Unable to write in log file ../../bases/logs/portalorg/logerror.txt Pesquisa | Portal Regional da BVS
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Mais filtros

Intervalo de ano de publicação
Commun Biol ; 5(1): 104, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115634


Over the last half of the 20th century, the western Antarctic Peninsula has been one of the most rapidly warming regions on Earth, leading to substantial reductions in regional sea ice coverage. These changes are modulated by atmospheric forcing, including the Amundsen Sea Low (ASL) pressure system. We utilized a novel 25-year (1993-2017) time series to model the effects of environmental variability on larvae of a keystone species, the Antarctic Silverfish (Pleuragramma antarctica). Antarctic Silverfish use sea ice as spawning habitat and are important prey for penguins and other predators. We show that warmer sea surface temperature and decreased sea ice are associated with reduced larval abundance. Variability in the ASL modulates both sea surface temperature and sea ice; a strong ASL is associated with reduced larvae. These findings support a narrow sea ice and temperature tolerance for adult and larval fish. Further regional warming predicted to occur during the 21st century could displace populations of Antarctic Silverfish, altering this pelagic ecosystem.

Distribuição Animal , Mudança Climática , Ecossistema , Lepisma/fisiologia , Temperatura , Animais , Regiões Antárticas
PLoS One ; 16(11): e0260536, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34843543


The long-tailed silverfish Ctenolepisma longicaudatum (Lepismatidae: Zygentoma) is a nuisance problem in buildings and a major concern in museums, libraries and archives where it cause damage to historical and priceless items. We used laboratory bioassays and two field studies of infested buildings to evaluate spatial and temporal elements of a poisoned bait strategy. In both laboratory experiments and field studies, the efficiency of poisoned bait with indoxacarb as the active ingredient was significantly improved by placing many small bait droplets evenly distributed along all edges of the treated area compared to more clustered distributions. Extended duration of bait presence and removal of competing food sources improved the control effect significantly in the laboratory bioassays. Bait-treated populations also showed a significant decline in the number of eggs deposited and emergence of new nymphs. The study supports poisoned bait as an efficient and low risk approach against the long-tailed silverfish in which extended duration of bait presence, wide distribution of bait droplets in combination with sanitation was crucial for control in the infested premises.

Controle de Insetos/métodos , Lepisma/fisiologia , Animais , Feminino , Controle de Insetos/instrumentação , Inseticidas/toxicidade , Bibliotecas , Masculino , Museus , Oxazinas/toxicidade
Peptides ; 144: 170610, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34242680


Only few genes are known from insects that encode multiple neuropeptides, i.e., peptides that activate different receptors. Among those are the capa and pk genes, which differentiated within Hexapoda following gene duplication. In our study, we focus on the early stages of differentiation of these genes. Specifically: (1) What was the expression pattern of the ancestral capa/pk gene, i.e., prior to gene duplication? (2) What is the expression pattern of capa and pk in silverfish, whose ancestors diverged from Pterygota more than 400 mya? Our results suggest the location and projection of CAPA immunoreactive Va cells in abdominal ganglia (trunk ganglia in Remipedia) are a plesiomorphic trait that was already present in the ancestor of Remipedia and Hexapoda. General features of serial homology such as location of cells bodies, contralateral projection of primary neurites, and presumed peripheral peptide release from segmentally arranged neurohemal release sites could be observed in Remipedia and silverfish, but also in all Pterygota studied so far. Differences are mainly in the specific location of these peripheral release sites. This hypothetical basic pattern of capa/pk neurons underwent modifications in the anterior ganglia of the ventral nerve cord already in Remipedia. In silverfish, as in all Pterygota studied so far, pk expression in the CNS is apparently restricted to the gnathal ganglia, whereas capa expression is typical of abdominal Va cells. Thus, differentiation in the expression pattern of capa and pk genes occurred early in the evolution of Hexapoda; likely soon after the appearance of two separate genes.

Crustáceos/genética , Proteínas de Peixes/genética , Lepisma/genética , Neuropeptídeos/genética , Animais , Evolução Molecular , Proteínas de Peixes/metabolismo , Gânglios dos Invertebrados/fisiologia , Duplicação Gênica , Expressão Gênica , Proteínas de Insetos/genética , Neuropeptídeos/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
Nat Commun ; 11(1): 1509, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32198346


Nonsense mutations cause about 10% of genetic disease cases, and no treatments are available. Nonsense mutations can be corrected by molecules with nonsense mutation readthrough activity. An extract of the mushroom Lepista inversa has recently shown high-efficiency correction of UGA and UAA nonsense mutations. One active constituent of this extract is 2,6-diaminopurine (DAP). In Calu-6 cancer cells, in which TP53 gene has a UGA nonsense mutation, DAP treatment increases p53 level. It also decreases the growth of tumors arising from Calu-6 cells injected into immunodeficient nude mice. DAP acts by interfering with the activity of a tRNA-specific 2'-O-methyltransferase (FTSJ1) responsible for cytosine 34 modification in tRNATrp. Low-toxicity and high-efficiency UGA nonsense mutation correction make DAP a good candidate for the development of treatments for genetic diseases caused by nonsense mutations.

2-Aminopurina/análogos & derivados , 2-Aminopurina/farmacologia , Códon sem Sentido/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Mutação/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes p53/genética , Células HEK293 , Células HeLa , Humanos , Lepisma/química , Camundongos , Camundongos Nus , RNA de Transferência/genética , tRNA Metiltransferases/metabolismo
PLoS One ; 14(2): e0212505, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30817757


The digestive system of selected phytophagous insects has been examined as a potential prospecting resource for identification of novel cellulolytic enzymes with potential industrial applications. In contrast to other model species, however, limited detailed information is available that characterizes cellulolytic activity and systems in basal hexapod groups. As part of a screening effort to identify insects with highly active cellulolytic systems, we have for the first time, identified species of Zygentoma that displayed the highest relative cellulase activity levels when compared to all other tested insect groups under the experimental conditions, including model species for cellulolytic systems such as termite and cockroach species in Rhinotermitidae (formerly Isoptera) and Cryptocercidae (formerly Blattodea). The goal of the present study was to provide a morphohistological characterization of cellulose digestion and to identify highly active cellulase enzymes present in digestive fluids of Zygentoma species. Morphohistological characterization supported no relevant differences in the digestive system of firebrat (Thermobia domestica) and the gray silverfish (Ctenolepisma longicaudata). Quantitative and qualitative cellulase assays identified the foregut as the region with the highest levels of cellulase activity in both T. domestica and C. longicaudata. However, T. domestica was found to have higher endoglucanase, xylanase and pectinase activities compared to C. longicaudata. Using nano liquid chromatography coupled to tandem mass spectrometry (nanoLC/MS/MS) and a custom gut transcriptome we identified cellulolytic enzymes from digestive fluids of T. domestica. Among the identified enzymes we report putative endoglucanases matching to insect or arthropod enzymes and glucan endo-1,6-ß-glucosidases matching bacterial enzymes. These findings support combined activities of endogenous and symbiont-derived plant cell wall degrading enzymes in lignocellulose digestion in Zygentoma and advance our understanding of cellulose digestion in a primitive insect group.

Celulase/metabolismo , Proteínas de Insetos/metabolismo , Insetos/enzimologia , Animais , Celulase/genética , Baratas/enzimologia , Baratas/genética , Baratas/microbiologia , Sistema Digestório/anatomia & histologia , Sistema Digestório/enzimologia , Sistema Digestório/microbiologia , Endo-1,4-beta-Xilanases/metabolismo , Proteínas de Insetos/genética , Insetos/genética , Insetos/microbiologia , Isópteros/enzimologia , Isópteros/genética , Isópteros/microbiologia , Lepisma/enzimologia , Lepisma/genética , Lepisma/microbiologia , Modelos Biológicos , Poligalacturonase/metabolismo , Especificidade da Espécie , Transcriptoma
Sci Rep ; 8(1): 17856, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552350


The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and genetic structuring using clustering methods, F-statistics, and hierarchical analysis of variance. A lack of differentiation was found between locations connected by the Antarctic Slope Front Current (ASF), indicative of high levels of gene flow. However, gene flow was significantly reduced at the South Orkney Islands and the western Antarctic Peninsula where the ASF is absent. This pattern of gene flow emphasized the relevance of large-scale circulation as a mechanism for circumpolar connectivity. Chaotic genetic patchiness characterized population structure over time, with varying patterns of differentiation observed between years, accompanied by heterogeneous standard length distributions. The present study supports a more nuanced version of the genetic panmixia hypothesis that reflects physical-biological interactions over the life history.

Fluxo Gênico , Genética Populacional , Genótipo , Lepisma/genética , Animais , Regiões Antárticas , Análise por Conglomerados , Técnicas de Genotipagem , Repetições de Microssatélites
Zootaxa ; 4504(3): 447-450, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30486022


With the discovery of Ctenolepisma longicaudata by Goddard et al. (2016) and the record of Ctenolepisma lineata as a possible introduced pest by Notton (2018), as well as the changes to the higher classification reported by Barnard (2011), the current number of UK Lepismatidae (silverfish and firebrats) that an entomologist might encounter has doubled. Therefore, the most recent checklist (Kloet Hicks 1964) is in need of revision. This paper aims to provide an updated check list, guide to keys that can be used to Identify UK Lepismatidae as well as to provide an overview of UK species.

Insetos , Lepisma , Animais , Reino Unido
Carbohydr Polym ; 197: 540-547, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30007645


The present study examined the role of a polysaccharide (LSP, 25 and 100 µg/ml) from the fruiting bodies of Lepista sordid on the immunosuppressive enzyme indoleamine 2, 3-dioxygenase (IDO) in HepG2 cells, and the possible mechanism of action. IDO expression and kynurenine production from LSP-treated HepG2 cells following IFN-γ stimulation were dramatically inhibited by LSP treatment. In line with this, the medium of HepG2 cells pretreated with LSP improved the survival rate of primary CD4+ and CD8+ T cells as compared with IFN-γ-treated control cells. Moreover, tyrosine 701 and serine 727 phosphorylation of STAT1 were dramatically reduced by LSP pretreatment in IFN-γ-stimulated HepG2 cells. Furthermore phosphorylation of JAK-1 and JAK-2 was also inhibited by LSP. Additionally, two IDO promoters (GAS and ISRE) were inhibited in cells pretreated with LSP prior to IFN-γ exposure. These findings suggest that LSP exerts antitumor effects on HepG2 cells by inhibiting IDO via JAK-PKC-δ-STAT1 signaling pathway.

Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Janus Quinase 1/antagonistas & inibidores , Polissacarídeos/farmacologia , Proteína Quinase C-delta/antagonistas & inibidores , Fator de Transcrição STAT1/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Carpóforos/química , Células Hep G2 , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Janus Quinase 1/metabolismo , Lepisma/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Proteína Quinase C-delta/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
Arq. Inst. Biol ; 81(2): 140-144, abr.-jun. 2014. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1004998


A traça Tuta absoluta (Meyrick) é o inseto-praga que mais compromete a produção do tomateiro. Basear o seu controle no uso de inseticidas sintéticos pode comprometer a cultura em termos econômicos e ambientais. Como alternativa de controle, o óleo de nim foi aplicado em folhas de tomateiro, avaliando os efeitos inseticida e antialimentar por ação sistêmica e translaminar. No ensaio para avaliar a ação translaminar, o óleo diluído em água foi aplicado na superfície adaxial dos folíolos, em concentrações de 0,5, 1, 5 e 10%. A mortalidade observada variou entre 49 e 100%, e o tamanho médio das minas, entre 1,62 e 0,34 cm. Nos tratamentos representados por água e água + emulsificante (5%), a mortalidade não ultrapassou 20%, com tamanho médio das minas de 1,63 cm. O estudo da ação sistêmica foi realizado ao aplicar o óleo de nim na superfície adaxial e abaxial de todas as folhas das plantas, à exceção daquelas em que as lagartas foram infestadas. Neste ensaio, o óleo foi aplicado nas concentrações de 1, 2,5 e 5%, diluídos em água e emulsificante. Observou-se que a mortalidade foi maior que 90% quando o óleo foi aplicado nas concentrações de 2,5 e 5%, sendo o tamanho médio das minas inferior a 1,0 cm. Não ocorreu mortalidade nos tratamentos controle, mas o tamanho das minas foi, em média, de 1,96 cm. Desta maneira ficou evidenciado que o óleo de nim apresenta efeito inseticida e antialimentar sobre lagartas de T. absoluta, com a propriedade de ser incorporado e translocado através das folhas de tomateiro.(AU)

The leaf miner Tuta absoluta (Meyrick) is the pest that mostly jeopardizes tomato production. The use of synthetic pesticides for its control can affect the crop economically and environmentally. As an alternative form of control, neem oil was applied on tomato leaves in order to assess antifeedant and insecticidal effects by systemic and translaminar action. In experiment for translaminar action, oil diluted in water was applied to the adaxial surface of leaflets at concentrations of 0.5, 1, 5 and 10%. The mortality rate ranged between 49 and 100%, and the average size of the mines, between 1.62 and 0.34 cm. In treatments represented by water and water + emulsifier (5%), mortality did not surpass 20%, with the average size of mines reaching 1.63 cm. The study of systemic action was performed by applying neem oil to the adaxial and abaxial surfaces of all leaves, except those that were infested by caterpillars. In this assay, the oil was applied at concentrations of 1, 2.5 and 5%, being diluted in water and emulsifiers. We observed that the mortality rate exceeded 90% when the oil was applied at concentrations of 2.5 and 5%, and the average size of mines was smaller than 1.0 cm. There was no mortality in the control treatments, but the mine size was on average 1.96 cm. Therefore, it is clear that the neem oil has an insecticidal and anti-food effect on T. absoluta caterpillars, and is possible to be incorporated and applied on tomato leaves.(AU)

Solanum lycopersicum , Azadirachta , Lepisma , Inseticidas , Controle de Pragas , Insetos