Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ENZYMES. They include palytoxin, sarcophine, and anthopleurine.
A phylum of radially symmetrical invertebrates characterized by possession of stinging cells called nematocysts. It includes the classes ANTHOZOA; CUBOZOA; HYDROZOA, and SCYPHOZOA. Members carry CNIDARIAN VENOMS.
A class in the phylum CNIDARIA which alternates between polyp and medusa forms during their life cycle. There are over 2700 species in five orders.
The order Actiniaria, in the class ANTHOZOA, comprised of large, solitary polyps. All species are carnivorous.
Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.
A genus of freshwater polyps in the family Hydridae, order Hydroida, class HYDROZOA. They are of special interest because of their complex organization and because their adult organization corresponds roughly to the gastrula of higher animals.
A double-walled capsule found in jellyfish and other CNIDARIA whose functions include prey capture, defense, locomotion, and attachment. Nematocysts contain toxic CNIDARIAN VENOMS which are injected into the victim via a barbed tubule.
Venoms obtained from Apis mellifera (honey bee) and related species. They contain various enzymes, polypeptide toxins, and other substances, some of which are allergenic or immunogenic or both. These venoms were formerly used in rheumatism to stimulate the pituitary-adrenal system.
Poisonous animal secretions forming fluid mixtures of many different enzymes, toxins, and other substances. These substances are produced in specialized glands and secreted through specialized delivery systems (nematocysts, spines, fangs, etc.) for disabling prey or predator.
Venoms from snakes of the genus Naja (family Elapidae). They contain many specific proteins that have cytotoxic, hemolytic, neurotoxic, and other properties. Like other elapid venoms, they are rich in enzymes. They include cobramines and cobralysins.
Venoms from SNAKES of the viperid family. They tend to be less toxic than elapid or hydrophid venoms and act mainly on the vascular system, interfering with coagulation and capillary membrane integrity and are highly cytotoxic. They contain large amounts of several enzymes, other factors, and some toxins.
Venoms produced by the wasp (Vespid) family of stinging insects, including hornets; the venoms contain enzymes, biogenic amines, histamine releasing factors, kinins, toxic polypeptides, etc., and are similar to bee venoms.
The class of true jellyfish, in the phylum CNIDARIA. They are mostly free-swimming marine organisms that go through five stages in their life cycle and exhibit two body forms: polyp and medusa.
Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.
Venoms of arthropods of the order Araneida of the ARACHNIDA. The venoms usually contain several protein fractions, including ENZYMES, hemolytic, neurolytic, and other TOXINS, BIOLOGICAL.
Phylum of marine colenterates characterized by eight comb rows of fused cilia on the body surface. In contrast to CNIDARIA they lack stinging cells, but they are voracious predators and possess sticky cells (colloblasts) for capturing prey. Most species are transparent and many exhibit bioluminescence.
A class in the phylum CNIDARIA, comprised mostly of corals and anemones. All members occur only as polyps; the medusa stage is completely absent.
Venoms from animals of the order Scorpionida of the class Arachnida. They contain neuro- and hemotoxins, enzymes, and various other factors that may release acetylcholine and catecholamines from nerve endings. Of the several protein toxins that have been characterized, most are immunogenic.
Venoms from animals of the phylum Arthropoda. Those most investigated are from scorpions and spiders of the class Arachnidae and from ant, bee, and wasp families of the Insecta order Hymenoptera. The venoms contain protein toxins, enzymes, and other bioactive substances and may be lethal to man.
Flagellate EUKARYOTES, found mainly in the oceans. They are characterized by the presence of transverse and longitudinal flagella which propel the organisms in a rotating manner through the water. Dinoflagellida were formerly members of the class Phytomastigophorea under the old five kingdom paradigm.
A phylum of primitive invertebrate animals that exemplify a simple body organization. Trichoplax adhaerens is considered a key species for early metazoan evolution.
The class of box jellyfish, in the phylum CNIDARIA, characterized by their cube shape, and considered the most venomous jellyfish.
The relationships of groups of organisms as reflected by their genetic makeup.
Single-celled, aquatic endoparasitic worms that are currently considered belonging to the phylum CNIDARIA. They have a complex life cycle and parasitize a wide range of hosts including FISHES; ANNELIDA; and BRYOZOA.
A genus of poisonous snakes of the VIPERIDAE family. About 50 species are known and all are found in tropical America and southern South America. Bothrops atrox is the fer-de-lance and B. jararaca is the jararaca. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p336)
Antisera used to counteract poisoning by animal VENOMS, especially SNAKE VENOMS.
Animals that have no spinal column.
Venoms produced by FISHES, including SHARKS and sting rays, usually delivered by spines. They contain various substances, including very labile toxins that affect the HEART specifically and all MUSCLES generally.
The phylum of sponges which are sessile, suspension-feeding, multicellular animals that utilize flagellated cells called choanocytes to circulate water. Most are hermaphroditic. They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. They are a source of ALKALOIDS; STEROLS; and other complex molecules useful in medicine and biological research.
Venoms from the superfamily Formicoidea, Ants. They may contain protein factors and toxins, histamine, enzymes, and alkaloids and are often allergenic or immunogenic.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.
A family of extremely venomous snakes, comprising coral snakes, cobras, mambas, kraits, and sea snakes. They are widely distributed, being found in the southern United States, South America, Africa, southern Asia, Australia, and the Pacific Islands. The elapids include three subfamilies: Elapinae, Hydrophiinae, and Lauticaudinae. Like the viperids, they have venom fangs in the front part of the upper jaw. The mambas of Africa are the most dangerous of all snakes by virtue of their size, speed, and highly toxic venom. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p329-33)
Venoms from mollusks, including CONUS and OCTOPUS species. The venoms contain proteins, enzymes, choline derivatives, slow-reacting substances, and several characterized polypeptide toxins that affect the nervous system. Mollusk venoms include cephalotoxin, venerupin, maculotoxin, surugatoxin, conotoxins, and murexine.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Limbless REPTILES of the suborder Serpentes.
The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A genus of venomous snakes of the subfamily Crotalinae. Twelve species of this genus are found in North and Central America and Asia. Agkistrodon contortrix is the copperhead, A. piscivorus, the cottonmouth. The former is named for its russet or orange-brown color, the latter for the white interior of its mouth. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p336; Moore, Poisonous Snakes of the World, 1980, p75)
Venoms produced by frogs, toads, salamanders, etc. The venom glands are usually on the skin of the back and contain cardiotoxic glycosides, cholinolytics, and a number of other bioactive materials, many of which have been characterized. The venoms have been used as arrow poisons and include bufogenin, bufotoxin, bufagin, bufotalin, histrionicotoxins, and pumiliotoxin.
Organs and other anatomical structures of non-human vertebrate and invertebrate animals.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.
A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
Synthetic analogs of NUCLEIC ACIDS composed of morpholine ring derivatives (MORPHOLINES) linked by phosphorodimidates. One standard DNA nucleic acid base (ADENINE; GUANINE; CYTOSINE; OR THYMINE) is bound to each morpholine ring.
A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.
Bites by snakes. Bite by a venomous snake is characterized by stinging pain at the wound puncture. The venom injected at the site of the bite is capable of producing a deleterious effect on the blood or on the nervous system. (Webster's 3d ed; from Dorland, 27th ed, at snake, venomous)
Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.
A genus of cone-shaped marine snails in the family Conidae, class GASTROPODA. It comprises more than 600 species, many containing unique venoms (CONUS VENOMS) with which they immobilize their prey.
A genus of snakes of the family VIPERIDAE. About 30 species are currently recognized, found in southeast Asia and adjacent island chains. The Okinawa habu frequently enters dwellings in search of rats and mice; the Chinese habu is often found in suburban and agricultural areas. They are quite irritable. (Moore: Poisonous Snakes of the World, 1980, p136)
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A portion of the animal phylum Chordata comprised of the subphyla CEPHALOCHORDATA; UROCHORDATA, and HYPEROTRETI, but not including the Vertebrata (VERTEBRATES). It includes nonvertebrate animals having a NOTOCHORD during some developmental stage.
Toxic substances from microorganisms, plants or animals that interfere with the functions of the nervous system. Most venoms contain neurotoxic substances. Myotoxins are included in this concept.
One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.
The internal fragments of precursor proteins (INternal proTEINS) that are autocatalytically removed by PROTEIN SPLICING. The flanking fragments (EXTEINS) are ligated forming mature proteins. The nucleic acid sequences coding for inteins are considered to be MOBILE GENETIC ELEMENTS. Inteins are composed of self-splicing domains and an endonuclease domain which plays a role in the spread of the intein's genomic sequence. Mini-inteins are composed of the self-splicing domains only.
Phospholipases that hydrolyze the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.
A genus of poisonous snakes of the subfamily Elapinae of the family ELAPIDAE. They comprise the kraits. Twelve species are recognized and all inhabit southeast Asia. They are considered extremely dangerous. (Moore: Poisonous Snakes of the World, 1980, p120)
Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.
A specific complex of toxic proteins from the venom of Crotalus durissus terrificus (South American rattlesnake). It can be separated into a phospholipase A and crotapotin fragment; the latter consists of three different amino acid chains, potentiates the enzyme, and is specifically neurotoxic.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
Bites and stings inflicted by insects.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
The genetic complement of MITOCHONDRIA as represented in their DNA.
A genus of snakes of the family VIPERIDAE. It is distributed in West Pakistan, most of India, Burma, Ceylon, Thailand, southeast China, Taiwan, and a few islands of Indonesia. It hisses loudly when disturbed and strikes with great force and speed. Very prolific, it gives birth to 20-60 young. This viper is the leading cause of snakebite in India and Burma. (Moore: Poisonous Snakes of the World, 1980, p127)
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.

Cellular and ionic basis for T-wave alternans under long-QT conditions. (1/271)

BACKGROUND: T-wave alternans (TWA), an ECG phenomenon characterized by beat-to-beat alternation of the morphology, amplitude, and/or polarity of the T wave, is commonly observed in the acquired and congenital long-QT syndromes (LQTS). This study examines the cellular and ionic basis for TWA induced by rapid pacing under conditions mimicking the LQT3 form of the congenital LQTS in an arterially perfused canine left ventricular wedge preparation. METHODS AND RESULTS: Transmembrane action potentials from epicardial, M, and endocardial cells and 6 to 8 intramural unipolar electrograms were simultaneously recorded together with a transmural ECG and isometric tension development. In the presence of sea anemone toxin (ATX-II; 20 nmol/L), an increase in pacing rate (from a cycle length [CL] of 500 to 400 to 250 ms) produced a wide spectrum of T-wave and mechanical alternans. Acceleration to CLs of 400 to 300 ms produced mild to moderate TWA principally due to beat-to-beat alternation of repolarization of cells in the M region. Transmural dispersion of repolarization during alternans was exaggerated during alternate beats. Acceleration to CLs of 300 to 250 ms caused more pronounced beat-to-beat alternation of action potential duration (APD) of the M cell, resulting in a reversal of repolarization sequence across the ventricular wall, leading to alternation in the polarity of the T wave. The peak of the negative T waves coincided with repolarization of the M region, whereas the end of the negative T wave coincided with the repolarization of epicardium. In almost all cases, electrical alternans was concordant with mechanical alternans. Torsade de pointes occurred after an abrupt acceleration of CL, which was associated with marked TWA. Both ryanodine and low [Ca2+]o completely suppressed alternans of the T wave, APD, and contraction, suggesting a critical role for intracellular Ca2+ cycling in the maintenance of TWA. CONCLUSIONS: Our results suggest that TWA observed at rapid rates under long-QT conditions is largely the result of alternation of the M-cell APD, leading to exaggeration of transmural dispersion of repolarization during alternate beats, and thus the potential for development of torsade de pointes. Our data also suggest that unlike transient forms of TWA that damp out quickly and depend on electrical restitution factors, the steady-state electrical and mechanical alternans demonstrated in this study appears to be largely the result of beat-to-beat alternans of [Ca2+]i.  (+info)

ATX II, a sodium channel toxin, sensitizes skeletal muscle to halothane, caffeine, and ryanodine. (2/271)

BACKGROUND: The function or expression of subtypes of the sodium ion (Na+) channel is altered in biopsies or cultures of skeletal muscle from many persons who are susceptible to malignant hyperthermia (MH). ATX II, a specific Na+ channel toxin from a sea anemone, causes delayed inactivation of the channel similar to that seen in cell cultures of MH muscle. ATX II was added to skeletal muscle to determine whether altered Na+ channel function could increase the sensitivity of normal skeletal muscle to agents (halothane, caffeine, ryanodine) to which MH muscle is hypersensitive. METHODS: Studies were performed of fiber bundles from the vastus lateralis muscle of persons who were deemed not MH susceptible (MH-) or MH susceptible (MH+) according to the MH diagnostic test and of strips of diaphragm muscle from rats. Preparations in a tissue bath containing Krebs solution were connected to a force transducer. ATX II was introduced 5 min before halothane, caffeine, or ryanodine. RESULTS: ATX II increased the magnitude of contracture to halothane in preparations from most MH-, but not MH+, human participants. After ATX II treatment, preparations from 9 of 24 MH- participants generated contractures to halothane, 3%, that were of the same magnitude as those from MH+ participants. Preparations from four of six ATX II-treated healthy participants also gave responses of the same magnitude as those of MH-susceptible participants to a graded halothane challenge (0.5-3%). The contractures to bolus doses of halothane in specimens from male participants were more than three times larger than the contractures in specimens from female participants. In rat muscle, ATX II increased the magnitude of contracture to caffeine (2 mM) and decreased the time to produce a 1-g contracture to ryanodine (1 microM). CONCLUSIONS: ATX II, which causes delayed inactivation of the Na+ channel in cell cultures similar to that reported in cultures of MH+ skeletal muscle, increased the sensitivity of normal muscle to three agents to which MH+ muscle is hypersensitive. The increased sensitivity to halothane, 3%, occurred in most (79%), but not all, MH- participants, and this effect was most evident in male participants. Therefore, abnormal function of the Na+ channel, even if it is a secondary event in MH, may contribute to a positive contracture test result for MH.  (+info)

Structural conservation of the pores of calcium-activated and voltage-gated potassium channels determined by a sea anemone toxin. (3/271)

The structurally defined sea anemone peptide toxins ShK and BgK potently block the intermediate conductance, Ca(2+)-activated potassium channel IKCa1, a well recognized therapeutic target present in erythrocytes, human T-lymphocytes, and the colon. The well characterized voltage-gated Kv1.3 channel in human T-lymphocytes is also blocked by both peptides, although ShK has a approximately 1,000-fold greater affinity for Kv1.3 than IKCa1. To gain insight into the architecture of the toxin receptor in IKCa1, we used alanine-scanning in combination with mutant cycle analyses to map the ShK-IKCa1 interface, and compared it with the ShK-Kv1.3 interaction surface. ShK uses the same five core residues, all clustered around the critical Lys(22), to interact with IKCa1 and Kv1.3, although it relies on a larger number of contacts to stabilize its weaker interactions with IKCa1 than with Kv1.3. The toxin binds to IKCa1 in a region corresponding to the external vestibule of Kv1.3, and the turret and outer pore of the structurally defined bacterial potassium channel, KcsA. Based on the NMR structure of ShK, we deduce the toxin receptor in IKCa1 to have x-y dimensions of approximately 22 A, a diameter of approximately 31 A, and a depth of approximately 8 A; we estimate that the ion selectivity lies approximately 13 A below the outer lip of the toxin receptor. These dimensions are in good agreement with those of the KcsA channel determined from its crystal structure, and the inferred structure of Kv1.3 based on mapping with scorpion toxins. Thus, these distantly related channels exhibit architectural similarities in the outer pore region. This information could facilitate development of specific and potent modulators of the therapeutically important IKCa1 channel.  (+info)

Cysteine-scanning mutagenesis of an eukaryotic pore-forming toxin from sea anemone: topology in lipid membranes. (4/271)

Equinatoxin II is a cysteineless pore-forming protein from the sea anemone Actinia equina. It readily creates pores in membranes containing sphingomyelin. Its topology when bound in lipid membranes has been studied using cysteine-scanning mutagenesis. At approximately every tenth residue, a cysteine was introduced. Nineteen single cysteine mutants were produced in Escherichia coli and purified. The accessibility of the thiol groups in lipid-embedded cysteine mutants was studied by reaction with biotin maleimide. Most of the mutants were modified, except those with cysteines at positions 105 and 114. Mutants R144C and S160C were modified only at high concentrations of the probe. Similar results were obtained if membrane-bound biotinylated mutants were tested for avidin binding, but in this case three more mutants gave a negative result: S1C, S13C and K43C. Furthermore, mutants S1C, S13C, K20C, K43C and S95C reacted with biotin only after insertion into the lipid, suggesting that they were involved in major conformational changes occurring upon membrane binding. These results were further confirmed by labeling the mutants with acrylodan, a polarity-sensitive fluorescent probe. When labeled mutants were combined with vesicles, the following mutants exhibited blue-shifts, indicating the transfer of acrylodan into a hydrophobic environment: S13C, K20C, S105C, S114C, R120C, R144C and S160C. The overall results suggest that at least two regions are embedded within the lipid membrane: the N-terminal 13-20 region, probably forming an amphiphilic helix, and the tryptophan-rich 105-120 region. Arg144, Ser160 and residues nearby could be involved in making contacts with lipid headgroups. The association with the membrane appears to be unique and different from that of bacterial pore-forming proteins and therefore equinatoxin II may serve as a model for eukaryotic channel-forming toxins.  (+info)

Increased hindrance on the chiral carbon atom of mexiletine enhances the block of rat skeletal muscle Na+ channels in a model of myotonia induced by ATX. (5/271)

1 The antiarrhythmic drug mexiletine (Mex) is also used against myotonia. Searching for a more efficient drug, a new compound (Me5) was synthesized substituting the methyl group on the chiral carbon atom of Mex by an isopropyl group. Effects of Me5 on Na+ channels were compared to those of Mex in rat skeletal muscle fibres using the cell-attached patch clamp method. 2 Me5 (10 microM) reduced the maximal sodium current (INa) by 29.7+/-4.4 % (n=6) at a frequency of stimulation of 0.3 Hz and 65.7+/-4.4 % (n=6) at 1 Hz. At same concentration (10 microM), Mex was incapable of producing any effect (n=3). Me5 also shifted the steady-state inactivation curves by -7. 9+/-0.9 mV (n=6) at 0.3 Hz and -12.2+/-1.0 mV (n=6) at 1 Hz. 3 In the presence of sea anemone toxin II (ATX; 5 microM), INa decayed more slowly and no longer to zero, providing a model of sodium channel myotonia. The effects of Me5 on peak INa were similar whatever ATX was present or not. Interestingly, Me5 did not modify the INa decay time constant nor the steady-state INa to peak INa ratio. 4 Analysis of ATX-induced late Na+ channel activity shows that Me5 did not affect mean open times and single-channel conductance, thus excluding open channel block property. 5 These results indicate that increasing hindrance on the chiral atom of Mex increases drug potency on wild-type and ATX-induced noninactivating INa and that Me5 might improve the prophylaxis of myotonia.  (+info)

Mapping the functional anatomy of BgK on Kv1.1, Kv1.2, and Kv1.3. Clues to design analogs with enhanced selectivity. (6/271)

BgK is a peptide from the sea anemone Bunodosoma granulifera, which blocks Kv1.1, Kv1.2, and Kv1.3 potassium channels. Using 25 analogs substituted at a single position by an alanine residue, we performed the complete mapping of the BgK binding sites for the three Kv1 channels. These binding sites included three common residues (Ser-23, Lys-25, and Tyr-26) and a variable set of additional residues depending on the particular channel. Shortening the side chain of Lys-25 by taking out the four methylene groups dramatically decreased the BgK affinity to all Kv1 channels tested. However, the analog K25Orn displayed increased potency on Kv1.2, which makes this peptide a selective blocker for Kv1.2 (K(D) 50- and 300-fold lower than for Kv1.1 and Kv1.3, respectively). BgK analogs with enhanced selectivity could also be made by substituting residues that are differentially involved in the binding to some of the three Kv1 channels. For example, the analog F6A was found to be >500-fold more potent for Kv1.1 than for Kv1.2 and Kv1.3. These results provide new information about the mechanisms by which a channel blocker distinguishes individual channels among closely related isoforms and give clues for designing analogs with enhanced selectivity.  (+info)

Structure-function studies of tryptophan mutants of equinatoxin II, a sea anemone pore-forming protein. (7/271)

Equinatoxin II (EqtII) is a eukaryotic cytolytic toxin that avidly creates pores in natural and model lipid membranes. It contains five tryptophan residues in three different regions of the molecule. In order to study its interaction with the lipid membranes, three tryptophan mutants, EqtII Trp(45), EqtII Trp(116/117) and EqtII Trp(149), were prepared in an Escherichia coli expression system [here, the tryptophan mutants are classified according to the position of the remaining tryptophan residue(s) in each mutated protein]. They all possess a single intrinsic fluorescent centre. All mutants were less haemolytically active than the wild-type, although the mechanism of erythrocyte damage was the same. EqtII Trp(116/117) resembles the wild-type in terms of its secondary structure content, as determined from Fourier-transform infrared (FTIR) spectra and its fluorescent properties. Tryptophans at these two positions are buried within the hydrophobic interior of the protein, and are transferred to the lipid phase during the interaction with the lipid membrane. The secondary structure of the other two mutants, EqtII Trp(45) and EqtII Trp(149), was altered to a certain extent. EqtII Trp(149) was the most dissimilar from the wild-type, displaying a higher content of random-coil structure. It also retained the lowest number of nitrogen-bound protons after exchange with (2)H(2)O, which might indicate a reduced compactness of the molecule. Tryptophans in EqtII Trp(45) and EqtII Trp(149) were more exposed to water, and also remained as such in the membrane-bound form.  (+info)

Differential effects of beta-adrenergic agonists and antagonists in LQT1, LQT2 and LQT3 models of the long QT syndrome. (8/271)

OBJECTIVES: To define the cellular mechanisms responsible for the development of life-threatening arrhythmias in response to sympathetic activity in the congenital and acquired long QT syndromes (LCQTS). METHODS: Transmembrane action potentials (AP) from epicardial (EPI), M and endocardial (ENDO) cells and a transmural electrocardiogram were simultaneously recorded from an arterially perfused wedge of canine left ventricle. We examined the effect of beta-adrenergic agonists and antagonists on action potential duration (APD90), transmural dispersion of repolarization (TDR) and the development of Torsade de Pointes (TdP) in models of LQT1, LQT2 and LQT3 forms of LQTS. RESULTS: I(Ks) block with chromanol 293B (LQT1) homogeneously prolonged APD90 of the three cell types without increasing TDR. Addition of isoproterenol prolonged QT and APD90 of M but abbreviated that of EPI and ENDO, causing a persistent increase in TDR; Torsade de Pointes developed or could be induced only in the presence of isoproterenol. I(Kr) block with d-sotalol (LQT2) and augmentation of late I(Na) with ATX-II (LQT3) prolonged APD90 of M more than EPI and ENDO, causing increases in QT and TDR. TdP developed in the absence of isoproterenol. In LQT2 isoproterenol initially prolonged, then abbreviated, the APD90 of M but always abbreviated EPI, thus transiently increasing TDR and the incidence of TdP. In LQT3, isoproterenol always abbreviated APD90 of the three cell types, causing a persistent decrease in TDR and suppression of TdP. The arrhythmogenic as well as protective actions of isoproterenol were reversed by propranolol. CONCLUSIONS: Our data suggest that beta-adrenergic stimulation induces TdP by increasing transmural dispersion of repolarization in LQT1 and LQT2 but suppresses TdP by decreasing dispersion in LQT3. The data indicate that beta-blockers are protective in LQT1 and LQT2 but may facilitate TdP in LQT3.  (+info)

Cnidarian Venoms: Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ENZYMES. They include palytoxin, sarcophine, and anthopleurine.
The human ether-à-go-go channel (hEag1 or KV10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. Peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs. Here, we report the activity-guided purification and electrophysiological characterization of a novel KV10.1 inhibitor from the sea anemone Anthopleura elegantissima. Purified sea anemone fractions were screened for inhibitory activity on KV10.1 by measuring whole-cell currents as expressed in Xenopus laevis oocytes using the two-microelectrode voltage clamp technique. Fractions that showed activity on Kv10.1 were further purified by RP-HPLC. The amino acid sequence of the peptide was determined by a combination of MALDI- LIFT-TOF/TOF MS/MS and CID-ESI-FT-ICR MS/MS and showed a high similarity with APETx1 and APETx3 and was therefore named APETx4. Subsequently, the peptide was electrophysiologically characterized on KV10.1. The
The human ether-à-go-go channel (hEag1 or KV10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. Peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs. Here, we report the activity-guided purification and electrophysiological characterization of a novel KV10.1 inhibitor from the sea anemone Anthopleura elegantissima. Purified sea anemone fractions were screened for inhibitory activity on KV10.1 by measuring whole-cell currents as expressed in Xenopus laevis oocytes using the two-microelectrode voltage clamp technique. Fractions that showed activity on Kv10.1 were further purified by RP-HPLC. The amino acid sequence of the peptide was determined by a combination of MALDI- LIFT-TOF/TOF MS/MS and CID-ESI-FT-ICR MS/MS and showed a high similarity with APETx1 and APETx3 and was therefore named APETx4. Subsequently, the peptide was electrophysiologically characterized on KV10.1. The
1. Feeding can be initiated in Anemonia sulcata by mechanical, chemical or electrical stimulation of the tentacles provided the stimulus sets up sufficiently prolonged excitation. Owing to rapid adaptation, mechanical stimuli rarely set up enduring excitation and inert objects are therefore usually rejected. Chemical stimuli set up prolonged excitation and food objects are therefore usually accepted. A series of electrical stimuli can produce rejection or feeding according to whether it is brief or prolonged.. 2. The sensitivity of the tentacles varies greatly a different foods. It is greatest to animal foods. There is great sensitivity to certain kinds of mucus.. 3. The active substances of natural foods are closely associated with protein. They fail to pass through a membrane which retains colloids. A feeding reaction can be obtained to food substances which appear to be insoluble in water.. 4. Though the active substances of many natural foods are not in free solution, soluble derivatives of ...
The effect of sea anemone toxins from Parasicyonis actinostoloides and Anemonia sulcata on the Na conductance in crayfish giant axons was studied under voltage-clamp conditions. The toxin slowed the Na inactivation process without changing the kinetics of Na activation or K activation in an early stage of the toxin effect. An analysis of the Na current profile during the toxin treatment suggested an all-or-none modification of individual Na channels. Toxin-modified Na channels were partially inactivated with a slower time course than that of the normal inactivation. This slow inactivation in steady state decreased in its extent as the membrane was depolarized to above -45 mV, so that practically no inactivation occurred at the membrane potentials as high as +50 mV. In addition to inhibition of the normal Na inactivation, prolonged toxin treatment induced an anomalous closing in a certain population of Na channels, indicated by very slow components of the Na tail current. The observed kinetic ...
Antho-KAamide (L-3-phenyllactyl-Phe-Lys-Ala-NH2) and Antho-RIamide (L-3-phenyllactyl-Tyr-ArgIle-NH2) are novel neuropeptides isolated from the sea anemone Anthopleura elegantissima. They both inhibited spontaneous contractions of isolated muscle preparations from a wide variety of anemone species (threshold around 10-7 m ). Their actions were universal in that they inhibited every muscle preparation tested, regardless of whether the muscle group was located in the ectoderm or endoderm, or was oriented in a circular or longitudinal direction. Injection of Antho-KAamide or Antho-RIamide into the coelenteron of intact sea anemones resulted in a marked expansion of the animals. Similar shape changes followed feeding or exposure to soluble food extracts. Therefore, we hypothesize that nerve cells that release Antho-KAamide and Antho-RIamide are involved in the expansion phase of feeding behaviour in sea anemones. ...
We purified a new cytolysin (HMgIII) from the sea anemone, Heteractis magnifica. HMgIII, which has a molecular mass of ~19 kDa, functions as both a cytolysin and a hemolysin. The full-length HMg III cDNA was obtained by reverse transcriptase-polymerase chain reaction, using primers designed from its N-terminal amino acid sequence and an internal conserved region of two other sea anemone cytolysins: equinatoxin II (EqT II) and cytolysin III. The cDNA contained an open reading frame of 633 bp, which encodes a protein of 211 amino acids. The nascent HMg III protein contained a prepropeptide of 34 amino acids, which includes a signal peptide of 19 amino acids. The mature HMg III has a predicted molecular mass of 19 kDa and a pI of 9.1, and shares 91%, 89%, 65% and 63% amino acid sequence similarity with cytolysin III, cytolysin ST I, tenebrosin-C and equinatoxin (EqT II), respectively. The predicted secondary structure of the mature HMg III comprises 16% α-helix, 23% extended strand and 60% random ...
Learn Sulcata tortoise appearance covers the different Sulcata tortoise colors available, ivory, Albino sulcata tortoise and other tortoise colors.
Title:Analgesic and CNS Depressant Activities of Sea Anemone Heteractis aurora Nematocyst Toxin. VOLUME: 16 ISSUE: 3. Author(s):Sengapillai Thangaraj, Subramanian Bragadeeswaran, Natarajah Srikumaran and Anbukkarasu Suguna. Affiliation:Marine Biotoxinology Lab. Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai - 608 502, Tamil Nadu, India.. Keywords:Analgesic activity, CNS depressant activity, Heteractis aurora, Haemolytic activity, Sea anemone.. Abstract:Marine organisms are the excellent sources for biologically active compounds. Cnidarian venoms are potentially valuable materials used for biomedical research and drug development. The present work was carried out to analyse haemolytic, analgesic and CNS depressant activity of sea anemone Heteractis aurora. In haemolytic assay, among the five different RBC blood cells, the chicken blood exhibited maximum hemolytic activity of 64 Hemolytic Unit (HU). The maximum Analgesic Ratio (AR) of 5 ...
It is well known that the activities of the lysosomal cysteine proteinases are tightly regulated by their endogenous inhibitors, cystatins. Here we report a new inhibitor of cysteine proteinases isolated from sea anemone Actinia equina. The inhibitor, equistatin, is an acidic protein with pI 4.7 and molecular weight of 14,129. It binds tightly and rapidly to cathepsin L (ka = 5.7 x 10(7) M-1 s-1, Ki = 0.051 nM) and papain (ka = 1.2 x 10(7) M-1 s-1, Ki = 0.57 nM). The lower affinity for cathepsin B (Ki = 1.4 nM) was shown to be due mainly to a lower second order association rate constant (ka = 0.04 x 10(6) M-1 s-1). The inhibitor is composed of 128 amino acids forming two repeated domains with 48% identity. Neither of the domains shows any sequence homology to cystatins, but they do show a significant homology to thyroglobulin type-1 domains. A highly conserved consensus sequence motif of Cys-Trp-Cys-Val together with conserved Cys, Pro, and Gly residues is present in major histocompatibility ...
1BDS: Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing.
1BDS: Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing.
Background: Gain-of-function mutations of the nociceptive voltage-gated sodium channel Nav1.7 lead to inherited pain syndromes, such as paroxysmal extreme pain disorder (PEPD). One characteristic of these mutations is slowed fast-inactivation kinetics, which may give rise to resurgent sodium currents. It is long known that toxins from Anemonia sulcata, such as ATX-II, slow fast inactivation and skin contact for example during diving leads to various symptoms such as pain and itch. Here, we investigated if ATX-II induces resurgent currents in sensory neurons of the dorsal root ganglion (DRGs) and how this may translate into human sensations. Results: In large A-fiber related DRGs ATX-II (5 nM) enhances persistent and resurgent sodium currents, but failed to do so in small C-fiber linked DRGs when investigated using the whole-cell patch-clamp technique. Resurgent currents are thought to depend on the presence of the sodium channel beta 4-subunit. Using RT-qPCR experiments, we show that small DRGs ...
Neurones of the motor nerve net of the jellyfish Cyanea capillata were axotomized, and voltage-clamped using the whole-cell configuration of the patch-clamp technique.. Outward currents were blocked by a combination of extracellular 4-aminopyridine (4-AP) and intracellular Cs+, tetraethylammonium (TEA+) and 4-AP.. Under normal conditions, the inward current consisted of a fast, transient current which could be abolished by removal of extracellular Na+ and whose reversal potential was dependent on the extracellular Na+ concentration.. This current was completely insensitive to tetrodotoxin (TTX), saxitoxin (STX) and conotoxin GIIIA but could be blocked by extracellular Cd2+, lidocaine, W7 [N-(6 aminohexyl)-5-chloro-1-napthalenesulphonamide] and verapamil.. Inactivation was voltage-dependent with a Vh of −15mV, and was unaffected by veratridine, batrachotoxin (BTX), sea anemone toxin and scorpion (Leiurus) venom. Reactivation required repolarization to a negative membrane potential for 12 ms for ...
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The lethal marine toxin, palytoxin, first extracted from the polyps of soft-bodied zoanthids of the genus Palythoa (Moore and Scheuer, 1971), is a potentially useful tool for elucidating the molecular reactions by which the Na/K-ATPase stoichiometrically transports Na+ and K+ ions in opposite directions across the cell surface membrane. Palytoxin was found to depolarize mammalian cells (e.g., Weidmann, 1977) by causing small-conductance (∼10 pS) relatively nonselective cation channels to appear in their surface membranes (e.g., Ikeda et al., 1988; Muramatsu et al., 1988). That the Na/K-ATPase is the target for palytoxin action was initially surmised (Habermann, 1989) largely from antagonism of toxin action by cardiotonic steroids, like ouabain, or by K+ ions. Two experimental approaches have since confirmed that proposal. The first exploited the absence of endogenous Na/K pumps from yeast and showed that palytoxin could elicit ouabain-sensitive cation flux in yeast expressing both α and β ...
Bunodosine 391 (BDS 391), a low molecular weight compound isolated from the sea anemone Bunodosoma cangicum, increases the nociceptive threshold and inhibits inflammatory hyperalgesia. Serotonin receptors are involved in those effects. In this study, we have expanded the characterization of the antinociceptive effect of BDS 391 demonstrating that, in rats: (a) the compound inhibits (1.2-12 ng/paw) overt pain, in the formalin test, and mechanical hyperalgesia (0.6-6.0 ng/paw) detected in a model of neuropathic pain; (b) intraplantar administration of ondansetron, a selective 5-HT3 receptor antagonist, blocks the effect of BDS 391, whereas ketanserin, a 5-HT2 receptor antagonist, partially reversed this effect, indicating the involvement of peripheral 5-HT2 and 5-HT3 receptors in BDS 391 antinociception; and (c) in binding assay studies, BDS 391 was not able to displace the selective 5-HT receptor antagonists, suggesting that this compound does not directly bind to these receptors ...
Two cytolysins, designated as magnificalysins I and II, were purified from a tropical sea anemone, Heteractis magnifica (formerly Radianthus ritteri). The purification steps involved Sephadex G-50 and CM-Sepharose chromatography followed by Mono S and Phenyl-Superose Fast Protein Liquid Chromatography. The relative mol. wt of magnificalysins I and II, determined by SDS-PAGE, was approximately 19,000, while their isoelectric points, determined by isoelectric focusing in immobilized pH gradients, were 9.4 and 10.0, respectively. Those toxins were found to have haemolytic and lethal activities. The haemolytic activities of magnificalysins I and II were 3.6 x 104 HU/mg and 3.3 x 104 HU/mg, while their LD50 (i.v., mice) values were approximately 0.14 μg/g and 0.32 μg/g, respectively. The amino acid composition and N-terminal sequences of magnificalysins I and II were also obtained. They do not possess any cysteine or cystine residue, but are rich in basic and hydrophobic amino acids. The N-terminal ...
New study reveals that a synthetic compound ShK-186, which comes from a sea anemone toxin can be used to treat obesity and insulin resistance.
Sulcatas come from some of the Sahel, the hottest, driest area in Africa. Some regions may not get rain for years. To make the most of available moisture, their skin is resistant to fluid loss but, when exposed to moisture, may become highly permeable. Towards this end, they will excavate pallets or burrows in the ground to get to areas with higher moisture levels; in the wild, they may spend the hottest part of the day in these microhabitats. Burrows may average 30 inches in depth; some dig tunnel systems extending 10 feet or more underground. Sulcatas are, like most turtles and tortoises native to dry areas, extremely efficient in their use of water. A sulcata may urinate just 0.64 ml a day, significantly less than their spur-thighed cousins living in the relatively lush Mediterranean countries who may urinate 1-2 ml a day. A danger, then, in captivity is that too much water may be given or made accessible which may lead to health problems including skin and shell infections and kidney problems ...
Sulcatas come from some of the Sahel, the hottest, driest area in Africa. Some regions may not get rain for years. To make the most of available moisture, their skin is resistant to fluid loss but, when exposed to moisture, may become highly permeable. Towards this end, they will excavate pallets or burrows in the ground to get to areas with higher moisture levels; in the wild, they may spend the hottest part of the day in these microhabitats. Burrows may average 30 inches in depth; some dig tunnel systems extending 10 feet or more underground. Sulcatas are, like most turtles and tortoises native to dry areas, extremely efficient in their use of water. A sulcata may urinate just 0.64 ml a day, significantly less than their spur-thighed cousins living in the relatively lush Mediterranean countries who may urinate 1-2 ml a day. A danger, then, in captivity is that too much water may be given or made accessible which may lead to health problems including skin and shell infections and kidney problems ...
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Looking for Noctiluca? Find out information about Noctiluca. a genus of protozoa of the class Mastigophora of the order Dinoflagellata. The spherical body is 2 to 3 mm in diameter and has a mobile, contractive... Explanation of Noctiluca
Release of aqueous contents from model lipid vesicles has been a standard procedure to evaluate pore formation efficiency by actinoporins, such as sticholysin II (StnII), for the last few decades. However, regardless of the probe of choice, the results reported that StnII action was never able to empty the vesicles completely. This was hard to explain if StnII pores were to be stable and always leaky for the probes used. To address this question, we have used a variety of probes, including rhodamine 6G or Tb3+, to test the permeability of StnIIs pores... ...
When the sea anemone is in the larval stage it swims. As adults, the sea anemone stands with one end on the sea floor and uses long tentacles on its upper end to catch small animals which they stuff into the only body opening in the middle of the ring of tentacles.. Based on the appearance of the adult animals, the lower end of these animals has traditionally been called the foot and the upper end the head, explains Rentzsch.. What the research group found out was that in the sea anemone the head gene function is located at the end that corresponds to the foot of the adult animals. The key was to study the larvae of the sea anemones when they still move around.. The larvae swims with the foot end forward and this end carries their main sense organ, so at this stage it looks more like this might be their head, says Rentzsch. And indeed, the head genes function on this side of the animals.. Sea anemones and all higher animals, including humans, share a common brainless ancestor which ...
Pore-forming protein that forms cations-selective hydrophilic pores of around 1 nm and causes cytolysis. Pore formation is a multi-step process that involves specific recognition of membrane sphingomyelin (but neither cholesterol nor phosphatidylcholine) using aromatic rich region and adjacent phosphocholine (POC) binding site, firm binding to the membrane (mainly driven by hydrophobic interactions) accompanied by the transfer of the N-terminal region to the lipid-water interface and finally pore formation after oligomerization of monomers.
The results completely change the way we think of the origin of germ layers. It means that endoderm in sea anemones and vertebrates, although they are called the same, are actually not evolutionary related adds Ulrich Technau. If the mouth ectoderm of the sea anemone and not the endoderm corresponds to the vertebrate gut and pancreas, then what is the vertebrate correlate of the sea anemone endoderm? When Steinmetz and Technau dwelled deeper into this question, they found strong similarities between the cnidarian endoderm and the intermediate mesoderm layer: both share a large number of regulatory genes, and both give rise to similar cell types such as muscle or gonad cells. The sea anemone thus shows a clear correlate of mesoderm, but not in an intermediate position as found in three-layered animals. Positioning, and not novel emergence, of tissue in-between the gut and skin was thus the key event that led to the evolution of three-layered animals. An overwhelming majority of animals ...
Reuben went over how to properly design a scientific experiment and the statistics involved with analyzing the results. Afterwards each group met with Sally, Sarah, Su, Liz, and Reuben to pitch their project idea. Our project (Rachel, Kenzie, and Jake) is studying the effects of temperature and feeding on the regeneration and survival of Anthopleura elegantissima. They liked our ideas but some of the logistics had to be changed. This is an important aspect of learning about the scientific process. It often takes lots of thinking and rethinking about the project design to come to a final workable design. Theres always a trade-off between the best design and whats actually feasible with the resources and time available. Friday evening was also the due date for our project proposals, which included an introduction on the topic, materials and methods, expected results and significance. Proposals are an important part of the process of conducting a scientific experience. If you need funding you ...
Reuben went over how to properly design a scientific experiment and the statistics involved with analyzing the results. Afterwards each group met with Sally, Sarah, Su, Liz, and Reuben to pitch their project idea. Our project (Rachel, Kenzie, and Jake) is studying the effects of temperature and feeding on the regeneration and survival of Anthopleura elegantissima. They liked our ideas but some of the logistics had to be changed. This is an important aspect of learning about the scientific process. It often takes lots of thinking and rethinking about the project design to come to a final workable design. Theres always a trade-off between the best design and whats actually feasible with the resources and time available. Friday evening was also the due date for our project proposals, which included an introduction on the topic, materials and methods, expected results and significance. Proposals are an important part of the process of conducting a scientific experience. If you need funding you ...
basis of record van der Land, J.; den Hartog, J.H. (2001). Actiniaria, ,B,,I,in,/I,,/B,: Costello, M.J. ,i,et al.,/i, (Ed.) (2001). ,i,European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels,,/i, 50: pp. 106-109 (look up in IMIS) [details] ...
The second goal? Simply to document whats down there, says Adkins.. In one sense, the deep ocean is less explored than Mars, he adds. So every time you go to look down there you see new things, magical things.. Among the magical things seen on this trip were - a new species of carnivorous sea squirt that looks and behaves like a Venus fly trap, says Adkins; - new species of barnacles (some of which Adkins says may even belong to an entirely new family); and - a new species of sea anemone that Adkins calls the bane of our existence, because it looks just like the coral they were trying to collect.. The sea anemone was particularly vexing for the researchers, because they were hoping to find deep-sea (or abyssal) samples of the fossilized coral, but were unable to find the coral much below 2,400 meters (nearly 7,800 feet). The look-alike sea anemone, on the other hand, kept popping up all over the place on the deep-sea floor, raising--and then dashing--the scientists hopes.. Not ...
Mouse neuroblastoma N-18 cells, which evoked a mixed Na+ and Ca2+ action potential under appropriate tissue culture conditions, were used to study the electrophysiological pharmacology of a polypeptide neurotoxin (ATX-II) from a sea anemone. When applied extracellularly, ATX-II in concentrations as low as 10-7 M increased reversibly the electrical excitability of N-18 cells, e.g., the toxin caused spontaneous firing in which the duration and the maximal rate of rise of each action potential were increased. A set of results obtained in this work strongly suggests that this effect of the toxin was mainly due to its interaction with the inactivation gate of the Na+ channel of N-18 cells, i.e., ATX-II inhibited both the time-dependent and the steady-state processes of Na+ channel inactivation. Accordingly, this toxin is a useful tool for elucidating the molecular structure of the voltage-sensitive inactivation gate of the Na+ channel.. ...
About ten years ago while working in a hospital i saw the most horrific sight . A group of girls, i think college age, all from Brazil, had come here and i guess didnt know much about box jellies or stinger suits. All 7 of them were swimming in irukandji infested waters in just their bikinis and all 7 of them got stung multiple times. ive never seen such suffering. when i first saw them, they were laying on the floor of the emergency room waiting area where they had collapsed after being brought in. the screaming and moaning filled the halls and you could hear them from the second floor. There were lying there, on the floor piled around each other, writhing in pain, still in their swimsuits and soaked with sweat. I remember at least three of the girls were violently bucking, thrashing and kicking their legs around like they were being drowned in acid. i remember being unsettled by how the girls legs and bodies writhed around against each other and yet they were completely oblivious of their ...
This page is a collection of people that are attached to a branch of the Tree of Life.. For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.. close box ...
Cloning of GFP - posted in Molecular Cloning: Hi there, So I recently ligated my gene into a Pet32a vector using restriction sites using EcoR1 and Xho1. From another Pet vector I have to create primers for the GFP insert containing BgII and EcoR1 sites. Just wondering, once I amplify my GFP (using BgII/EcoR1 sites), how do I ligate it into my original construct..Do I cut my original constuct with EcoR1 and BgII (because looking at the vector map, Pet32a has a BgII site and ligate?) Che...
The host plant spectre of a parasite is rarely known exhaustively; this applies in particular at the species level. It is advisable therefore to check at least also the list of all parasites of this genus ...
Define Edwardsia: a genus (the type of the family Edwardsiidae) of sea anemones having eight mesenteries and living in tubes in the sand
Title:Crude Venom from Nematocysts of the Jellyfish Pelagia noctiluca as a Tool to Study Cell Physiology. VOLUME: 15 ISSUE: 2. Author(s):Rossana Morabito, Giuseppina L. Spada, Rosalia Crupi, Emanuela Esposito and Angela Marino. Affiliation:Department of Biological and Environmental Sciences, Viale F. Stagno DAlcontres 31, 98166 Messina, Italy.. Keywords:Biological assays, crude venom, jellyfish, nematocysts, Pelagia noctiluca.. Abstract:Marine animals represent a source of novel bioactive compounds considered as a good research model, whose mechanism of action is intriguing and still under debate. Among stinging animals, Cnidarians differentiated highly specialized cells, termed nematocytes, containing a capsule fluid with toxins and an inverted tubule, synergistically responsible for mechanisms of defence and predation. Such compounds include proteins and secondary metabolites with toxic action. With the aim of better elucidating the effects of Cnidarian venom upon cell targets, this short ...
Relatively few studies have investigated the genetic population structure of sea anemones. This is particularly true for sea anemones that host some of the most iconic fishes on coral reefs, the anemonefishes. One of the main reasons for this knowledge gap is the lack of appropriate genetic markers. We developed and characterized a total of 47 novel polymorphic microsatellite markers for four host sea anemone species from the Indo-Pacific: Entacmaea quadricolor (n = 16 microsatellite markers), Heteractis magnifica (n = 8), Stichodactyla mertensii (n = 13), and Stichodactyla gigantea (n = 10). Here, we report genetic diversity statistics from two different sampling locations for each anemone species. Overall, we found that most markers were highly polymorphic. On average, we found a mean of seven alleles per locus. Observed and expected heterozygosities displayed high variation among loci, ranging from 0.033 to 0.980 and from 0.038 to 0.927, respectively. Only four loci showed deviations of ...
Luminescent Jellyfish, Pelagia Noctiluca, France, Mediterranean Sea Photographic Print by Reinhard Dirscherl. Find art you love and shop high-quality art prints, photographs, framed artworks and posters at Art.com. 100% satisfaction guaranteed.
The dinoflagellate Noctiluca scintillans (Noctiluca) has the ability to reproduce sexually, which may help to increase or restore its population size during periods of blooms or environmental stress. Here, we documented for the first time a marine ciliate Strombidium sp. that feeds on Noctilucas progametes undergoing stages 5 to 9 of nuclear division. This ciliate frequently swam on or around gametogenic and some vegetative Noctiluca cells. The ciliates associated with gametogenic cells had significantly lower swimming speed and changed direction more frequently than those associated with vegetative cells, which overall increased their time spent around the food patches (progametes). This trophic interaction constitutes an upside-down predator -prey link, in which ciliates within the typical size range of Noctiluca prey, become the predators. Based on the phylogenetic tree (maximum-likelihood), there are 14 environmental clones similar to Strombidium sp. found in other coastal waters, where ...
A pale yellow-colored, moderately halophilic, Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped, motile, aerobic bacterium, designated strain JSM 073008T, was isolated from a sea anemone (Anthopleura xanthogrammica) collected from Naozhou Island, Leizhou Bay, South China Sea. The organism was able to grow with 1-20% (w/v) total salts (optimum, 5-10%), at pH 6.0-10.0 (optim ...
Healthy thalli of Parmelia sulcata Taylor were transplanted to 8 localities in the surroundings of a power station (La Robla, Leon, Spain), the sole pollution source in the region. Changes in chlorophyll a fluorescence were monitored in the transplants 12 months, 18 months and 24 months after transplantation. Statistically significant differences were observed in the ratio of variable to maximal fluorescence, non-photochemical fluorescence quenching and vitality index. The decrease in fluorescence parameters was higher in the localities of Cuadros and Rabanal de Fenar, which are situated a few kilometres away from the power station and in the same direction as the prevailing winds ...
Looking for online definition of palytoxin in the Medical Dictionary? palytoxin explanation free. What is palytoxin? Meaning of palytoxin medical term. What does palytoxin mean?
Bell and trailing tentacles of a box jellyfish (Cubozoa). Box jellyfish are relatives of true jellyfish, but have a cubic bell and tentacles extending from each lower corner. Unlike true jellyfish they have complex eyes and are active swimmers, avoiding obstacles and chasing after prey. They feed mainly on small fish, which they catch with their stinging tentacles. Some species of box jellyfish have a sting that is rapidly fatal to humans. Filmed in the Gulf of Thailand, near Koh Pha Ngan Island. - Stock Video Clip K004/8614
The jellyfish venom essence creamgel is concentrated in natural ingredients from the sea such as fibrilin. It is a very effective anti-age natural.
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|div|The Saddle Anemone, |i|Stichodactyla haddoni|/i|, is commonly referred to as Haddons Anemone, Saddle Carpet Anemone, or the Saddleback Anemone. It features short and blunt stinging tent
Sodium channels expressed in cardiac muscle cells are resistant to nanomolar concentrations of TTX, and require micromolar concentrations for inhibition. On the other hand, these channels are more sensitive to inhibition by lidocaine than are CNS channels.. The receptor sites for these toxins are formed by amino acid residues in the pore loops and immediately on the extracellular side of the pore loops at the outer end of the pore. Neurotoxin receptor site 2 binds a family of lipid-soluble toxins, including batrachotoxin, veratridine, aconitine, and grayanotoxin, which enhance activation of sodium channels. Photoaffinity labeling and mutagenesis studies implicate transmembrane segments IS6 and IVS6 in the receptor site for batrachotoxin [815]. Neurotoxin receptor site 3 binds the alpha-scorpion toxins and sea anemone toxins, which slow the coupling of sodium channel activation to inactivation. These peptide toxins bind to a complex receptor site that includes the S3-S4 loop at the outer end of ...
You searched for: Contributor McPeak, Ronald H. Remove constraint Contributor: McPeak, Ronald H. Genre slides (photographs) Remove constraint Genre: slides (photographs) Topic Sea anemones Remove constraint Topic: Sea anemones Place Santa Rosa Island (Calif.) Remove constraint Place: Santa Rosa Island (Calif.) Format Still Image Remove constraint Format: Still Image ...
Portier and Richet first coined the term anaphylaxis in 1902 when a second vaccinating dose of sea anemone toxin caused a dogs death. The term is derived from the Greek words ana - (
Portier and Richet first coined the term anaphylaxis in 1902 when a second vaccinating dose of sea anemone toxin caused a dogs death. The term is derived from the Greek words ana - (
Intracellular Ca2+ overload induced by extracellular Ca2+ entry has previously been confirmed to be an important mechanism for the cardiotoxicity as well as the acute heart dysfunction induced by jellyfish venom, while the underlying mechanism remains to be elucidated. Under extracellular Ca2+-free or Ca2+-containing conditions, the Ca2+ fluorescence in isolated adult mouse cardiomyocytes pre-incubated with tentacle extract (TE) from the jellyfish Cyanea capillata and β blockers was scanned by laser scanning confocal microscope. Then, the cyclic adenosine monophosphate (cAMP) concentration and protein kinase A (PKA) activity in primary neonatal rat ventricular cardiomyocytes were determined by ELISA assay. Furthermore, the effect of propranolol against the cardiotoxicity of TE was evaluated in Langendorff-perfused rat hearts and intact rats. The increase of intracellular Ca2+ fluorescence signal by TE was significantly attenuated and delayed when the extracellular Ca2+ was removed. The β adrenergic
This course seeks to give the participant the necessary tools to start and/or continue studies on the taxonomy and diversity of sea anemones in a broad sense, i.e. including the order Actiniaria (sea anemones sensu stricto), Corallimorpharia (mushroom anemones) and Zoanthidea (matt anemones). The course will last twelve days, with five days dedicated to taxonomic training, including the characteristics and identification of the various actiniarian suborders, superfamilies and families; the orders Corallimorpharia and Zoanthidea will be also considered. Three days will be dedicated to learning colleting, fixation and preservation methods, histological techniques necessary for sea anemone identification as well as cnidae preparation and identification. Common taxa at Bocas del Toro will be identified to species. We will conduct surveys of sea anemones at several field sites near the Bocas Research Station to collect baseline data for conservation and for future studies. The remaining three days ...
Stinging cells can be used as tiny needles to inject drugs into the skin - sea anemone face creams should be available to buy next year
Box jellyfish stings are excruciating and occasionally deadly. Scientists have now identified a common, cheap drug that is already on the market and which could be a treatment candidate with further
Dear Friends & Neighbors, (Please click on red links & note magenta) Weve driven past the Tibet-Butler Preserve on C.R. 535 on Winter Garden-Vineland Road multiple times, but it wasnt until our daughter visited.... ...
TY - JOUR. T1 - An examination of the cardiovascular effects of an Irukandji jellyfish, Alatina nr mordens. AU - Winter, Kelly. AU - Isbister, Geoffrey. AU - Schneider, Jennifer. AU - Konstantakopoulos, Nicki. AU - SEYMOUR, J. AU - Hodgson, Wayne. PY - 2008. Y1 - 2008. N2 - Irukandji syndrome is usually characterized by delayed severe abdominal, back and chest pain associated with autonomic effects including diaphoresis, hypertension and, in severe cases, myocardial injury and pulmonary oedema. It is most often associated with envenoming by the jellyfish Carukia barnesi, but a number of other jellyfish, including Alatina mordens, are now known to produce Irukandji syndrome. In the present study, nematocyst-derived venom from A. nr mordens (150-250 ?g/kg, i.v.) produced a long-lasting pressor effect in anaesthetised rats. This pressor response (250 ?g/kg, i.v.) was significantly inhibited by prior administration of the ?-adrenoceptor antagonist prazosin (200 ?g/kg, i.v.) but not by CSL box ...
A sea creature sting can usually be treated with first aid. But if serious symptoms develop, such as severe pain, swelling or difficulty breathing, dial 999 for an ambulance.
Cruise summary report for RV Pelagia PE319 (GA02 Leg1) - produced from a first level inventory of measurements and samples collected at sea that provides information on who has collected what, where and when. Assembled initially from cruise plans and then updated from other sources including the Intergovernmental Oceanographic Commission (IOC) Cruise Summary Report (ROSCOP) forms submitted to BODC for each UK research cruise. Provides a useful resource of cruise activities to scientists, programme managers and data managers.
Beaded sea anemone, green, Reef Frontiers is dedicated to bring the best information to marine reef aquarium hobbyists , with friendly forums filled with experienced reef keepers to libraries, webinars, galleries and much more. Come join us
TY - JOUR. T1 - Pore-forming proteins and adaptation of living organisms to environmental conditions. AU - Andreeva-Kovalevskaya, Zh I.. AU - Solonin, A. S.. AU - Sineva, E. V.. AU - Ternovsky, V. I.. PY - 2008/12/1. Y1 - 2008/12/1. N2 - Pore-forming proteins are powerful tools for adaptation of living organisms to environmental conditions. A wide range of these proteins isolated from various sources, from viruses to mammals, has been used for the analysis of their role in the processes of intra- and inter-species competition, defense, attack, and signaling. Here we review a large number of pore-forming proteins from the perspective of their functions, structures, and mechanisms of membrane penetration. Various mechanisms of cell damage, executed by these proteins in the course of formation of a pore and after its passing to conducting state, have been considered: endo- and exocytosis, lysis, necrosis, apoptosis, etc. The role of pore-forming proteins in evolution is discussed. The relevance ...
Experience the beauty and diversity of South African National Parks, Travel and explore South Africa! Nature Conservation, Accommodation, Activities, Reservations
Experience the beauty and diversity of South African National Parks, Travel and explore South Africa! Nature Conservation, Accommodation, Activities, Reservations
Hi Matt,. Thanks for the comment and question. Just from my personal experience I have been treating all my anemones ever since I started doing this treatment a few months ago. I am currently on day 4 of my next LTA. I have also been able to save a Lime BTA a month ago since I got lazy and figured it looked healthy enough with a tight mouth at the store but seemed to have started rotting on one edge and losing tentacles after having it for a week. What appeared healthy at the store can still have a hard time transitioning into your system and thats when I think they are susceptible the most.. Like quarantining fish and dipping corals I have learned the hard way that if I could prevent it I should do it. Its always the one time I dont do it that something bad happens. I would say if you do treat the anemone it would have a more than just a 50/50 shot chance of survival.. As far as splits from fellow reefers I think those are still hardier, just like LPS/SPS frags, tend to be hardier since they ...
Brighten up your borders with an adorable Anemone thats easy to grow, early-blooming, and full of sensational color! Bare Root Plants For Sale Now!
In Governing for the Long Term, Alan M. Health download sleeping with anemone verges Canada sad sure commercial frequency and for national usage. totally-inappropriate self-organization gives new list. Stephen Curry: My advantageous to Success.
Hassler, M. 2018. Anemone. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2018. Species 2000 & ITIS Catalogue of Life. Published on the internet. Accessed: 2018 Oct. 11. Reference page ...
Painted by Natasha Wescoat, Blue Anemone wall mural from Murals Your Way will add a distinctive touch to any room. Choose a pre-set size, or customize to your wall.
At 9 days old, uZair is able to turn by himself. I placed him on his tummy in his cot. Few minutes later I came in the room and he was no longer on his tummy ...
I absolutely agree with this. I am determined for people not to see me with granny goggles. Its shocking how early it starts, too. Thats why I detest the whole identifying women as over 40 thing. As if once over 40 youre part of this huge, undifferentiated mass of old chicks. Like 20, 30, OLD. LOL. Not that there is anything whatever the matter with being older. Its just that identifying women who are middle aged and older as over 40 strikes me as oddly dehumanizing. Ive also noticed with age how everyone is so hung up on age. To hear the 28 year olds going on about how they have two years before theyre old is just silly. Everyone always needs to know how old you are, as well. I dont like mentioning my age, personally. It always elicits gasps and parlor guessing games. I imagine this type of behavior is uniquely American as well. By the way Im 46, and I look 15 years younger, if what people say is any indication. I am told I should be proud of my age. Why? For continuing to beat fate ...
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... wasp venoms MeSH D23.946.833.230 - cnidarian venoms MeSH D23.946.833.370 - fish venoms MeSH D23.946.833.590 - mollusk venoms ... cnidarian venoms MeSH D23.946.580.370 - fish venoms MeSH D23.946.580.450 - holothurin MeSH D23.946.580.565 - lyngbya toxins ... arthropod venoms MeSH D23.946.833.065.055 - ant venoms MeSH D23.946.833.065.115 - bee venoms MeSH D23.946.833.065.115.060 - ... viper venoms MeSH D23.946.833.850.960.200 - crotalid venoms MeSH D23.946.833.850.960.200.050 - ancrod MeSH D23.946.833.850. ...
After many tests on frogs, it was determined that A. aurita has a proteinaceous venom that causes muscle twitching by inducing ... "Preliminary Results of the in Vivo and in Vitro Characterization of a Tentacle Venom Fraction from the Jellyfish Aurelia aurita ...
Cnidarian Toxins and Venoms. 54 (8): 1071-1074. doi:10.1016/j.toxicon.2009.02.027. ISSN 0041-0101. PMID 19268681. da Silva, ... Venom is a type of poison, especially one secreted by an animal. Venom has evolved in a wide variety of animals, both predators ... Snake venom may have originated with duplication of genes that had been expressed in the salivary glands of ancestors. Venom is ... Venoms cause their biological effects via the toxins that they contain; some venoms are complex mixtures of toxins of differing ...
UHMedNow, "Angel Yanagihara's box jellyfish venom research leads to sting treatment", March 4, 2011 PBS Nova, Venom: Nature's ... Box jellyfish (class Cubozoa) are cnidarian invertebrates distinguished by their cube-shaped medusae. Some species of box ... the venom contained in their tentacles. Its effectiveness was demonstrated in the PBS Nova episode "Venom: Nature's Killer", ... "Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote". Nature Communications. 10 (1 ...
Pelagic cnidarians (jellyfish and related species) have nematocysts on their tentacles that eject a coiled microscopic thread ... These threads penetrate the surface of their target and release a series of complicated, biologically advanced venoms. Their ...
Venom from animals such as cnidarians, scorpions and spiders may be species-specific. A substance that is weakly toxic for ... Other cnidarians, such as the jellyfish Cyanea capillata (the "Lion's Mane" made famous by Sherlock Holmes) or the siphonophore ... This prevents the cnidarian from stinging itself although sloughed off cnidae can be induced to fire independently. ... Over 30 types of cnidae are found in different cnidarians. They can be divided into the following groups: *Penetrant: The ...
Prey of cnidarians ranges from plankton to animals several times larger than themselves.[34][37] Some cnidarians are parasites ... Nematocysts inject venom into prey, and usually have barbs to keep them embedded in the victims. Most species have nematocysts. ... Recent phylogenetic analyses support monophyly of cnidarians, as well as the position of cnidarians as the sister group of ... The position of Anthozoa nearest the beginning of the cnidarian family tree also implies that Anthozoa are the cnidarians most ...
... wasp venoms MeSH D20.888.230 - cnidarian venoms MeSH D20.888.370 - fish venoms MeSH D20.888.590 - mollusk venoms MeSH D20.888. ... arthropod venoms MeSH D20.888.065.055 - ant venoms MeSH D20.888.065.115 - bee venoms MeSH D20.888.065.115.060 - apamin MeSH ... viper venoms MeSH D20.888.850.960.200 - crotalid venoms MeSH D20.888.850.960.200.050 - ancrod MeSH D20.888.850.960.200.105 - ... snake venoms MeSH D20.888.850.325 - elapid venoms MeSH D20.888.850.325.139 - bungarotoxins MeSH D20.888.850.325.220 - cobra ...
Cnidarians, such as jellyfish, sea anemones, Hydra and coral have numerous hair-like tentacles. Cnidarians have huge numbers of ... The longer tentacles are equipped with cnidocytes whose venom paralyses and kills prey. The smaller tentacles guide food into ... Bird J (5 June 2007). "CNIDARIANS: SIMPLE ANIMALS WITH A STING!". oceanicresearch.org. Oceanic Research Group. Archived from ...
Like many cnidarians, they rely on nematocysts for protection and to capture prey. They are not difficult to care for, and can ... The nematocyte venom of A. mutabilis contains at least one or more toxins with powerful cytolytic activity. However, conditions ... Like most nematocysts found in cnidarians, the nematocysts of A. mutabilis injects a tubule of venomous substances as a respose ... Marino, A.; Morabito, R.; La Spada, G. (March 2009). "Factors altering the haemolytic power of crude venom from Aiptasia ...
Cnidarians and ctenophoresEdit. Cnidarians, such as jellyfish, sea anemones, Hydra and coral have numerous hair-like tentacles ... The longer tentacles are equipped with cnidocytes whose venom paralyses and kills prey. The smaller tentacles guide food into ... Cnidarians have huge numbers of cnidocytes on their tentacles. In medusoid form, the body floats on water so that the tentacles ... "CNIDARIANS: SIMPLE ANIMALS WITH A STING!". oceanicresearch.org. Oceanic Research Group. Archived from the original on 7 July ...
"Therapeutic Value Of Peptides From Animal Venoms". Comprehensive Natural Products II, 2010, pp. 287-303.. .William R. Kem, ... "Coelenteron , Cnidarian Anatomy". Encyclopedia Britannica, 2020, https://www.britannica.com/science/coelenteron ."Stichodactyla ... 2017). Peptide therapeutics from venom: Current status and potential. Bioorganic & Medicinal Chemistry. 26. 10.1016/j.bmc. ...
This structure is believed to carry most of the venom within the entire nematocyst. The umbrella-shaped fleshy body of C. ... Burke, William (2002). "Cnidarians and human skin". Dermatologic Therapy. 15: 18-25. doi:10.1046/j.1529-8019.2002.01508.x. ... Chiropsoides buitendijki has potent venom that can harm human skin. Several reported cases of human injury have been reported ...
The proteins closest in structure to the macins are a superfamily of proteins derived from scorpion venom, dubbed the scorpion ... Hydramacin-1 was first isolated from epithelial cells of the cnidarian Hydra, a small (almost-microscopic) freshwater animal ...
Being cnidarians, they do possess distinctive harpoon-like injection stinging cells, and like many scyphozoans their ... Research also shows that pouring saltwater into stings significantly increases flow of venom into body. Browne, J., 2011, ...
... and throes were observed following venom injection. S. cyanea venom also contains some antibacterial activity. Human accidents ... "A report of 49 cases of cnidarian envenoming from southeastern Brazilian coastal waters". Toxicon. 40 (10): 1445-1450. ... The venom of Conus is a conotoxin, whose action occurs by blocking muscle and neural receptors. Two cases were recorded by ... Phoneutria nigriventer venom contains two fractions PhTx-1 and PhTx-2 which are potent for primates, however, the spider has ...
Examples include the crotamine toxin in snake venom, many scorpion toxins, some sea anemone toxins, and one of the toxins in ... "Evolution of cnidarian trans-defensins: Sequence, structure and exploration of chemical space". Proteins. 87 (7): 551-560. doi: ... There appear to have been multiple evolutionary recruitments of defensins to be toxin proteins used in the venoms of animals. ... June 2008). "Defensins and the convergent evolution of platypus and reptile venom genes". Genome Research. 18 (6): 986-94. doi: ...
In some slow-moving radially symmetrical marine animals such as ctenophores and cnidarians (including sea anemones and ... They have mouthparts called chelicerae which are often connected to venom glands as most spiders are venomous. They have a ... the gelatinous cuticle of cnidarians (polyps, sea anemones, jellyfish) and the collagenous cuticle of annelids. The outer ...
Although they lack a true brain, cnidarian jellyfish have a "ring" nervous system that plays a significant role in motor and ... Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom, but only some ... The subphylum Medusozoa includes all cnidarians with a medusa stage in their life cycle. The basic cycle is egg, planula larva ... Purcell, J.; Arai, M. (2001). Purcell, J. E; Graham, W. M; Dumont, H. J (eds.). "Interactions of pelagic cnidarians and ...
Examples include the crotamine toxin in snake venom,[30] many scorpion toxins,[31] some sea anemone toxins,[10] and one of the ... Mitchell ML, Shafee T, Papenfuss AT, Norton RS (July 2019). "Evolution of cnidarian trans-defensins: Sequence, structure and ... There appear to have been multiple evolutionary recruitments of defensins to be toxin proteins used in the venoms of animals.[ ... "Defensins and the convergent evolution of platypus and reptile venom genes". Genome Research. 18 (6): 986-94. doi:10.1101/gr. ...
Like cnidarians (jellyfish, etc.) and ctenophores (comb jellies), and unlike all other known metazoans, sponges' bodies are ... there is no evidence that they use venom.[11] ...
The venom is destroyed when it is cooked, and stargazers are sold in some fish markets with their electric organ removed. They ... Plants such as seaweeds, cnidarians such as sea anemones, arthropods like barnacles, and molluscs such as the common limpet and ... Grady, Denise Venom Runs Thick in Fish Families, Researchers Learn The New York Times 22 August 2006. Froese, Rainer and Pauly ...
Like cnidarians (jellyfish, etc.) and ctenophores (comb jellies), and unlike all other known metazoans, sponges' bodies consist ... there is no evidence that they use venom.[37] ... Cnidarians and ctenophores[23]. Nervous system. No. Yes, simple ... cnidarians and bilaterians). Since choanoflagellates are thought to be animals' closest single-celled relatives, a team of ... cnidarians; algae; foraminiferans; a completely separate phylum of animals, Archaeocyatha; or even a completely separate ...
"Australian Venom Research Unit. Retrieved 2008-10-03.. *^ a b Williamson, J.A.; Fenner, P.J.; Burnett, J.W.; Rifkin, J. (1996 ... Their venom is a complex mixture of toxins, some fast-acting and others slower but deadlier.[100][96][101] The effects of ... Some molluscs sting or bite, but deaths from mollusc venoms total less than 10% of those from jellyfish stings.[96] ... but their venom kills 25% of human victims. Another tropical species, Octopus apollyon, causes severe inflammation that can ...
Venom[edit]. Further information: Venom and Evolution of snake venom. Many smaller predators such as the box jellyfish use ... most cnidarians (e.g., jellyfish, hydroids), ctenophora (comb jellies), echinoderms (e.g., sea stars, sea urchins, sand dollars ... venom to subdue their prey,[86] and venom can also aid in digestion (as is the case for rattlesnakes and some spiders).[87][88] ... However, when the prey is capable of killing the predator (as can a coral snake with its venom), there is no opportunity for ...
Cnidarians can be compared to Ctenophores (comb jellyfish), which although are both jellyfish, have very different nervous ... Unlike Cnidarians, Ctenophores have neurons that use electrochemical signaling. This was perplexing because the phylum ... The other theory states that the nervous system arose independently twice, one basal to Cnidarians and one basal to Ctenophores ... Snake venom. Tempo and modes. *Gradualism/Punctuated equilibrium/Saltationism. *Micromutation/Macromutation. *Uniformitarianism ...
VenomEdit. Further information: Venom and Evolution of snake venom. Many smaller predators such as the box jellyfish use venom ... most cnidarians (e.g., jellyfish, hydroids), ctenophora (comb jellies), echinoderms (e.g., sea stars, sea urchins, sand dollars ... However, when the prey is capable of killing the predator (as can a coral snake with its venom), there is no opportunity for ... A more symmetric arms race may occur when the prey are dangerous, having spines, quills, toxins or venom that can harm the ...
... are probably extremely reduced cnidarians).[17] ... Snake venom. Tempo and modes. *Gradualism/Punctuated ...
Prey of cnidarians ranges from plankton to animals several times larger than themselves.[37][40] Some cnidarians are parasites ... Nematocysts inject venom into prey, and usually have barbs to keep them embedded in the victims. Most species have nematocysts. ... Recent phylogenetic analyses support monophyly of cnidarians, as well as the position of cnidarians as the sister group of ... The position of Anthozoa nearest the beginning of the cnidarian family tree also implies that Anthozoa are the cnidarians most ...
Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ... Venom, Chironex; Venom, Cnidarian; Venom, Jellyfish; Venom, Portuguese Man-of-War; Venom, Sea Anemone; Venoms, Chironex; Venoms ... Chironex Venom; Cnidarian Venom; Jellyfish Venom; Portuguese Man-of-War Venom; Sea Anemone Venom; Portuguese Man of War Venom; ... Cnidarian; Venoms, Jellyfish; Venoms, Nematocyst; Venoms, Sea Anemone; Chironex Venoms; Jellyfish Venoms; Nematocyst Venoms; ...
Several cnidarian venoms have been found to have cytotoxic properties and have been also shown to cause hemolytic effects. Some ... During the last decades, the mechanisms of cell injury caused by cnidarian venoms have been studied utilizing extracts from ... The review aims to emphasize the up-to-date knowledge about this subject taking in consideration the importance of such venoms ... established cell lines or primary cultures have been employed to test cnidarian extracts or derivatives. ...
All cnidarians extracts tested inhibited the hemorrhagic activity induced by B. moojeni venom at a ratio of 1:30 w/w, showing ... However, all cnidarian extracts except M. alcicornis inhibited the coagulant activity induced by B. jararacussu venom at the ... Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All ... The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; ...
Cnidarian Venoms * toxin II (Anemonia sulcata) * Sodium * Calcium-Calmodulin-Dependent Protein Kinase Type 2 ...
Cytotoxic and Cytolytic Cnidarian Venoms. A Review on Health Implications and Possible Therapeutic Applications ...
Hemolytic venoms from marine cnidarian jellyfish - an overview. July 23, 2014adminJournal of Venom Research, Volume 5 ... Enzymatic analysis of venom from Cuban scorpion Rhopalurus junceus. July 22, 2015adminJournal of Venom Research, Volume 6 ... Neuromuscular activity of Bothrops fonsecai snake venom in vertebrate preparations. June 18, 2014adminJournal of Venom Research ... Peptides with in vitro anti-tumor activity from the venom of the Eastern green mamba, Dendroaspis angusticeps (Elapidae). June ...
Cnidarian Venoms / antagonists & inhibitors * Epinephrine / therapeutic use * Female * Fish Venoms / antagonists & inhibitors ... Premedication, Adverse Reactions and the Use of Venom Detection Kits Med J Aust. 1992 Dec 7-21;157(11-12):734-9. ... The value of snake venom detection kits (VDKs) was also analysed. Methods: Information was obtained from antivenom usage ...
Cnidarian Toxins and Venoms. 54 (8): 1071-1074. doi:10.1016/j.toxicon.2009.02.027. ISSN 0041-0101. PMID 19268681. da Silva, ... Venom is a type of poison, especially one secreted by an animal. Venom has evolved in a wide variety of animals, both predators ... Snake venom may have originated with duplication of genes that had been expressed in the salivary glands of ancestors. Venom is ... Venoms cause their biological effects via the toxins that they contain; some venoms are complex mixtures of toxins of differing ...
Cnidarian Venoms / Crotalid Venoms Limits: Animals Language: English Journal: J. venom. anim. toxins incl. trop. dis Journal ... Animals , Male , Rats , Antivenins/toxicity , Cnidarian Venoms/pharmacology , Crotalid Venoms/immunology , Bothrops , Neoplasms ... All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body ... The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; ...
All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body ... The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; ... Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. ... these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms. ...
0 (Cnidarian Venoms); 0 (Luminescent Proteins); 0 (Proteome); 0 (ShK neurotoxin); 0 (red fluorescent protein); EC 1.11.1.15 ( ... Zinc Metalloproteinase was previously reported in the venom of other jellyfish species. Besides the proteins described above, ...
0 (Cnidarian Venoms); 0 (Nerve Tissue Proteins); 0 (Neurotoxins). [Em] M s de entrada:. 1702. ... The total amount of venom discharged into sting-site tissues, sometimes referred to as "venom load", has been previously shown ... Its venom is a complex mixture of biologically active compounds that are used to catch prey. In order to evaluate the activity ... The crude venom and a fraction were observed to affect crustaceans and showed at least two types of bioactivity in oocytes ...
Some cnidarian venoms have little effect on humans. Others are extremely toxic. The venom of the Portuguese man-of-war ( ... Small anemone-like cnidarians like Hydra sp. are also found in freshwater lakes and streams. Cnidarians range in size from tiny ... Cnidarians have a slightly more organized body plan, and have tissues, but no organs. Most cnidarians have two tissue layers. ... Many cnidarians take two main structural forms during their life cycles, a polyp form and a medusa form. The polyp form has a ...
Cytotoxic and Cytolytic Cnidarian Venoms. A Review on Health Implications and Possible Therapeutic Applications Gian Luigi ... Neuromuscular Activity of Micrurus laticollaris (Squamata: Elapidae) Venom in Vitro Alejandro Carbajal-Saucedo,Rafael Stuani ... AaeAP1 and AaeAP2: Novel Antimicrobial Peptides from the Venom of the Scorpion, Androctonus aeneas: Structural Characterisation ...
Cnidarian Venoms and Alternative Research Methods: From Cell Damage to Possible Applications => pp. 257-276 (Gian Luigi ... Cnidarian jellyfish are among the most elegant and dazzling organisms inhabiting the global aquatic environment, due to their ...
Venom from animals such as cnidarians, scorpions and spiders may be species-specific. A substance that is weakly toxic for ... This prevents the cnidarian from stinging itself although sloughed off cnidae can be induced to fire independently. Over 30 ... Other cnidarians, such as the jellyfish Cyanea capillata (the "Lions Mane" made famous by Sherlock Holmes) or the siphonophore ... Brinkman D, Burnell J (November 2007). "Identification, cloning and sequencing of two major venom proteins from the box ...
Toxin peptides from other cnidarian venoms, like sea anemones, target sodium and potassium voltage-gated channels. In this ... A Purified Palythoa Venom Fraction Delays Sodium Current Inactivation in Sympathetic Neurons Toxicon : Official Journal of the ... Little is known on the pharmacological and biochemical properties of the venom components of this animal group. ... study, we tested the activity of a low molecular weight fraction from the venom of P. caribaeorum on voltage-gated sodium ...
In many cnidarians, these nematocysts contain powerful venoms that can be used for defense or to capture prey. ... Cnidarians are characterized by radial symmetry and the presence of stinging cells called cnidocytes that are used for the ... Cnidarians are have two true tissue layers (an outer epidermis and an inner gastrodermis) separated by a connective tissue ... Two body types are seen in cnidarians; the polyp is a sessile, cylindrical form in which the oral end (mouth and tentacles) is ...
In most Cnidarians, a "nettle" has evolved for effective injection of venom into the prey. Such a device is found in jellyfish ... Understanding and utilising mammalian venom via a platypus venom transcriptome. J. Proteomics 2009, 72, 155-164. [Google ... The Cnidarian Short Proteome. Currently, there are over 83,000 known proteins for the different branches of Cnidaria. Most of ... Several venom components evolved via convergent evolution [43]. Our study confirms that the phenomenon of genetic expansion and ...
What are the therapeutic uses for Australian box jellyfish venom?. Cnidarian venoms have been investigated as a potential ... Lee H, Kwon YC, Kim E. Jellyfish venom and toxins: a review. In: Gopalakrishnakone P, Haddad Jr. V, Kem WR, Tubaro A, Kim E ( ... Heat is not recommended as part of standard treatment, although it can reduce the venom lethality when maintained at over 43 C ... The venom is spread by tiny nematocysts, each containing picograms (trillionths of a gram) of proteins. ...
Natural Compounds and Drug Discovery: Can Cnidarian Venom Play a Role? Volume: 19 Issue: 2 Pp: 114-118 Gian Luigi Mariottini* ...
Natural Compounds and Drug Discovery: Can Cnidarian Venom Play a Role?. Central Nervous System Agents in Medicinal Chemistry ...
The actives inhibit venom induced hemolysis of all cnidarian venoms tested (Chironex, carbydeids, Cyanea physalia etc). The ... Angel Yanagihara is a research professor at the University of Hawaii and has been studying the venom of box jellyfish for over ... Her own life-threatening encounter in 1997 prompted her interest in box jelly venoms. "I got stung, and there was no useful ...
Cnidarian Venoms. Papers overview. Semantic Scholar uses AI to extract papers important to this topic. ...
Like all cnidarians, cubozoans possess nematocysts, cells that fire a barb and transfer venom. When a nematocyst contacts ... The larval stage of Cnidarians is called the planula and it is a free swimming developmental stage. Cubozoan planulae are pear- ... something that might be prey or predator, the barb uncoils and fires from the capsule along with toxic venom. Magnification ... This box jellyfish belongs to the Cubozoa group of Cnidarians. ... Like all cnidarians, cubozoans possess nematocysts, cells that ...
15] Motor and sensory neurotoxic effects of cnidarian venoms have been reported in several cases of mononeuritis multiplex ...
Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor local irritation to death. Here, ... The venom of C. fleckeri was found to be more lethal against Artemia sp. than the venom of the other species, consistent with ... Carybdea xaymacana; Chiropsalmus sp.; Chironex fleckeri; Cnidarian venoms; haemolysis; jellyfish; lethality; verapamil. ... Haemolytic activity was observed for all venoms, with C. xaymacana venom displaying the greatest activity. These activities are ...
Motor and sensory neurotoxic effects of cnidarian venoms have been reported in several cases of mononeuritis multiplex produced ... The venom of the Chrysaora spp. has been demonstrated to cause calcium ion influx through voltage-gated channels and cause ... Sympathomimetic action of the venom is known to cause severe hypertension in a syndrome commonly called the Irukandji, which is ... The venom also contains haemolytic and lethal fractions affecting the heart. 2 ...
The cnidarian Nematostella vectensis has become an established lab model, providing unique opportunities for venom evolution ...
  • Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. (scielo.br)
  • However, the toxins in many venoms have potential to treat a wide range of diseases. (wikipedia.org)
  • some venoms are complex mixtures of toxins of differing types. (wikipedia.org)
  • Cnidarians appear to have recruited as toxins the same kinds of proteins recruited by many other venomous animals. (grisda.org)
  • These peptides elicit a wide array of physiological effects in other fishes, though any one species examined produced no more than three distinct putative toxins in its venom. (biomedcentral.com)
  • The venom contains pore-forming (creating pores in cell membranes) toxins that are structurally similar to anthrolysin O, the pore-forming toxin produced by anthrax. (midweek.com)
  • The box jellyfish Chironex fleckeri can kill a full grown man in less than five minutes, and the venom it wields in its tentacles contains of some of the most rapid, potent toxins in the world. (discovermagazine.com)
  • Transcriptomes tell you which genes are actively being expressed, but it can be hard to tell which of those genes are actually acting as venom toxins and which are involved in day-to-day cellular maintenance. (discovermagazine.com)
  • Their tandem proteomic analyses specifically identified 13 of these that were in venom in relatively high abundance: seven proteases, four of which were metalloproteinases, an alpha-macroglobulin domain containing protein, two peroxiredoxin toxins, two CRISP proteins and a turripeptide-like protease inhibitor. (discovermagazine.com)
  • However, little is known about the molecular evolution of the venom toxins underlying these biological activities. (springer.com)
  • We report 132 venom proteins including putative enzymes, cytolytic toxins, and antimicrobial peptides. (springer.com)
  • Toxin synergism is a complex biochemical phenomenon, where different animal venom proteins interact either directly or indirectly to potentiate toxicity to a level that is above the sum of the toxicities of the individual toxins. (frontiersin.org)
  • Among the toxins that are known for interacting synergistically are cytotoxins from snake venoms, phospholipases A 2 from snake and bee venoms, and melittin from bee venom. (frontiersin.org)
  • In general, venoms derive their toxicity from proteins known as toxins. (frontiersin.org)
  • These toxins are in themselves a diverse and complex group, including smaller neurotoxic peptides, larger phospholipases, and venom proteases, along with many other protein families ( Ducancel, 2016 ). (frontiersin.org)
  • have evolved to produce venoms with potencies that are larger than the sum of the individual toxins (toxin synergism). (frontiersin.org)
  • Venomous animals such as cnidarians, scorpions, and snakes utilize their toxins for a diversity of functions including defense from predators and for capturing prey. (bco-dmo.org)
  • Moreover, toxins are energetically expensive to produce so it is also hypothesized that their production is tightly regulated ("venom optimization hypothesis"), where individuals can module the amount and composition of their venom dependent on changes in diet and shifts in environmental factors such as temperature. (bco-dmo.org)
  • Hessinger DA (1988) Nematocyst venom and toxins. (els.net)
  • Cases of jellyfish envenomation in Malaysia and some cytotoxic studies on their toxins, in (N.H. Tan, S.L. Oo, V. Thambyrajah, N. Azila, Herausgeber) Advances in Venom and Toxin Research. (gifte.de)
  • In: Marine Toxins and Venoms, Handbook of Natural Toxins (A.T. Tu, Herausgeber), Bd. (gifte.de)
  • Venom has evolved in a wide variety of animals, both predators and prey, and both vertebrates and invertebrates. (wikipedia.org)
  • Venoms adapt to their environment and victims and accordingly evolve to become maximally efficient on a predator's particular prey (particularly the precise ion channels within the prey). (wikipedia.org)
  • Bees synthesize and employ an acidic venom (apitoxin) to cause pain in those that they sting to defend their hives and food stores, whereas wasps use a chemically different alkaline venom designed to paralyze prey, so it can be stored alive in the food chambers of their young. (wikipedia.org)
  • When the nematocyst senses food either through touch or chemoreception, it fires outward, injecting venom through its tube into the prey (Fig. 3.26). (hawaii.edu)
  • When a nematocyst contacts something that might be prey or predator, the barb uncoils and fires from the capsule along with toxic venom. (sciencephoto.com)
  • Not only does it inject the prey with venom, but the small harpoon fixes it to the tentacle, preventing it from escaping and dying elsewhere. (scienceblogs.com)
  • Spiders have evolved pharmacologically complex venoms that serve to rapidly subdue prey and deter predators. (biomedcentral.com)
  • These venoms have evolved to serve a variety of purposes, including prey capture, competitor deterrence, and defense against predators. (biomedcentral.com)
  • Cnidocyst, sine qua non of cnidarian, is used for defense and prey. (cmas.org)
  • Despite being morphologically simple, lacking a skeleton and many species being sessile , cnidarians prey on fish and crustaceans . (wikipedia.org)
  • The specific representation of cnidae is referred to as the cnidome of that species and may represent a dynamic aspect of the cnidarian species that is responsive to prey availability or the developmental stage of the organism. (wikipedia.org)
  • In particular, some taxa within Cladobranchia possess the ability to sequester nematocysts from their cnidarian prey. (biomedcentral.com)
  • Most cnidarians prey on organisms ranging in size from plankton to animals several times larger than themselves, but many obtain much of their nutrition from dinoflagellates , and a few are parasites . (wikipedia.org)
  • Cnidarians are distinguished from all other animals by having cnidocytes that fire like harpoons and are used mainly to capture prey. (wikipedia.org)
  • Like all other cnidarians, cubozoans possess nematocysts (stinging organelles) essential for prey capture and defense. (beds.ac.uk)
  • To expand our capacity to discover venom sequences from the genomes of venomous organisms, we applied targeted sequencing techniques to selectively recover venom gene superfamilies and non-toxin loci from the genomes of 32 cone snail species (family, Conidae), a diverse group of marine gastropods that capture their prey using a cocktail of neurotoxic peptides (conotoxins). (readbyqxmd.com)
  • Despite remarkable inter- and intra-species variability, defined sets of synergistic venom peptides (cabals) are considered essential for prey capture by cone snails. (readbyqxmd.com)
  • This provides the animals possessing venoms with synergistically enhanced toxicity with a metabolic advantage, since less venom is needed to inflict potent toxic effects in prey and predators. (frontiersin.org)
  • Expression of venom genes in field collected anemones will be correlated with ingested prey identified using microscopy and DNA barcodes. (bco-dmo.org)
  • The rapid activity of the injected neurotoxins immediately paralyzes the mobile prey, thus allowing the sessile cnidarian to devour it. (wikidoc.org)
  • But venom from animals such as cnidarians, scorpions and spiders may be species-specific: a substance that is weakly toxic for humans or other mammals may be very toxic to the natural prey or predators of the venomous animal. (wikidoc.org)
  • Venoms are produced by a wide variety of species including spiders, scorpions, reptiles, cnidarians, and fish for the purpose of harming or incapacitating predators or prey. (edu.au)
  • When the tentacles capture a prey item, they contract, and the rings allow for maximum contact and transfer of venom between nematocyst and prey. (berkeley.edu)
  • The venom is spread by tiny nematocysts, each containing picograms (trillionths of a gram) of proteins. (dermnetnz.org)
  • Like all cnidarians, cubozoans possess nematocysts, cells that fire a barb and transfer venom. (sciencephoto.com)
  • Venom extracted from nematocysts of mature Chironex fleckeri specimens was exposed to temperatures between 4°C and 58°C for periods of two, five or 20 minutes, and then injected into freshwater crayfish ( Cherax quadricarinatus ) to assess lethality. (mja.com.au)
  • 4 Nematocysts were then ruptured with a bead mill beater to release venom. (mja.com.au)
  • Crude venom from nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa) elicits a sodium conductance in the plasma membrane of mammalian cells. (pubfacts.com)
  • Unlike snakes or spiders, jellyfish cannot be 'milked' - so the team had to separate nematocysts from fresh tentacles, make them "sting", and then separate the venom excreted from the capsule itself. (discovermagazine.com)
  • Another distinctive feature of Portuguese man-of-wars, as well as all Cnidarians are stinging organelles called nematocysts. (ambergriscaye.com)
  • Within Nudipleura, nudibranchs within Cladobranchia possess such a special defense: the ability to sequester cnidarian nematocysts - small capsules that can inject venom into the tissues of other organisms. (biomedcentral.com)
  • Cnidarians such as jellyfish and corals have stinging cells called nematocysts. (howstuffworks.com)
  • The body plans cnidarians generally have radial symmetry (Fig. 3.25 A). Because the tentacles of corals, jellyfish, and sea anemones have this radial structure, they can sting and capture food coming from any direction. (hawaii.edu)
  • Additionally, two groups of cnidarians, corals and sea anemones, exhibit six- or eight-fold symmetry. (thoughtco.com)
  • The more familiar polyp cnidarians include corals, hydras, and sea anemones. (thoughtco.com)
  • Laboratory work demonstrates that the venom porin ― porins are in all cnidarians, from anemones to corals to jellyfish, and the most rapid acting and potent porins are in the cubozoa or box jellies ― is irreversibly inhibited by heat. (midweek.com)
  • The sea anemone is a member of a 10,000-strong group of simple animals called the cnidarians, whose ranks also include jellyfish and corals. (scienceblogs.com)
  • While reef-forming corals are almost entirely restricted to warm and shallow marine waters, other cnidarians can be found at great depths, in polar regions , and in freshwater. (wikipedia.org)
  • [7] Fossil cnidarians have been found in rocks formed about 580 million years ago , and other fossils show that corals may have been present shortly before 490 million years ago and diversified a few million years later. (wikipedia.org)
  • Due to the role of corals in the carbon and calcium cycles, various aspects of cnidarian calcification are discussed. (nhbs.com)
  • Among the major classes of toxin in venoms are: Necrotoxins, which cause necrosis (i.e., death) in the cells they encounter. (wikipedia.org)
  • These activities are consistent with the presence of a pore-forming toxin existing in the venoms which has been demonstrated by transmission electron microscopy in the case of C. fleckeri. (edu.au)
  • Beyond the level of sequence mutation, dramatic changes in venom activity and composition may reflect rapid changes in expression levels of toxin-encoding genes, i.e., in the recruitment of new proteins into venom or their loss or downregulation. (springer.com)
  • His chemical strategies have been instrumental in unravelling the complexity of cone snail venoms and developing toxin structure activity relationships using new synthetic chemistry as well as toxin re-engineering to form more stable peptidomimetics suitable for commercialisation. (edu.au)
  • In the present study, nematocyst-derived venom from A. nr mordens (150-250 ?g/kg, i.v.) produced a long-lasting pressor effect in anaesthetised rats. (edu.au)
  • In each is a structure called a nematocyst which contains the venom and a harpoon-like structure on a biological thread. (discovermagazine.com)
  • The red dye stains the polyanionic venom proteins found inside the capsule of this partially-discharged nematocyst. (wikipedia.org)
  • During ingestion of cnidarian tissues, the cnidocyte (the cell) is separated from its nematocyst (the organelle). (biomedcentral.com)
  • The stinging cells, or cnidocysts, of sea anemones, jellyfish and other cnidarians contain a coiled hollow thread that unravels rapidly when triggered by physical contact - so rapidly that the pressure on the tip can theoretically reach nearly 7 gigapascals (PDF) , higher than the pressure needed to form diamonds within the Earth's mantle. (newscientist.com)
  • Unlike some of the better known groups of venomous animals such as snakes and spiders, however, or even their fellow cnidarians the Australian box jellyfish or Irukandji, which (quite appropriately) attract considerable public attention [ 8 , 9 ], the potentially harmful consequences of contact with sea anemones are relatively unknown. (mdpi.com)
  • along with scorpions and stinging insects, which inject venom with a sting. (wikipedia.org)
  • Venoms from marine and terrestrial animals (cone snails, scorpions, spiders, snakes, centipedes, cnidarian, etc.) can be seen as untapped cocktails of biologically active compounds that are being increasingly recognized as a new emerging source of peptide-based therapeutics. (doabooks.org)
  • Cnidaria (Gr., cnidae , nettle) is a phylum of mostly marine Metazoa distinguished by cnidocysts, subcellular capsules containing an inverted tubule capable of everting and, in some cases, discharging venom. (els.net)
  • Western blot analysis using CSL box jellyfish antivenom indicated several antigenic proteins in A. nr mordens venom, however, it did not detect all proteins present in the venom. (edu.au)
  • Again, since box jelly venom contains these pore-forming proteins that act very quickly to break open blood cells, releasing epinephrine, and is not an IgE-based allergy, use of an EpiPen (for injecting epinephrine or adrenaline to treat serious allergic reactions) is reportedly contraindicated and can lead to dangerous paradoxical effects. (midweek.com)
  • And while there's still more to learn, last week, a research team from Queensland, Australia published the most extensive analysis of Chironex venom proteins to date, revealing some of the diverse arsenal that these gelatinous killers are equipped with. (discovermagazine.com)
  • The team's goal was to perform the most in-depth analysis of Chironex venom to date, producing both a proteome (a library of the proteins present) and a transcriptome (a library of which genes are expressed). (discovermagazine.com)
  • While they could have used either the genetic or proteomic approaches to look at venom proteins, the combination was particularly powerful. (discovermagazine.com)
  • Over 73% (96 proteins) showed homology to venom proteins from assassin bugs (Reduviidae), including 21% (28 proteins from seven families) not known from other sources. (springer.com)
  • While there is abundant evidence that snake venoms evolved by recruitment of genes encoding normal body proteins followed by extensive gene duplication accompanied by explosive structural and functional diversification, the evolutionary trajectory of spider-venom peptides is less clear. (biomedcentral.com)
  • Their venoms are complex cocktails of toxic proteins, peptides, and small organic and inorganic molecules. (frontiersin.org)
  • This project will provide a synergistic international collaboration with Dr. Yehu Moran (The Hebrew University of Jerusalem, Israel) to connect environmental variation with the expression and potency of venom proteins. (bco-dmo.org)
  • In common with many other venomous animals, they produce venom that is a complex mixture of small molecules, peptides and proteins [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. (mdpi.com)
  • A functional comparison of the venom of three Australian jellyfish-Chironex fleckeri, Chiropsalmus sp. (edu.au)
  • To determine the effect of temperature on lethality of venom from Chironex fleckeri (the potentially fatal box jellyfish). (mja.com.au)
  • 1 The venom from Chironex fleckeri , a large box jellyfish (pictured above), is also sensitive to temperature, with decreased activity after prolonged exposure (days to months) to temperatures between -10ºC and 5ºC, 2 , 3 and complete loss of activity after much shorter exposure (minutes) to 45ºC. (mja.com.au)
  • Cytotoxins, which kill individual cells, are found in the apitoxin of honey bees and the venom of black widow spiders. (wikipedia.org)
  • these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms. (scielo.br)
  • Myotoxins, which damage muscles by binding to a receptor, are small, basic peptides found in snake (such as rattlesnake) and lizard venoms. (wikipedia.org)
  • The value of snake venom detection kits (VDKs) was also analysed. (nih.gov)
  • Snake venoms are complex mixtures of molecules possessing various biological functions. (biomedcentral.com)
  • The venom acts more like a snake venom and causes cellular destruction. (midweek.com)
  • This 'venomic' approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. (readbyqxmd.com)
  • From a molecular evolutionary perspective, the venoms of snakes are the best understood. (biomedcentral.com)
  • Small anemone-like cnidarians like Hydra sp. (hawaii.edu)
  • Most people know jellyfish and their ilk -- the cnidarians, of sea pen, anemone, coral, and man'o'war fame -- live in water and (happily for us) stay pretty well confined to it. (scientificamerican.com)
  • The threads normally inject venom into the target of the animal's attack. (newscientist.com)
  • This box jellyfish belongs to the Cubozoa group of Cnidarians. (sciencephoto.com)
  • Venomous animals are considered to be specialized predators that have evolved the most sophisticated peptide chemistry and neuropharmacology for their own biological purposes by producing venoms that contain a structural and functional diversity of neurotoxins. (doabooks.org)
  • However, the production and replenishment of these venoms come with a metabolic cost for the venomous animals ( Morgenstern and King, 2013 ). (frontiersin.org)
  • The venom of most viper species contains phospholipase and trypsin-like serine proteases. (wikipedia.org)
  • Many caterpillars have defensive venom glands associated with specialized bristles on the body, known as urticating hairs, which can be lethal to humans (e.g., that of the Lonomia moth), although the venom's strength varies depending on the species. (wikipedia.org)
  • At least one ant species (Polyrhachis dives) has been shown to use venom topically for the sterilisation of pathogens. (wikipedia.org)
  • than the venom of the other species, consistent with the order of known human toxicities. (edu.au)
  • Catfishes (Order Siluriformes) are a diverse group of bony fishes that have long been known to include venomous taxa, but the extent and phylogenetic distribution of this venomous species diversity has never been documented, while the nature of the venoms themselves also remains poorly understood. (biomedcentral.com)
  • In this study, I used histological preparations from over 100 catfish genera, basic biochemical and toxicological analyses of fin spine extracts from several species, and previous systematic studies of catfishes to examine the distribution of venom glands in this group. (biomedcentral.com)
  • A number of putative toxic peptides were identified in the venoms of catfish species from many of the families determined to contain venomous representatives. (biomedcentral.com)
  • Despite the economic and medical impact that this jellyfish has on Australia (and similar species world-wide) we know very little about what is exactly in the venom," explained Jason Mulvenna, Team Head of Infectious Disease and Cancer at QIMR Berghofer Medical Research Institute and coauthor of the paper published in BMC Genomics . (discovermagazine.com)
  • Many cnidarian species produce colonies that are single organisms composed of medusa-like or polyp-like zooids, or both (hence they are trimorphic ). (wikipedia.org)
  • Not all cnidarians reproduce sexually , with many species having complex life cycles of asexual polyp stages and sexual medusae. (wikipedia.org)
  • Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. (readbyqxmd.com)
  • Venoms are produced for defensive and/or predatory purposes to provide a survival benefit to the species possessing them. (frontiersin.org)
  • Jellyfish species (of the cnidarian subphylum Medusozoa) typically possess a benthic, sessile stage (polyp) that reproduces asexually by budding new polyps or medusae, the latter of which represent the sexually reproductive stage of the textbook medusozoan life cycle. (thefreelibrary.com)
  • The box jellyfish is an order of cnidarian invertebrates, of which there are two orders, eight families and fifty-one known species. (howstuffworks.com)
  • and Hydrozoa , a diverse group that includes all the freshwater cnidarians as well as many marine forms, and has both sessile members, such as Hydra , and colonial swimmers, such as the Portuguese Man o' War . (wikipedia.org)
  • Cell cycle analysis and changes of the mitochondrial membrane potential shows the cell cycle arrest at G1 phase which confirmed the potential anticancer activity of jellyfish venom against human breast cancer cell MDA-MB 231. (isindexing.com)
  • Black widow spider, scorpion, box jellyfish, cone snail, centipede and blue-ringed octopus venoms (among many others) function in this way. (wikipedia.org)
  • Venomics-Accelerated Cone Snail Venom Peptide Discovery. (readbyqxmd.com)
  • Cone snail venoms are considered a treasure trove of bioactive peptides. (readbyqxmd.com)
  • Cone snail venoms have separately evolved for predation and defense. (readbyqxmd.com)
  • Conorfamides are a poorly studied family of cone snail venom peptides with broad biological activities, including inhibition of NMDA receptors, acid-sensing ion channels, voltage-gated potassium channels, and ligand-gated glutamate receptors. (atgcchecker.com)
  • The aim of this study was to characterise the pharmacological activity of two novel linear conorfamides (conorfamide_As1a and conorfamide_As2a) and their non-amidated counterparts (conopeptide_As1b and conopeptide_As2b) that were isolated from the venom of the Mexican cone snail Conus austini. (atgcchecker.com)
  • 15] Motor and sensory neurotoxic effects of cnidarian venoms have been reported in several cases of mononeuritis multiplex produced by different jellyfish [16] Few reports of Guillain-Barre syndrome and dysphonia following jellyfish stings have also been reported. (thefreedictionary.com)
  • These organelles contain irritating poisons, and are armed with sharp hollow threads that deliver venom causing painful stings. (biomedcentral.com)
  • With one exception, systemic signs of envenoming following cnidarian stings occur more or less immediately after the sting. (vapaguide.info)
  • Independent of the aetiology, common to all serious cnidarian stings is the possibility that a critical, life-threatening situation may arise within a very short time following the sting. (vapaguide.info)
  • One strategy to solve this problem is to train paramedics in the initial treatment of cnidarian stings . (vapaguide.info)
  • This is responsible for the stings delivered by a cnidarian. (wikipedia.org)
  • Other cnidarians, such as the jellyfish Cyanea capillata (the " The Adventure of the Lion's Mane " made famous by Sherlock Holmes ) or the hydrozoan Physalia physalis ( Portuguese Man o' War , "Bluebottle") can cause extremely painful and sometimes fatal stings. (wikidoc.org)
  • Natural Compounds and Drug Discovery: Can Cnidarian Venom Play a Role? (eurekaselect.com)
  • Conclusion: These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer. (bvsalud.org)
  • Pain-inducing or "algesic" venom compounds have proven invaluable to our understanding of how physiological nociceptive neural networks operate. (edu.au)
  • Cnidarians have a unique feature: stinging cells called cnidocytes (NID-uh-sites). (hawaii.edu)
  • However, little is known about the anti-tumor activity of the active components of P. noctiluca venom and their mechanism of action on cancer cells remains unknown. (biomedcentral.com)
  • Thus, this study attempts, for the first time to characterize and evaluate the exact role of P. noctiluca venom and its semi-purified fractions on (i) viability of human glioblastoma cells (U87), (ii) cell proliferation and (iii) cell adhesion to immobilized extracellular matrix (ECM) protein (fibrinogen). (biomedcentral.com)
  • When a spine enters a potential predator, the integument surrounding the venom gland cells is torn, releasing venom into the wound. (biomedcentral.com)
  • These include epitheliomuscular cells which contract and enable movement, interstitial cells that give rise to many other cell types such as egg and sperm, cnidocytes which are specialized cells unique to cnidarians which in some cnidarians contain stinging structures, mucus-secreting cells which glandular cells that secrete mucus, and receptor and nerve cells which collect and transmit sensory information. (thoughtco.com)
  • Cnidocytes are specialized cells located in the epidermis of all cnidarians. (thoughtco.com)
  • These cells are unique to cnidarians, no other organism possesses them. (thoughtco.com)
  • Blundering into the waving tentacles, the fish is stung by hundreds of tiny harpoons shot out from stinging cells, each one loaded with potent venom. (scienceblogs.com)
  • Venom is delivered through the creature's tentacles, which attacks the heart, nervous system and skin cells, and causes excruciating pain. (howstuffworks.com)
  • Like other cnidarians , cubozoans are composed of two layers of cells, ectoderm and endoderm . (berkeley.edu)
  • The major toxic factors in most spider venoms are small, disulfide-rich peptides. (biomedcentral.com)
  • The composition of cnidarian venoms remains incompletely elucidated. (scielo.br)
  • I did a basic literature search for biochemical publications and was surprised that little was known about the potentially lethal box jellyfish venom or its composition. (midweek.com)
  • Scientists have been trying to determine the composition of box jelly venom for decades, but have only uncovered some of its potent constituents . (discovermagazine.com)
  • In contrast, trophic switches to blood-feeding (e.g. in Triatominae and Cimicidae) or reversions to plant-feeding (e.g., in Pentatomomorpha) were accompanied by rapid changes in the composition of venom/saliva, including the loss of many protein families. (springer.com)
  • The composition of an animal's venom evolves dynamically within its larger ecological context. (springer.com)
  • Complete loss or gain of venom use (i.e., changes in whether a secretion is used for envenomation or not) unsurprisingly entails marked consequences for the evolution of its composition over time. (springer.com)
  • Heteropteran insects are an ideal group in which to explore how large changes in trophic strategy-for example between phytophagy, entomophagy, and haematophagy, and including complete loss or gain of venom use-co-evolve with the composition of a venom/saliva secretion. (springer.com)
  • This research will provide an integrative approach to identify mechanisms that determine shifts in the quantity and composition of the venom essential for the feeding ecology of a model cnidarian specializing in estuarine habitats that are vulnerable to the ongoing climate change. (bco-dmo.org)
  • While some venoms are of relatively simple composition, many contain hundreds to thousands of individual components with distinct pharmacological activity. (edu.au)
  • Cubozoans (box jellyfish) are cnidarians that have evolved a number of distinguishing features. (beds.ac.uk)
  • Furthermore, we annotated a large set of candidate genes putatively involved in venom, vision and sex, providing an initial molecular characterization of these complex features in cubozoans. (beds.ac.uk)
  • This new genomic resource and the candidate gene dataset are valuable for further investigating the evolution of distinctive features of cubozoans, and of cnidarians more broadly. (beds.ac.uk)
  • Finally, it is worth mentioning in case you go on to read more about cubozoans (or any other cnidarians for that matter) that the plains of symmetry in a cubozoan have special names. (berkeley.edu)
  • The poison is found in the fish's muscle tissue which is as toxic as the blue-ringed octopus' venom. (howstuffworks.com)
  • All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. (scielo.br)
  • All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. (scielo.br)
  • Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. (bvsalud.org)
  • Some cnidarians go through both a polyp and medusa phase in their life cycle. (hawaii.edu)
  • Cnidarians range in size from tiny animals no bigger than a pinhead to graceful giants with trailing tentacles several meters long. (hawaii.edu)
  • The tentacles of cnidarians have cnidocytes embedded within them. (thoughtco.com)
  • One of the deadliest venoms in the world can be found in the flimsy tentacles of this box jellyfish. (discovermagazine.com)
  • To construct a 'proteome', the team had to isolate venom from the jelly tentacles. (discovermagazine.com)
  • Cellular organelles in the form of stinging capsules present in the tentacles of cnidarians, with the ability to shoot a microscopic harpoon that injects venom as a defense method. (opistobranquis.info)
  • Our experiments have indicated that the separation of the Mediterranean jellyfish Pelagia noctiluca crude venom extract by sephadex G-75 chromatography led to four fractions (F1, F2, F3, and F4). (biomedcentral.com)
  • Separation by sephadex G-75 chromatography give rise to more active fractions than the crude venom extract. (biomedcentral.com)
  • Objective: The present investigation is made to evaluate the efficiency of the crude venom of jellyfish Acromitus flagellates, a cnidarian for its antiproliferative activity. (isindexing.com)
  • The crude venom of nematocystm was tested against anticancer potential on human breast cancer cell lines (MDA-MB-231) with 200 ?g IC50. (isindexing.com)
  • Results: The protein content of the crude venom was estimated to be 1.5 mg/ml. (isindexing.com)
  • The protein profile of crude venom protein was determined by SDS-PAGE and the molecular weight was found to be in the range of 205 kDa to 29 kDa. (isindexing.com)
  • The isolated crude venom was tested for its antiproliferative activity against human breast cancer cell line MDA-MB-231 by MTT assay. (isindexing.com)
  • The results revealed that the crude venom showed antiproliferative activity at an IC 50 concentration of 200 g/ml. (isindexing.com)
  • Other insects, such as true bugs and many ants, also produce venom. (wikipedia.org)
  • True Bugs (Insecta: Heteroptera) produce venom or saliva with diverse bioactivities depending on their feeding strategies. (springer.com)
  • The larval stage of Cnidarians is called the planula and it is a free swimming developmental stage. (sciencephoto.com)
  • Like many cnidarians, cubozoan life history includes a swimming planula larva that ultimately settles onto a substrate to become an asexually reproducing polyp. (beds.ac.uk)
  • Cnidarians may negatively impact human activities and public health but concomitantly their venom represents a rich source of bioactive substances. (pubfacts.com)
  • Cnidarians comprise an old and diverse animal phylum, and possess a wide variety of biologically active substances. (bvsalud.org)
  • In severe cases, the venom causes systemic effects, including acute cardiovascular collapse and death in a matter of minutes or more delayed but potentially deadly symptoms - a condition known as Irukandji Syndrome. (discovermagazine.com)
  • The toxic peptides found in catfish venoms may be derived from epidermal secretions that have been demonstrated to accelerate the healing of wounds, rather than defensive crinotoxins. (biomedcentral.com)
  • Consequently, venoms become specialized to an animal's standard diet. (wikipedia.org)
  • Discovery and characterisation of novel low molecular weight bioactive peptides from Australian elapid venom. (edu.au)
  • This suggests that the observed lytic effects may not underlie the lethal effects of the venom, and raises the question of how such potent activities are dealt with by envenomed humans. (edu.au)
  • To conclude, we have demonstrated for the first time that Pelagia noctiluca venom and its fractions especially (F1 and F2) display potent anti-tumoral properties. (biomedcentral.com)
  • 5 Venom concentration in the resulting extract was assumed to be correlated with protein concentration, 6 which was determined by a Bradford Lowry assay. (mja.com.au)
  • Inside the cnidocyst, there is an inverted tubule, venom and a huge osmotic pressure. (cmas.org)
  • Venom lethality, assessed as time to cardiac standstill in crayfish after intramuscular injection. (mja.com.au)
  • At temperatures ≥ 43°C, venom lost its lethality more rapidly the longer the exposure time. (mja.com.au)
  • Exposure to heat dramatically reduces the lethality of extracted C. fleckeri venom. (mja.com.au)
  • We investigated the effect of exposing extracted C. fleckeri venom to a range of temperatures for different periods on its lethality in crayfish. (mja.com.au)
  • However, at temperatures of 43ºC and above, venom lost its lethality more rapidly the longer the exposure time ( Box 2 ). (mja.com.au)
  • The present study investigated the toxic effects of B. lienhardi venom, at the histological, hematological, biochemical and motor skill levels following a subcutaneous injection of different doses of venom. (readbyqxmd.com)
  • Cytotoxic and Cytolytic Cnidarian Venoms. (mdpi.com)
  • Kortschak RD, Samuel G, Saint R and Miller DJ (2003) EST analysis of the cnidarian Acropora millepora reveals extensive gene loss and rapid sequence divergence in the model invertebrates. (els.net)
  • It should be noted that cnidarians are not the only animals to exhibit radial symmetry. (thoughtco.com)
  • Fluorescens Anisotropi som værktøj til at studere protein-protein interaktioner Abril Gijsbers 1 , Takuya Nishigaki 2 , Nuria Sánchez-Puig 1 1 Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, 2 Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México Protein interaktioner er kernen i en celles funktion. (jove.com)
  • However, molecular clock analysis of mitochondrial genes suggests a much older age for the crown group of cnidarians, estimated around 741 million years ago , almost 200 million years before the Cambrian period as well as any fossils. (wikipedia.org)
  • Our approach of using multiple body parts and life stages to generate this transcriptome effectively identified a broad range of candidate genes for the further study of coordinated processes associated with venom, vision and sex. (beds.ac.uk)
  • Although both ctenophores and cnidarians have similar bodies with thin tissue layers enclosing a middle layer of jellylike material, scientists now group them separately. (hawaii.edu)
  • Cnidarians were formerly grouped with ctenophores in the phylum Coelenterata , but increasing awareness of their differences caused them to be placed in separate phyla. (wikipedia.org)
  • Cnidarians form an animal phylum that are more complex than sponges , about as complex as ctenophores (comb jellies), and less complex than bilaterians , which include almost all other animals. (wikipedia.org)
  • Hence, cnidarians and ctenophores have traditionally been labelled diploblastic , along with sponges. (wikipedia.org)
  • [9] [10] However, both cnidarians and ctenophores have a type of muscle that, in more complex animals, arises from the middle cell layer . (wikipedia.org)
  • The venom of C. fleckeri was found to be more lethal against Artemia sp. (edu.au)
  • Venom was non-lethal after exposure to 48°C for 20 minutes, 53°C for five minutes, and 58°C for two minutes. (mja.com.au)
  • Cnidarian envenomations are the leading cause of severe and lethal human sting injuries from marine life. (pubfacts.com)
  • In P. Gopalakrishnakone (Ed.), Scorpion venoms (pp. 547-561) Dordrecht, Netherlands: Springer. (edu.au)
  • The LD50 of B. lienhardi scorpion venom was found to be 0.27 mg/Kg by subcutaneous injection route. (readbyqxmd.com)
  • Many cnidarians take two main structural forms during their life cycles, a polyp form and a medusa form. (hawaii.edu)
  • The second structural form that cnidarians have is called the medusa form. (hawaii.edu)
  • Cnidarians take on two basic forms, a medusa and a polyp. (thoughtco.com)
  • Some cnidarians only exhibit the medusa form throughout their life while others first pass through other phases before maturing into the medusa form. (thoughtco.com)
  • Some cnidarians remain a polyp for their entire life, while others pass through the medusa body form. (thoughtco.com)
  • Cnidarians are a diverse group of invertebrates that come in many shapes and sizes but there are some basic features of their anatomy that most share in common. (thoughtco.com)