| multivariate species boundaries and conservation of harlequin poison frogs. | in this study, we present an iterative method for delimiting species under the general lineage concept (glc) based on the multivariate clustering of morphological, ecological and genetic data. our rationale is that distinct multivariate groups correspond to evolutionarily independent metapopulation lineages because they reflect the common signal of different secondary defining properties (environmental and genetic distinctiveness, phenotypic diagnosability, etc.) that imply the existence of barr ... | 2018 | 30033565 |
| a comparative study of synthetic approaches towards total synthesis of histrionicotoxin: a selective inhibitor of nicotinic acetylcholine receptors. | the aim of this review is to provide a critical and comparative account of the total synthetic approaches toward histrionicotoxins, alkaloids isolated from skin extracts of colombian poison arrow frog dendrobates histrionicus. we have summarized the maneuvers in each paper by graphically detailing the synthesis and associated reaction niceties of only the key intermediates by different researchers. fascinating structural feature of histrionicotoxins is "8-hydroxy-l-azaspiro[5.5]undecane core" wi ... | 2020 | 32835524 |
| adjusted phonotactic reactions to sound amplitude and pulse number mediate territoriality in the harlequin poison frog. | the information content of signals remains one of the central questions in animal communication. auditory signals might contain information that allows receivers to estimate the distance as well as the size or the motivational state of senders. proper differential reactions by receivers could be especially important for territorial species and lead to behavioural adjustments towards intruders according to the threat level: the perceived risk of losing territory. therefore, territorial individual ... | 2020 | 32971222 |
| helminths of two anuran species, atelopus spurrelli (bufonidae) and dendrobates histrionicus (dendrobatidae), from colombia, south america. | two species of anurans from colombia, south america, atelopus spurrelli and dendrobates histrionicus, were examined for helminths. a. spurrelli was found to harbor three species of nematoda, adults of cosmocerca podicipinus and larvae of physocephalus sp. and porrocaecum sp. d. histrionicus was found to harbor, in addition to c. podicipinus, physocephalus sp. and porrocaecum sp. and cystacanths of three species of acanthocephala: centrorhynchus sp., onicola sp. and polymorphus sp. a. spurrelli a ... | 2003 | 14550481 |
| interactions of gephyrotoxin with the acetylcholine receptor-ionic channel complex. i. blockade of the ionic channel. | the novel tricyclic alkaloid, gephyrotoxin ( gytx ), found in the skin secretions of the frog dendrobates histrionicus , potentiates and blocks the indirectly elicited muscle twitch in a concentration-dependent manner. gytx prolongs the falling phase of the muscle action potential and decreases delayed rectification, supporting the idea that the alkaloid blocks the voltage-sensitive potassium conductance of the electrically excitable membrane. the peak amplitude of the end-plate currents (epc) a ... | 1984 | 6328264 |
| alkaloids from dendrobatid frogs: structures of two omega-hydroxy congeners of 3-butyl-5-propylindolizidine and occurrence of 2,5-disubstituted pyrrolidines and a 2,6-disubstituted piperidine. | forty alkaloids were detected and characterized from skin extracts of high- and low-elevation populations of the poison frog dendrobates histrionicus from northwestern colombia. combined gc/ms with nh3 or nd3 in a chemical ionization mode detected protonated parent ions and determined the number of exchangeable nh and oh hydrogens. six previously unknown dendrobatid alkaloids were characterized. two were 2,5-disubstituted pyrrolidines, which included pyrrolidine 197b, a trans-2-butyl-5-pentylpyr ... | 2006 | 3734811 |
| diversification and convergence of aposematic phenotypes: truncated receptors and cellular arrangements mediate rapid evolution of coloration in harlequin poison frogs. | aposematic signals represent one of the classical systems to study evolution and, as such, they have received considerable empirical and theoretical investigation. despite the extensive literature on aposematic coloration, much uncertainty remains about genetic changes responsible for the repeated evolution of similar signals in multiple lineages. here, we study the diversification and convergence of coloration among lineages of aposematic harlequin poison frogs (oophaga histrionica complex). ou ... | 2017 | 28837761 |
| histrionicotoxins: roentgen-ray analysis of the novel allenic and acetylenie spiroalkaloids isolated from a colombian frog, dendrobates histrionicus. | the structures and absolute configuration of two unique alkaloids isolated from the colombian frog, dendrobates histrionicus, have been elucidated by roentgen-ray (x-ray) crystallography. histrionicotoxin is (2pr, 6s, 7ps, 8as)-7-(cis-1-buten-3-ynyl)-8-hydroxy-2-(cis-2-penten-4- ynyl)-1-azaspiro[5.5] undecane, while in dihydro-isohistrionicotoxin the acetylenic 2-pentenynyl side chain is replaced by an allenic 2-(3,4 pentadienyl) substituent. dendrobates histrionicus exhibits remarkable interpop ... | 1971 | 5288773 |
| allenic and acetylenic spiropiperidine alkaloids from the neotropical frog, dendrobates histrionicus. | | 1974 | 4443292 |
| gephyrotoxins, histrionicotoxins and pumiliotoxins from the neotropical frog dendrobates histrionicus. | | 1977 | 863724 |
| perhydrohistrionicotoxin: a potential ligand for the ion conductance modulator of the acetylcholine receptor. | histrionicotoxin from the colombian frog dendrobates histrionicus and its perhydro derivative reversibly block the acetylcholine-sensitive ion conductance system in frog neuromuscular preparations. the perhydro derivative and [3h]perhydrohistrionicotoxin, like histrionicotoxin, caused a significant decrease in the peak amplitude of the end-plate current and shortened its rise time and half-decay time. in membrane preparations from torpedo electroplax, [3h]perhydrohistrionicotoxin bound reversibl ... | 1977 | 301278 |
| voltage- and time-dependent action of histrionicotoxin on the endplate current of the frog muscle. | histrionicotoxin, a toxin isolated from skin secretions of a colombian arrow poison frog, dendrobates histrionicus, decreased the amplitude and time-course of the endplate current, and altered the voltage dependence of the half-decay time. in addition, the toxin produced a characteristic nonlinearity in the current-voltage relationship of the endplate current when 3-s voltage conditioning steps were used. reduction in time of the conditioning steps to 10 ms made the current-voltage relationship ... | 1978 | 308995 |
| stream noise, hybridization, and uncoupled evolution of call traits in two lineages of poison frogs: oophaga histrionica and oophaga lehmanni. | according to the acoustic adaptation hypothesis, communication signals are evolutionary shaped in a way that minimizes its degradation and maximizes its contrast against the background noise. to compare the importance for call divergence of acoustic adaptation and hybridization, an evolutionary force allegedly promoting phenotypic variation, we compared the mate recognition signal of two species of poison frogs (oophaga histrionica and o. lehmanni) at five localities: two (one per species) along ... | 2013 | 24194888 |
| hybridization promotes color polymorphism in the aposematic harlequin poison frog, oophaga histrionica. | whether hybridization can be a mechanism that drives phenotypic diversity is a widely debated topic in evolutionary biology. in poison frogs (dendrobatidae), assortative mating has been invoked to explain how new color morphs persist despite the expected homogenizing effects of natural selection. here, we tested the complementary hypothesis that new morphs arise through hybridization between different color morphs. specifically, we (1) reconstructed the phylogenetic relationships among the studi ... | 2013 | 24340180 |