthesizing all venom toxins and storing them inside a basal-central lumen. However, the role of the accessory gland is still unknown. Here, we analyzed the proteome and the transcriptome of the accessory gland during venom production and secretion cycle. We showed that the accessory gland expresses and synthesizes toxins that are similar to those produced by the main venom gland such as C-type lectin/C-type lectin-like proteins, metalloproteinase, phospholipase A2, cysteine rich secretory protein, nerve growth factor, vascular endothelial growth factor, serine proteinase, and l-amino acid oxidase. Our data have shown that toxin synthesis in the accessory gland is asynchronous when compared to the same process in the venom gland. Moreover, this gland also expresses inhibitors of venom phospholipases A2 and metalloproteinases. Transcriptome analysis showed that the transcripts that correspond to toxins in the accessory gland have a good correlation to the main venom gland transcripts. Therefore, it is proposed that the accessory gland is an ancillary source of toxins to the snake, and provides inhibitors that could control venom toxicity (and integrity) during storage. SIGNIFICANCE: In this study, we propose that the accessory venom gland acts as an important ancillary source of toxins to the snake, in lieu of a depleted main venom gland, and provides inhibiting agents that control venom toxicity (and integrity) during its storage.