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At least 19 recordsLinked to original sources

PubMed2006

Lachesis muta (Viperidae) cDNAs reveal diverging pit viper molecules and scaffolds typical of cobra (Elapidae) venoms: implications for snake toxin repertoire evolution.

Efforts to describe toxins from the two major families of venomous snakes (Viperidae and Elapidae) usually reveal proteins belonging to few structural types, particular of each family. Here we carried on an effort to determine uncommon cDNAs that represent possible new toxins from Lachesis muta (Viperidae). In addition to nine classes of typical toxins, atypical molecules never observed in the hundreds of Viperidae snakes studied so far are highly expressed: a diverging C-type lectin that is related to Viperidae toxins but appears to be independently originated; an ohanin-like toxin, which would be the third member of the most recently described class of Elapidae toxins, related to human butyrophilin and B30.2 proteins; and a 3FTx-like toxin, a new member of the widely studied three-finger family of proteins, which includes major Elapidae neurotoxins and CD59 antigen. The presence of these common and uncommon molecules suggests that the repertoire of toxins could be more conserved between families than has been considered, and their features indicate a dynamic process of venom evolution through molecular mechanisms, such as multiple recruitments of important scaffolds and domain exchange between paralogs, always keeping a minimalist nature in most toxin structures in opposition to their nontoxin counterparts.

Amino Acid Sequence↗

PubMed1997

Prothrombin and factor X activator activities in the venoms of Viperidae snakes.

A Ca(2+)-dependent prothrombin activator, carinactivase-1 (CA-1), was previously found in the venom of Echis carinatus leucogaster. In the present study, the activities of CA-1-like enzymes were screened in the venoms of various Viperidae snakes. The addition of 1 mM Ca2+ ions to the venoms of only Echis snakes in Viperidae produced considerably high prothrombin activator activity, indicating that only the Echis snake venoms contain not only the Ca(2+)-independent prothrombin activator, ecarin, but also Ca(2+)-dependent activator(s). CA-1-like activators and ecarin in the venom of each Echis snake were efficiently separated by Blue Sepharose column chromatography. The venoms of the various Viperidae snakes were also examined for factor X activator activity. The venoms of genera Daboia, Vipera, Cerastes, Echis, Calloselasma and Bothrops contained factor X activator activity in the presence of Ca2+ ions. Cerastes cerastes and Calloselasma rhodostoma venoms also had Ca(2+)-independent factor X activator activity.

Animals↗

PubMed1996

Enzymatic activities of some snake venoms from families Elapidae and Viperidae.

Alkaline phosphomonoesterase, phosphodiesterase, L-amino acid oxidase, hyaluronidase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A2 and proteinase activities were determined in eight snake venoms, including three from sea snake, of families Elapidae and Viperidae from Pakistan. The species includes three sea snakes Hydrophis cyanocinctus, Enhydrina schsitosa, Microcephalophis gracilis gracilis and two land snakes Naja naja naja, Bungarus caeruleus of family Elapidae while three land snakes Vipera russelli russelli, Echis carinatus and Eristocophis macmahoni of family Viperidae. The venoms of family Elapidae are characterized by low levels to traces of proteinase, L-amino acid oxidase and arginine ester hydrolase activities with the exception of Naja naja naja and a moderate to high levels of phospholipase A2 activities. The venoms of family Viperidae, on the other hand, are characterized by the presence of moderate to high levels of 5'-nucleotidase, proteinase, phosphodiesterase and phosphomonoesterase activities.

Journal Article↗

PubMed2003

Inhibition of hemorrhagic and edematogenic activities of snake venoms by a broad-spectrum protease inhibitor, murinoglobulin; the effect on venoms from five different genera in Viperidae family.

In order to obtain basic data on the effect of broad-spectrum protease inhibitor against local symptoms of Viperidae snake envenomation, inhibitory capacity of rat murinoglobulin on local hemorrhagic and edematogenic activities of venoms from Crotalus atrox, Bothrops jararaca, Lachesis muta muta, Trimeresurus flavoviridis and Echis carinatus sochureki were examined. Murinoglobulin, pre-incubated with the crude venoms at 37 degrees C for 15 min, inhibited hemorrhagic activity of all five venoms to various extents. The activity of C. atrox was almost completely inhibited at the murinoglobulin/venom ratio (w/w) of 20. The activity of B. jararaca, Lachesis muta muta and T. flavoviridis venoms was considerably inhibited at the ratio of 20 (77.2, 80.0 and 86.2% inhibition, respectively), however some of the activity still remained even at the ratio of 40 (84.2, 79.8 and 86.2% inhibition, respectively). Among the five venoms, E. c. sochureki venom is quite resistant to murinoglobulin treatment and statistically significant inhibition was only found at the ratio of 40 (64.1% inhibition). Fibrinolytic and gelatinase activities were more susceptible to murinoglobulin inhibition. The treatment at the ratios of 10 and 20 almost completely inhibited respectively the fibrinolytic and the gelatinase activities of all the venoms. Murinoglobulin treatment also significantly inhibited the edematogenic activity of L. muta muta, T. flavoviridis and Echis carinatus sochureki. The treatment of murinoglobulin at the ratio of 40 considerably suppressed the swelling up to 60 min after subcutaneous injection of L. muta muta and E. c. sochureki venoms, and up to 30 min after T. flavoviridis venom injection. Murinoglobulin is a potent inhibitor against local effects of multiple snake venoms in Viperidae family.

Animals↗

PubMed1997

Bov-B long interspersed repeated DNA (LINE) sequences are present in Vipera ammodytes phospholipase A2 genes and in genomes of Viperidae snakes.

Ammodytin L is a myotoxic Ser49 phospholipase A2 (PLA2) homologue, which is tissue-specifically expressed in the venom glands of Vipera ammodytes. The complete DNA sequence of the gene and its 5' and 3' flanking regions has been determined. The gene consists of five exons separated by four introns. Comparative analysis of the ammodytin L and ammodytoxin C genes shows that all intron and flanking sequences are considerably more conserved (93-97%) than the mature protein-coding exons. The pattern of nucleotide substitutions in protein-coding exons is not random but occurs preferentially on the first and the second positions of codons, which suggests positive Darwinian evolution for a new function. An Ruminantia specific ART-2 retroposon, recently recognised as a 5'-truncated Bov-B long interspersed repeated DNA (LINE) sequence, was identified in the fourth intron of both genes. This result suggests that ammodytin L and ammodytoxin C genes are derived by duplication of a common ancestral gene. The phylogenetic distribution of Bov-B LINE among vertebrate classes shows that, besides the Ruminantia, it is limited to Viperidae snakes (Vipera ammodytes, Vipera palaestinae, Echis coloratus, Bothrops alternatus, Trimeresurus flavoviridis and Trimeresurus gramineus). The copy number of the 3' end of Bov-B LINE in the Vipera ammodytes genome is between 62,000 and 75,000. The absence of Bov-B LINE at orthologous positions in other snake PLA2 genes indicates that its retrotransposition in the V. ammodytes PLA2 gene locus has occurred quite recently, about 5 My ago. The amplification of Bov-B LINEs in snakes may have occurred before the divergence of the Viperinae and Crotalinae subfamilies. Due to its wide distribution in Viperidae snakes it may be a valuable phylogenetic marker. The neighbor-joining phylogenetic tree shows two clusters of truncated Bov-B LINE, a Bovidae and a snake cluster, indicating an early horizontal transfer of this transposable element.

Animals↗

PubMed2004

Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae).

Pitvipers (Viperidae: Crotalinae) possess thermal radiation receptors, the facial pits, which allow them to detect modest temperature fluctuations within their environments. It was previously thought that these organs were used solely to aid in prey acquisition, but recent findings demonstrated that western diamondback rattlesnakes (Crotalus atrox) use them to direct behavioral thermoregulation, suggesting that facial pits might be general purpose organs used to drive a suite of behaviors. To investigate this further, we conducted a phylogenetic survey of viperine thermoregulatory behavior cued by thermal radiation. We assessed this behavior in 12 pitviper species, representing key nodes in the evolution of pitvipers and a broad range of thermal environments, and a single species of true viper (Viperidae: Viperinae), a closely related subfamily of snakes that lack facial pits but possess a putative thermal radiation receptor. All pitviper species were able to rely on their facial pits to direct thermoregulatory movements, while the true viper was unable to do so. Our results suggest that thermoregulatory behavior cued by thermal radiation is a universal role of facial pits and probably represents an ancestral trait among pitvipers. Further, they establish behavioral thermoregulation as a plausible hypothesis explaining the evolutionary origin of the facial pit.

Animals↗

PubMed2003

Somatic pairing, endomitosis and chromosome aberrations in snakes (Viperidae and Colubridae).

The positioning of macrochromosomes of Bothrops jararaca and Bothrops insularis (Viperidae) was studied in undistorted radial metaphases of uncultured cells (spermatogonia and oogonia) not subjected to spindle inhibitors. Colchicinized metaphases from uncultured (spleen and intestine) and cultured tissues (blood) were also analyzed. We report two antagonic non-random chromosome arrangements in untreated premeiotic cells: the parallel configuration with homologue chromosomes associated side by side in the metaphase plate and the antiparallel configuration having homologue chromosomes with antipolar distribution in the metaphase ring. The antiparallel aspect also appeared in colchicinized cells. The spatial chromosome arrangement in both configurations is groupal size-dependent and maintained through meiosis. We also describe, in untreated gonia cells, endomitosis followed by reductional mitosis which restores the diploid number. In B. jararaca males we observed that some gonad regions present changes in the meiotic mechanism. In this case, endoreduplicated cells segregate the diplochromosomes to opposite poles forming directly endoreduplicated second metaphases of meiosis with the suppression of first meiosis. By a successive division, these cells form nuclei with one set of chromosomes. Chromosome doubling in oogonia is known in hybrid species and in parthenogenetic salamanders and lizards. This species also presented chromosome rearrangements leading to aneuploidies in mitosis and meiosis. It is suggested that somatic pairing, endomitosis, meiotic alterations, and chromosomal aberrations can be correlated processes. Similar aspects of nuclei configurations, endomitosis and reductional mitosis were found in other Viperidae and Colubridae species.

Animals↗

PubMed2003

Proteomics of snake venoms from Elapidae and Viperidae families by multidimensional chromatographic methods.

Snake venoms contain a large number of biologically active substances and the venom components are very useful for pharmaceutical applications. Our goal is to separate and identify components of snake venoms in ten snake species from the Elapidae and Viperidae families using multidimensional chromatographic methods. The multidimensional chromatographic methods include reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), lab-on-a-chip, two-dimensional electrophoresis (2-DE), and mass spectrometry. The venoms of eight snake species demonstrated major differences in hydrophobicity, molecular weight separations, and 2-DE protein distribution patterns. The 2-DE images showed major differences between families, within each family and even between the same species. Venoms of the Elapidae family showed many basic proteins with a wide range of molecular weights, while venoms of the Viperidae family showed wide ranges of pI and molecular weights, especially for Trimeresurus sp. The multidimensional chromatographic methods revealed specific differences in venom proteins intra-species as well as between species and families. We have isolated and identified proteins that may be unique for each species for further studies in the proteome of snake venoms and their potentially use in the pharmaceutical applications.

Animals↗

PubMed1989

Cross reactivity of mono- and polyvalent antivenoms with Viperidae and Crotalidae snake venoms.

The lethal, local and defibrinating effects of two African Viperidae and four Crotalidae were assayed. Two commercial antivenoms (Behringwerke Nord Africa and Wyeth anticrotalic) and gamma-globulins from hyperimmune rabbit serum were tested for their ability to neutralize the toxic effects of the venoms. Cross neutralization of the lethal effect (antiviperidae antivenom against Crotalidae venom and vice versa) was evident with Behringwerke against Crotalidae as well as with Wyeth against Viperidae. No cross-reactivity was observed with monovalent antivenoms. Practically complete cross-reactivity was observed with polyvalent, but less with monovalent antivenoms in the neutralization of skin hemorrhage. The local effect was neutralized to 0-20% if the antivenom was mixed with the venom. An i.v. injection of antivenom had no effect after intradermally injected venom. Only Echis and Bothrops venoms cause defibrination in vivo. The ability of the two polyvalent antivenoms to neutralize defibrination was very weak. One half milliliter of antivenom neutralized 1 microgram (Echis carinatus) or 10 micrograms (Bothrops asper) of defibrinating venom if injected simultaneously. If antivenom was administered 3 hr after the venom, the fibrinogen level increased to about 50% of the normal values after 24 hr. Cross-reactivity in the neutralization of the defibrinating activity was observed with both polyvalent antivenoms.

Animals↗

PubMed1989

[The structure and ultrastructure of the pulp in Vipera aspis (Viperidae)].

The present paper using classical and transmission electron microscopy brings the first data on the pulp of the fangs of Viperidae (poisonous serpents with terrestrial or semi-aquatic habits). The pulp of the fangs of Viperidae shows a poor collagen and fibroblast content and a high developed vascular system. The odontoblasts are polarized, with a high organelle content. The interconnections are constituted of lateral "gap junction" systems. At a late secretion stage, the odontoblastic processes show a poor cytoplasm, mainly constituted of microfilaments.

Animals↗

PubMedDate not supplied

Analysis of lectin-bound glycoproteins in snake venom from the Elapidae and Viperidae families.

This paper describes an efficient method of studying the glycoproteins found in snake venom. The glycosylation profiles of the Elapidae and Viperidae snake families were analyzed using FITC-labeled lectin glycoconjugates. The Con A-agarose affinity enrichment technique was used to fractionate glycoproteins from the N. naja kaouthia venom. The results revealed a large number of Con A binding glycoproteins, most of which have moderate to high molecular weights. To identify the proteins, the isolated glycoprotein fractions were subjected to two-dimensional electrophoresis and MALDI-TOF MS. Protein sequences were compared with published protein databases to determine for their biological functions.

Animals↗

PubMed2000

[Phylogenetic relationships among Viperidae, Crotalinae based on mitochondrial 12S rRNA sequence variations].

This paper analyzed the phylogenetic relationships and classification of pit vipers (Viperidae, Crotalinae) based on mitochondrial 12S rRNA gene sequence variations. We have sequenced mtDNA 12S rRNA gene about 370 bp fragment from Gloydius saxatilis Emelianov, Gloydius shedaoensis Zhao, Gloydius ussurriensis (Emelianov), Trimeresurus stejnegeri Schmidt and Deinagkistrodon acutus, Gloydius brevicaudus (Stejneger) from two different localities, respectively. Combined with the sequence of Dinodon semicarinatus from GenBank, we have constructed two molecular phylogenetic trees using both Maximum-parsimony analysis and Neighbor-joining. Our results support the following conclusions: (1) Deinagkistrodon is a valid genus; (2) we also discussed the origin of Gloydius shedaoensis and showed it is a subspecies of Gloydius saxatilis; (3) Gloydius brevicaudsu and Gloydius ussurriensis are classified two species.

Animals↗

PubMedDate not supplied

Membrane-perturbing activity of Viperidae myotoxins: an electrostatic surface potential approach to a puzzling problem.

Phospholipase-like myotoxins are a class of proteins present in Viperidae venom. Despite the high level of amino acid and structural homology with soluble phospholipases A(2), myotoxins are devoid of enzymatic activity and share cytolytic activity by means of a totally unknown mechanism involving the lipid bilayer perturbation. The distribution of electrostatic surface potentials of four myotoxins and seven phospholipases A(2) has been compared. The charge distribution is similar in all active non-cytolytic phospholipases with a strongly positive side corresponding to the domain interacting with the micellar substrate and with the opposite side negatively charged. In contrast, all myotoxins examined are positively charged on both sides. Myotoxin III, the only known example of a myotoxin sharing enzymatic activity, displays the same electrostatic surface potential as other related toxins. Using liposomes made with non-hydrolysable phospholipids, we demonstrate that myotoxin III perturbs the lipid bilayer like other myotoxins. Based on these results, a molecular model for myotoxin-membrane perturbing activity is proposed. In this model, potential double-face binding of myotoxic phospholipases A(2) to lipid surfaces could trigger a lipid bilayer destabilization and could generate a stable fusion pore, probably because of the presence of hydrophobic moieties that flank the cationic sites.

Cell Membrane Permeability↗

PubMed1997

Annual cycle of plasma testosterone in male copperheads, Agkistrodon contortrix (Serpentes, Viperidae): relationship to timing of spermatogenesis, mating, and agonistic behavior.

Reproductive cycles of the majority of squamate reptiles remain undescribed. Few studies are available on seasonal patterns of circulating steroid hormones in snakes. The goal of this study was to document the annual cycle of plasma testosterone (T) in male copperheads Agkistrodon contortrix, a North American pitviper (Serpentes, Viperidae). Two experimental conditions were used in this laboratory study. One condition (repeat-test group) consisted of 10 adult males that were sampled once each month for 11 months. The other condition (single-test groups) consisted of 10 groups each with 5 males (N = 50), and each male was tested a single time. The single-test condition was used to evaluate whether or not repeated handling and sampling affected T levels. The study was conducted from February-December, 1992. A well-defined seasonal pattern of plasma T levels was detected; patterns were similar under both experimental conditions with the exception that the repeat-test group had slightly lower levels. Levels of T were lowest (baseline) in April-May, increased in early summer (June), and were highest in late summer (August). Thereafter, T levels declined up to the time of hibernation (early November) and changed little during hibernation (November-January). Upon emergence from hibernation in late winter (February), T levels increased sharply from February to March and then decreased from March to April. The results are discussed in the context of timing of spermatogenesis, mating, and male agonistic behavior.

Agkistrodon↗

PubMed1985

Chromogenic proteinase substrates as possible tools in the characterization of Crotalidae and Viperidae snake venoms.

Proteinase activities have been determined photometrically in 25 different Crotalidae and Viperidae snake venoms by using five different chromogenic proteinase substrates. The activity profiles obtained by listing the identity numbers of substrates hydrolyzed by the venoms in a decreasing potency order remained quite stable within a given snake population. Submission of a venom to various physical and chemical treatments did not alter its activity profile. It is therefore concluded that this simple method of determining proteinase activities could be of help in snake venom characterization, as well as in studying the influence of metallic ions and inhibitors of snake venom proteinases.

Animals↗

PubMedDate not supplied

Post-fight levels of plasma lactate and corticosterone in male copperheads, Agkistrodon contortrix (Serpentes, Viperidae): differences between winners and losers.

During the mating seasons (late summer and spring), male copperheads (Agkistrodon contortrix; Serpentes, Viperidae) engage in aggressive physical interactions for priority of access to females. These fights generally involve two individuals and are characterized by prominent vertical displays, a high degree of physical contact, and the absence of biting. Ritualized aggression does not occur in females. Although intrasexual aggression in conspecifics has obvious energetic costs (e.g., lactate accumulation) that can affect subsequent behavior, few studies have addressed these costs in reptiles, and no studies have examined snakes. Moreover, recent studies suggest psychoneuroendocrine (catecholamines, glucocorticoids) regulation of metabolism during and following aggressive episodes. There were three main questions addressed in this study. Do winners and losers of staged, pair-wise encounters show differences in post-fight (60-min) levels of plasma lactate and corticosterone (CORT)? Are levels of plasma lactate correlated with levels of plasma CORT? Is fight duration correlated with levels of plasma lactate and CORT? Two different control groups (cage and arena) were used. Body length, body mass, duration of fighting, and season of testing were not correlated with levels of plasma lactate and CORT. At 60-min post-fight, losers had significantly higher levels of mean plasma lactate and CORT when compared to levels in winners and controls, and there were no significant differences between winners and controls. From our results, we suggest the following conclusions. First, elevated levels of CORT in losers, but not winners, result from psychoneuroendocrine factors rather than simple exercise. Second, elevated levels of CORT in losers retard metabolic recovery resulting in higher lactate levels in losers, whereas winners return to pre-fight levels within 60-min post-fight. Last, the CORT response has a net negative effect on metabolic recovery and may be implicated in the protracted suppression of aggressive behavior in losers.

Aggression↗

PubMed1986

Experimental transmission of Caryospora simplex (Apicomplexa: Eimeriidae) to Palestine vipers, Vipera xanthina palestinae (Serpentes: Viperidae).

Four littermate, laboratory-reared Palestine vipers, Vipera xanthina palestinae (#149, #150, #151, #152) (Serpentes: Viperidae) were used to determine modes by which Caryospora simplex (Apicomplexa: Eimeriidae) could be transmitted to snakes. Viper #149 was inoculated orally by stomach tube with 5.0 X 10(4) sporulated oocysts of C. simplex obtained from the feces of an Ottoman viper, V. x. xanthina and began passing unsporulated oocysts of C. simplex 121 days post-inoculation (DPI). Viper #150 was fed five mice that had been inoculated orally greater than or equal to 25 days previously with 5.0 X 10(4) sporulated oocysts of C. simplex and it began passing unsporulated oocysts of C. simplex 33 days after being fed the first two of five mice. Viper #151 was inoculated orally with sporulated oocysts of C. simplex obtained from viper #150 and began passing oocysts 52 DPI. Viper #152 served as an uninoculated control and did not pass oocysts of any species of coccidian. This study demonstrates that snake/snake and mouse/snake transmission of C. simplex readily occurs.

Animals↗

PubMed2002

A taxonomic bibliography of the South American snakes of the Crotalus durissus complex (Serpentes, Viperidae).

A survey is made of the taxonomic literature on South American rattlesnakes (genus Crotalus, family Viperidae). Two main areas are emphasized: the attribution of the names proposed in the eighteenth century by Linnaeus and Laurenti, and the current scheme of division in subspecies. The attribution of names is examined based on the original descriptions and on relevant previous and contemporary literature. The presently adopted scheme, proposed by Klauber (1941, 1972) is found not entirely satisfactory, but reasonable enough--besides being hallowed by use. The scheme of geographical differentiation, intrinsically important and with broad practical implications (differentiation of the venom) is found to be the culmination of a long series of deficient analyses, and in urgent need of proper investigation.

Animals↗