261 research outputs found

    Association of mitochondrial lysyl-tRNA synthetase with HIV-1 GagPol involves catalytic domain of the synthetase and transframe and integrase domains of Pol

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    Aim. Analyze the interaction between Lysyl-tRNA synthetase (LysRS) and HIV-1 GagPol to know whether a particular N-terminal sequence of mitochondrial LysRS triggers a specific recognition with GagPol. Methods. Yeast two-hybrid analysis, immunoprecipitation. Results. We have shown that LysRS associates with the Pol domain of GagPol. Conclusions. A model of the assembly of the LysRS:tRNA₃Lys:GagPol packaging complex is proposed. Keywords: tRNA₃Lys, lysyl-tRNA synthetase, HIV-1, packaging.Мета. Встановити, чи може N-кінцева послідовність, яка є специфічною для мітохондріальної форми лізил-тРНК синтетази, забезпечувати взаємодію цього ферменту з білком GagPol ВІЛ-1. Методи. Двогібридна дріжджова система, імунопреципітація. Результати. Ми показали що лізил-тРНК синтетаза взаємодіє з доменом Pol білка Gag. Висновки. Запропоновано модель утворення комплексу ЛізРС:тРНК₃Ліз:GagPol. Ключові слова: тРНК₃Ліз, лізил-тРНК синтетаза, ВІЛ-1, збирання віріона.Цель. Выяснить, может ли N-концевая последовательность, являющаяся специфичной для митохондриальной формы лизилтРНК синтетазы, обеспечивать взаимодействие этого фермента с белком GagPol ВИЧ-1. Методы. Двугибридная дрожжевая система, иммунопреципитация Результаты. Мы показали, что лизил-тРНК синтетаза взаимодействует с доменом Pol белка Gag. Выводы. Предложена модель образования комплекса ЛизРС:тРНК₃Лиз:GagPol. Ключевые слова: тРНК₃Лиз, лизил-тРНК синтетаза, ВИЧ-1, сборка вириона

    COMPUTER SIMULATIONS OF POSSIBLE FUTURES FOR TWO FLOCKS OF WHOOPING CRANES

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    We conducted computer simulations using the program VORTEX (version 7) to project population sizes, growth rates, genetic diversity, and probabilities of extinction over the next 100 years for 2 flocks of whooping cranes (Grus americana), the Aransas/Wood Buffalo population and the experimental Florida population. Standard runs based on best estimates of demographic. genetic, and environmental parameter values were used as a baseline to which several alternative scenarios were compared. Results generally supported the conclusion of the earlier Population Viability Assessment (Mirande et al. 1991) that the AransaslWood Buffalo population will continue to grow steadily with less than a 1 % probability of extinction. It was noted, however, that a combination of negative factors such as shrinking habitat and increased probabilities of catastrophes accompanied by increased mortality rates could put this population at risk. Results for the Florida population were less optimistic. The standard run produced a population growth rate (r) of only 0.0026 for the next 100 years, and this shifted down to -0.0001 over a 200-year time frame. Adult mortality in this flock would have to be about 20% lower than the predicted value (10%) in order to raise growth rates to above r = 0.02. Amount and duration of supplementation of the Florida flock had minimal impacts on the long-tenn growth rate of the flock. It is the enduring rates of mortality, breeding, and disease risk that will have major effects on this population. For example, if disease risks tum out to be greater than the best-estimate scenario, this population could face a relatively high risk of extinction (17%). The formula for success in Florida is lower adult mortality, lower age of first breeding, lower disease risk, and higher productivity than the best-guess estimates. Fortunately, there are some potential management interventions (e.g., predator control, vaccines and health monitoring, selective introductions to balance the sex ratio of the flock) that may be able to push the odds in favor of success

    Molecular phylogeny of the subfamily Stevardiinae Gill, 1858 (Characiformes: Characidae): classification and the evolution of reproductive traits

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    Abstract Background The subfamily Stevardiinae is a diverse and widely distributed clade of freshwater fishes from South and Central America, commonly known as “tetras” (Characidae). The group was named “clade A” when first proposed as a monophyletic unit of Characidae and later designated as a subfamily. Stevardiinae includes 48 genera and around 310 valid species with many species presenting inseminating reproductive strategy. No global hypothesis of relationships is available for this group and currently many genera are listed as incertae sedis or are suspected to be non-monophyletic. Results We present a molecular phylogeny with the largest number of stevardiine species analyzed so far, including 355 samples representing 153 putative species distributed in 32 genera, to test the group’s monophyly and internal relationships. The phylogeny was inferred using DNA sequence data from seven gene fragments (mtDNA: 12S, 16S and COI; nuclear: RAG1, RAG2, MYH6 and PTR). The results support the Stevardiinae as a monophyletic group and a detailed hypothesis of the internal relationships for this subfamily. Conclusions A revised classification based on the molecular phylogeny is proposed that includes seven tribes and also defines monophyletic genera, including a resurrected genus Eretmobrycon, and new definitions for Diapoma, Hemibrycon, Bryconamericus sensu stricto, and Knodus sensu stricto, placing some small genera as junior synonyms. Inseminating species are distributed in several clades suggesting that reproductive strategy is evolutionarily labile in this group of fishes.http://deepblue.lib.umich.edu/bitstream/2027.42/134621/1/12862_2015_Article_403.pd

    A new species of Bryconops (Teleostei: Characidae) from the rio Madeira basin, Northern Brazil

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    Uma nova espécie de Bryconops é descrita para um tributário do rio Madeira na bacia do rio Amazonas, Brasil. Bryconops piracolina pertence ao subgênero Bryconops por não possuir dentes ou raramente apresentar apenas um dente na maxila, e por possuir uma área nua na face entre o segundo e terceiro infraorbitais. A espécie nova se distingue de todas as espécies do subgênero Bryconops pela presença de uma grande mancha negra na base da nadadeira dorsal. Além disto, difere de todas as espécies do gênero, exceto B. inpai, por possuir a nadadeira adiposa inteiramente preta. Difere de B. inpai pela ausência de manchas umerais. Difere de todas as espécies de Bryconops, exceto B. caudomaculatus, por possuir as últimas escamas da série longitudinal de escamas da linha lateral sem poros além da terminação da placa hipural e difere de B. caudomaculatus pelo menor número de escamas com poros da linha lateral (31-36, média 34,6 vs. 37-43 média, 40,6; respectivamente).A new species of Bryconops is described from a tributary to the rio Madeira in the Amazon basin, State of Rondônia, Brazil. Bryconops piracolina belongs to the subgenus Bryconops by having no teeth or rarely one tooth in the maxilla, and a naked area on cheek between the second and third infraorbitals. The new species is distinguished from all species of this subgenus by the presence of a large black blotch on dorsal-fin base. Furthermore, it is distinguished from all congeners, except B. inpai, by possessing the adipose fin entirely black. It differs from B. inpai by the lack of humeral spots. It further differs from all species of the subgenus Bryconops, except B. caudomaculatus, by having the last scales of the longitudinal series of scales that bears the lateral line series not pored beyond the end of the hypural plate, and differs from B. caudomaculatus by the smaller number of pored lateral line scales (31-36, mean 34.6, vs. 37-43, mean = 40.6, respectively)

    A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species

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    As espécies de Hemibrycon que ocorrem a leste das Cordilheiras dos Andes são revisadas com base na análise do material tipo e exemplares adicionais. Nove espécies são redescritas: H. beni da bacia do río Beni, Bolívia; H. helleri do alto río Ucayali, Peru; H. huambonicus para as bacias dos ríos Huallaga e Marañon, Peru; H. jeslkii para as porções superiores das bacias dos rios Marañon, Ucayali e Madeira, Bolívia, Brasil e Peru; H. metae para a bacia do río Orinoco, Colômbia e Venezuela, e bacias costeiras do Caribe na Venezuela; H. polyodon (espécie-tipo) para a bacia do río Pastaza, Equador; H. surinamensis para as bacia costeiras da Guiana Francesa e Suriname, e porção inferior das bacias dos rios Tapajós, Tocantins e Xingu, Brasil; H. taeniurus para os rios da ilha de Trinidad, Trinidad and Tobago; H. tridens para a bacia do alto río Ucayali, Peru. Duas espécies novas são descritas: H. inambari para a bacia do alto río Madre de Dios, Peru e H. mikrostiktos para a bacia do río Ucayali, Peru. Estas espécies distinguem-se principalmente pelo padrão de colorido e caracteres merísticos. A área de distribuição do gênero é ampliada para as porções inferiores das bacias do Tapajós, Tocantins e Xingu, Brasil, com o primeiro registro de H. surinamensis para este país. Uma nova diagnose e descrição são fornecidas para a espécie-tipo do gênero, apesar de ter sido recentemente redescrita. A série-tipo de H. helleri previamente considerada questionável é encontrada e descrita. Hemibrycon coxeyi e H. pautensis são considerados sinônimos juniores de H. polyodon. Tetragonopterus (Hemibrycon) trinitatis, anteriormente considerada como species inquirenda em Characidae, e Hemibrycon guppyi são sinônimos juniores de H. taeniurus. Hemibrycon orcesi é transferida para Boehlkea. É apresentada uma chave taxonômica para as espécies do gênero a leste das Cordilheiras dos Andes.The species of Hemibrycon occurring in the east of the Andean Cordilleras are reviewed based on their type series and additional specimens. Nine species are redescribed: H. beni from río Beni basin, Bolivia; H. helleri from the upper rio Ucayali, Peru; H. huambonicus from the ríos Huallaga and Marañon basins, Peru; H. jeslkii from the upper portions of ríos Marañon, Ucayali and Madeira basins, Bolivia, Brazil, and Peru; H. metae from río Orinoco basin, Colombia and Venezuela, and Caribbean coastal basins of Venezuela; H. polyodon (type species) from río Pastaza basin, Ecuador; H. surinamensis from coastal basins of French Guiana and Suriname, and from lower rios Tapajós, Tocantins and Xingu basins, Brazil; H. taeniurus from river basins from Trinidad Island, Trinidad and Tobago, and H. tridens from upper río Ucayali basin, Peru. Two new species are described: H. inambari from the upper río Madre de Dios basin, Peru and H. mikrostiktos from río Ucayali basin, Peru. These species are distinguished among themselves mainly by the color pattern, and meristic characters. The distribution area of the genus is enlarged reaching the lower Tapajós, Tocantins and Xingu river basins, Brazil, with the first record of the occurrence of H. surinamensis in this country. A new description and diagnosis is provided for the type species of the genus, regardless its recent redescription. The type series of H. helleri that was previously considered dubious is found and described. Hemibrycon coxeyi and H. pautensis are considered junior synonyms of H. polyodon. Tetragonopterus (Hemibrycon) trinitatis, previously considered species inquirenda in Characidae, and Hemibrycon guppyi are junior synonyms of H. taeniurus. Hemibrycon orcesi is transferred to Boehlkea. A taxonomic key for the species of the genus to the east of the Andean Cordilleras is presented
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