Phylogeography of the Central American lancehead Bothrops asper (SERPENTES: VIPERIDAE)

The uplift and final connection of the Central American land bridge is considered the major event that allowed biotic exchange between vertebrate lineages of northern and southern origin in the New World. However, given the complex tectonics that shaped Middle America, there is still substantial controversy over details of this geographical reconnection, and its role in determining biogeographic patterns in the region. Here, we examine the phylogeography of Bothrops asper, a widely distributed pitviper in Middle America and northwestern South America, in an attempt to evaluate how the final Isthmian uplift and other biogeographical boundaries in the region influenced genealogical lineage divergence in this species. We examined sequence data from two mitochondrial genes (MT-CYB and MT-ND4) from 111 specimens of B. asper, representing 70 localities throughout the species' distribution. We reconstructed phylogeographic patterns using maximum likelihood and Bayesian methods and estimated divergence time using the Bayesian relaxed clock method. Within the nominal species, an early split led to two divergent lineages of B. asper: one includes five phylogroups distributed in Caribbean Middle America and southwestern Ecuador, and the other comprises five other groups scattered in the Pacific slope of Isthmian Central America and northwestern South America. Our results provide evidence of a complex transition that involves at least two dispersal events into Middle America during the final closure of the Isthmus

Genotypic diversity of Acanthamoeba strains isolated from Chilean patients with Acanthamoeba keratitis

Acanthamoeba spp. are the causative agents of a severe keratitis occurring mainly in contact lens wearers. The genus comprises more than 24 species that are currently divided into 20 different genotypes (T1-T20) according to sequence variations in the 18S rRNA gene. The objective of this study was to identify the genotypes and sub-genotypes of Acanthamoeba isolates collected at the Parasitology Laboratory of the Public Health Institute of Chile, the only laboratory in the country where Acanthamoeba screening is performed. This is the first report of genotypic identification of clinical isolates of Acanthamoeba in Chile and one of the few in South America. T2, T4 and T11 genotypes were predominantly isolated from the Acanthamoeba keratitis patients in Chile. Chilean predominant T4 sub-genotypes, which have also been reported worldwide, formed a separate cluster of the minority T4 variants. This study provides useful information about the predominant genotypes and subgenotypes that would be useful in selecting suitable strains to develop immunological and/or molecular diagnostic assays in Chile

Toxinological, clinical and epidemiological aspects of the envenomation produced by the scorpion Tityus fuhrmanni Kraepelin

Con el objetivo de determinar las características toxinológicas, clínicas y epidemiológicas del envenenamiento producido por el escorpión T. fuhrmanni, se realizó durante un año un estudio prospectivo en un sector de la ciudad de Medellín (cerro El Volador y los barrios aledaños San Germán y El Volador), en una muestra del9,6% de las casas (180) y del 9,4% de la población del área (719 habitantes). Se incluyó también la recolección de especímenes vivos (128) y de veneno para la parte experimental. La dispersión de escorpiones para el área de estudio fue del 100%, con alta infestación domiciliaria en las viviendas del cerro y del barrio San Germán (100% y 32,3%, respectivamente). Durante todo el estudio se detectaron 32 accidentes por T.fuhrmanni, 7 (21,9%) en niños, 15 en el cerro y 10 en el barrio San Germán, con tasas de ataque del 83% y del 3,9%, respectivamente. Dieciocho (56,3%) accidentes ocurrieron en el interior de las viviendas, principalmente en las manos (31,3%), la cabeza y el cuello (18,8%) y durante la noche o en las primeras horas de la mañana (62,5%). El 90,6% de los casos fueron leves y el 9,4% (3 niños) tuvieron envenenamiento moderado con signos sistémicos (sudoración generalizada, dolor abdominal). No hubo casos graves y los pacientes no requirieron hospitalización. Tityus fuhrmanni produjo 0,56 ± 0,27 mg de veneno por ordeño, ysu DL50 (i.p.) en ratones (18-20 g) fue 79,2 μg (3,9 mg veneno/kg). Los animales presentaron sialorrea, piloerección, somnolencia, sudoración generalizada, taquipnea, cianosis, ataxia y convulsiones antes de morir. La rápida aparición (10-15 min) de los signos de envenenamiento en los ratones y su pronta desaparición(2 horas) en los sobrevivientes, permiten concluir que el veneno es de rápida absorción, distribución y eliminación. [Gómez JP, Otero R, Núñez V, Saldarriaga M, Díaz A, Velásquez P. Aspectos toxinológicos, clínicos y epidemiológicos del envenenamiento producido por el escorpión Tityus fuhrmanni Kraepelin.MEDUNAB 2002; 5(15): 159-65]In order to determine the toxinological, clinical and epidemiological characteristics of the poisoning produced by the scorpion T. fuhrmanni, a prospective study was carried out for a year in a sector of the city of Medellín (Cerro El Volador and the neighboring neighborhoods San Germán and El Volador), in a sample of 9.6% of the houses (180) and 9.4% of the population of the area (719 inhabitants). The collection of live specimens (128) and poison for the experimental part was also included. The dispersion of scorpions for the study area was 100%, with high home infestation in the homes of the hill and the San Germán neighborhood (100% and 32.3%, respectively). Throughout the study, 32 accidents were detected by T. fuhrmanni, 7 (21.9%) in children, 15 in the hill and 10 in the San Germán neighborhood, with attack rates of 83% and 3.9%, respectively. . Eighteen (56.3%) accidents occurred inside homes, mainly in the hands (31.3%), head and neck (18.8%) and during the night or in the early hours of the morning (62.5%). 90.6% of the cases were mild and 9.4% (3 children) had moderate poisoning with systemic signs (generalized sweating, abdominal pain). There were no serious cases and the patients did not require hospitalization. Tityus fuhrmanni produced 0.56 ± 0.27 mg of venom per milking, and its LD50 (i.p.) in mice (18-20 g) was 79.2 μg (3.9 mg venom / kg). The animals presented with salivation, piloerection, drowsiness, generalized sweating, tachypnea, cyanosis, ataxia and seizures before dying. The rapid appearance (10-15 min) of the poisoning signs in the mice and their prompt disappearance (2 hours) in the survivors, allow us to conclude that the venom is of rapid absorption, distribution and elimination. [Gómez JP, Otero R, Núñez V, Saldarriaga M, Díaz A, Velásquez P. Toxinological, clinical and epidemiological aspects of the poisoning produced by the scorpion Tityus fuhrmanni Kraepelin.MEDUNAB 2002; 5 (15): 159-65

The macroecology of chemical communication in lizards: do climatic factors drive the evolution of signalling glands?

Chemical communication plays a pivotal role in shaping sexual and ecological interactions among animals. In lizards, fundamental mechanisms of sexual selection such as female mate choice have rarely been shown to be influenced by quantitative phenotypic traits (e.g., ornaments), while chemical signals have been found to potentially influence multiple forms of sexual and social interactions, including mate choice and territoriality. Chemical signals in lizards are secreted by glands primarily located on the edge of the cloacae (precloacal glands, PG) and thighs (femoral glands), and whose interspecific and interclade number ranges from 0 to >100. However, elucidating the factors underlying the evolution of such remarkable variation remains an elusive endeavour. Competing hypotheses suggest a dominant role for phylogenetic conservatism (i.e., species within clades share similar numbers of glands) or for natural selection (i.e., their adaptive diversification results in deviating numbers of glands from ancestors). Using the prolific Liolaemus lizard radiation from South America (where precloacal glands vary from 0-14), we present one of the largest-scale tests of both hypotheses to date. Based on climatic and phylogenetic modelling, we show a clear role for both phylogenetic inertia and adaptation underlying gland variation: (i) solar radiation, net primary productivity, topographic heterogeneity and precipitation range have a significant effect on number of PG variation, (ii) humid and cold environments tend to concentrate species with a higher number of glands, (iii) there is a strong phylogenetic signal that tends to conserve the number of PG within clades. Collectively, our study confirms that the inertia of niche conservatism can be broken down by the need of species facing different selection regimes to adjust their glands to suit the demands of their specific environments

Los escorpiones: aspectos ecológicos, biológicos y toxinológicos

ResumenLos escorpiones son artrópodos quelicerados distribuidos en las regiones tropicales y subtropicales del mundo. Su veneno es una mezcla bioquímica compleja, formada principalmente por proteinas neurotóxicas de bajo peso molecular que ejercen su acción sobre los canales iónicos, ocasionando efectos nocivos en sus victimas.Palabras clave: Escorpiones, toxínas, canales iónicos

Revision of the New World species of the genus Pelecorhynchus Macquart, 1850 (Diptera: Pelecorhynchidae)

Llanos, Lorena, Gonzalez, Christian R., Córdoba, Mónica Saldarriaga (2015): Revision of the New World species of the genus Pelecorhynchus Macquart, 1850 (Diptera: Pelecorhynchidae). Zootaxa 3955 (2): 188-210, DOI: http://dx.doi.org/10.11646/zootaxa.3955.2.

Phenotypic differences in a cryptic predator: Factors influencing morphological variation in the terciopelo Bothrops asper (Garman, 1884; Serpentes: Viperidae)

The terciopelo Bothrops asper, is a cryptic lancehead pitviper widely distributed in humid environments of Middle America and the north-western portion of South America. Throughout its extensive distribution range, the terciopelo exhibits great morphological variation in external characters, a situation that has complicated its proper separation from other related species. In this paper, we analyzed the phenotypic variation of B. asper based in a sample of 514 specimens from nine distinct physiographic regions. Univariate and multivariate analyses demonstrated great phenotypic differentiation among most pre-established groups, and the pattern is fairly congruent between sexes. However, no correspondence was observed between morphological variation and molecular divergence, inferred from mDNA sequences, between individuals representing the physiographical regions under study. Geographic variation in the number of interrictals, ventral scales, subcaudal scales and dorsal blotches was po

Primary structures and partial toxicological characterization of two phospholipases A2 from Micrurus mipartitus and Micrurus dumerilii coral snake venoms

Snake venom phospholipases A2 (PLA2) share high sequence identities and a conserved structural scaffold, but show important functional differences. Only a few PLA2s have been purified and characterized from coral snake (Micrurus spp.) venoms, and their role in envenomation remains largely unknown. In this report, we describe the isolation, sequencing and partial functional characterization of two Micrurus PLA2s: MmipPLA2 from Micrurus mipartitus and MdumPLA2 from Micrurus dumerilii, two species of clinical importance in Colombia. MmipPLA2 consisted of 119 amino acid residues with a predicted pI of 8.4, whereas MdumPLA2 consisted of 117 residues with a pI of 5.6. Both PLA2s showed the conserved 'group I' cysteine pattern and were enzymatically active, although MdumPLA2 had higher activity. The two enzymes differed notably in their toxicity, with MmipPLA2 being highly lethal to mice and mildly myotoxic, whereas MdumPLA2 was not lethal (up to 3 μg/g body weight) but strongly myotoxic. MdumPLA2 displayed higher anticoagulant activity than MmipPLA2 in vitro and caused more sustained edema in the mouse footpad assay. Neither of these enzymes was cytolytic to cultured skeletal muscle C2C12 myotubes. Based on their structural differences, the two enzymes were placed in separate lineages in a partial phylogeny of Micrurus venom PLA2s and this classification agreed with their divergent biological activities. Overall, these findings highlight the structural and functional diversity of Micrurus venom PLA2s.Universidad de Costa Rica/[741-B3-760]/UCR/Costa RicaUniversidad de Antioquia/[111556933661]/UdeA/ColombiaUniversidad de Antioquia/[617]/UdeA/ColombiaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Venom from Opisthacanthus elatus scorpion of Colombia, could bemore hemolytic and less neurotoxic than thought

We report the first biochemical, biological, pharmacological and partial proteomic characterizationstudies of the Opisthancanthus elatus venom (Gervais, 1844) from Colombia.We report the first biochemical, biological, pharmacological and partial proteomic characterizationstudies of the Opisthancanthus elatus venom (Gervais, 1844) from Colombia. The Reverse Phase High-Performance Liquid Chromatography venom profile showed 28 main well-defined peaks, most elutingbetween 20 and 45 min (18–30% of acetonitrile, respectively). High-resolution mass analysis indicatesthe presence of 106 components ranging from 806.59742 Da to 16849.4139 Da. O. elatus venom showedhemolytic activity and hydrolyzed the specific substrate BapNa suggesting the presence of proteins withserine-protease activity. Collected RP-HPLC fractions eluting at 52.6, 55.5, 55.8, 56.2, and 63.9 min (PLA2region between 33 and 40% of acetonitrile), showed hemolytic activity and hydrolyzed the synthetic sub-strate 4-nitro-3-octanoyloxy-benzoic acid, indicating the presence of compounds with phospholipasesA2activity. These RP-HPLC fractions, showed molecular masses values up to 13978.19546 Da, corroborat-ing the possible presence of the mentioned enzymes. Tryptic digestion and MS/MS analysis showed thepresence of a phospholipase like fragment, similar to on described in other Opisthacanthus genus studies.No coagulant activity was observed. No larvicidal or antimicrobial activity was observed at concentra-tions evaluated. Lethal and toxic activity is expected at doses above 100 mg/kg, no neurotoxic effects weredetected at lower doses. In conclusion, O. elatus exhibits a venom with a predominant phospholipase A2activity than thought; mammal’s neurotoxic activity is expected above the 100 mg/kg, which is very highcompared to the venom from other neurotoxic scorpions

MS/MS analysis of four scorpion venoms from Colombia: a descriptive approach

Background: Scorpions are widely known for the neurotoxic effects of their venoms, which contain peptides affecting ionic channels. Although Colombia is recognized for its scorpion diversity, only a few studies are available describing the venom content. Methods: In this descriptive study, we analyzed the MS/MS sequence, electrophoretic and chromatographic profile linked to a bioinformatics analysis of the scorpions Chactas reticulatus (Chactidae), Opisthacanthus elatus (Hormuridae), Centruroides edwardsii (Buthidae) and Tityus asthenes (Buthidae) from Colombia. Results: Each scorpion showed a specific electrophoretic and chromatographic profile. The electrophoretic profiles indicate the presence of high molecular mass compounds in all venoms, with a predominance of low molecular mass compounds in the Buthidae species. Chromatographic profiles showed a similar pattern as the electrophoretic profiles. From the MS/MS analysis of the chromatographic collected fractions, we obtained internal peptide sequences corresponding to proteins reported in scorpions from the respective family of the analyzed samples. Some of these proteins correspond to neurotoxins affecting ionic channels, antimicrobial peptides and metalloproteinaselike fragments. In the venom of Tityus asthenes, the MSn analysis allowed the detection of two toxins affecting sodium channels covering 50% and 84% of the sequence respectively, showing 100% sequence similarity. Two sequences from Tityus asthenes showed sequence similarity with a phospholipase from Opisthacanthus cayaporum indicating the presence of this type of toxin in this species for the first time. One sequence matching a hypothetical secreted protein from Hottentotta judaicus was found in three of the studied venoms. We found that this protein is common in the Buthidae family whereas it has been reported in other families – such as Scorpionidae – and may be part of the evolutionary puzzle of venoms in these arachnids. Conclusion: Buthidae venoms from Colombia can be considered an important source of peptides similar to toxins affecting ionic channels. An interesting predicted antimicrobial peptide was detected in three of the analyzed venoms.https://orcid.org/0000-0003-1332-5106Infettaresebastian.estrada@[email protected]@[email protected]