741 research outputs found

    evolution, structure and function of metazoan splicing factor PRPF39

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    In the yeast U1 snRNP the Prp39/Prp42 heterodimer is essential for early steps of spliceosome assembly. In metazoans no Prp42 ortholog exists, raising the question how the heterodimer is functionally substituted. Here we present the crystal structure of murine PRPF39, which forms a homodimer. Structure-guided point mutations disrupt dimer formation and inhibit splicing, manifesting the homodimer as functional unit. PRPF39 expression is controlled by NMD-inducing alternative splicing in mice and human, suggesting a role in adapting splicing efficiency to cell type specific requirements. A phylogenetic analysis reveals coevolution of shortened U1 snRNA and the absence of Prp42, which correlates with overall splicing complexity in different fungi. While current models correlate the diversity of spliceosomal proteins with splicing complexity, our study highlights a contrary case. We find that organisms with higher splicing complexity have substituted the Prp39/Prp42 heterodimer with a PRPF39 homodimer

    Avaliação das injúrias causadas por Anastrepha fraterculus (Wied.) sobre a incidência de podridões de cachos em videira da cv. ‘Itália’ em cultivo protegido.

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    Este trabalho teve como objetivo avaliar o efeito da associação entre as injúrias causadas pela mosca-das-frutas sul-americana (MFSA) A. fraterculus com Botrytis cinerea e Glomerella cingulata na cultura da videira.Resumo

    Computation of schenberg response function by using finite element modelling

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    Schenberg is a detector of gravitational waves resonant mass type, with a central frequency of operation of 3200 Hz. Transducers located on the surface of the resonating sphere, according to a distribution half-dodecahedron, are used to monitor a strain amplitude. The development of mechanical impedance matchers that act by increasing the coupling of the transducers with the sphere is a major challenge because of the high frequency and small in size. The objective of this work is to study the Schenberg response function obtained by finite element modeling (FEM). Finnaly, the result is compared with the result of the simplified model for mass spring type system modeling verifying if that is suitable for the determination of sensitivity detector, as the conclusion the both modeling give the same results.Sao Paulo Federal Institute Rua Pedro Vicente 625, 01109-010 Sao Paulo, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilWeb of Scienc

    Interações tritróficas entre moscas-das-frutas (Diptera: Tephritidae), seus hospedeiros e parasitoides (Hymenoptera) e avaliação de atrativos para o monitoramento na Região da Serra Gaúcha, RS.

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    Dissertação (Mestrado em Fitossanidade) - Programa de Pós-Graduação em Fitossanidade, Universidade Federal de Pelotas, Pelotas. Orientado por Dr. Flávio ROberto Mello Garcia, co-orientado por Marcos Botton, CNPUV

    Técnica de criação de Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) em laboratório utilizando hospedeiro natural.

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    Uma técnica para criação de todas as fases de desenvolvimento da mosca-das-frutas sul-americana, Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae), em laboratório (T 24 ± 2°C; UR 70 ± 10% e fotofase 16 horas) utilizando dieta natural foi avaliada e descrita. Os adultos foram criados em gaiolas plásticas de polietileno transparente (41 x 29,5 x 30 cm) e alimentados com dieta artificial contendo extrato de soja, açúcar mascavo e gérmen de trigo, nas proporções de 3:1:1, além de água. Em cada gaiola, foi utilizada uma densidade média de 167 ± 25 casais. As fêmeas ovipositaram em frutos de mamão-papaia (Carica papaya L.) trocados a intervalos de 48 horas e mantidos em caixas plásticas (37 x 14 x 29 cm) com fundo coberto por vermiculita. Sobre a camada de vermiculita, foi colocada uma tela plástica de malha de 2 mm, para facilitar a retirada dos restos de mamão desidratado após o desenvolvimento larval. As larvas completaram o desenvolvimento no mamão passando à fase de pupa após 15 ± 2 dias. Em cada mamão (401 ± 16 gramas), foram coletadas 168 ± 27 pupas, obtendo-se 385 ± 44 pupas (viabilidade de 95 ± 2%) por semana, com peso médio de 1,33 ± 0,05 gramas a cada 100 pupas. Os insetos obtidos podem ser destinados a condução de bioensaios ou na manutenção da criação. A metodologia descrita permite o desenvolvimento de uma geração (ovo-adulto) a cada 32 ± 2 dias, perfazendo aproximadamente 11 gerações/ano.bitstream/item/31529/1/bop015.pd

    Classificação de cultivares de brássicas com relação à resistência à traça-das-crucíferas e à presença de glucosinolatos.

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    O objetivo deste trabalho foi avaliar o efeito de cultivares de repolho e de couve na biologia da traça-das-crucíferas; analisar a composição química das plantas, em relação aos glucosinolatos e aplicar a análise multivariada na classificação das cultivares. Foram utilizadas as cultivares: de repolho verde Chato-de-quintal e o híbrido Midori; de repolho roxo Roxo precoce e o híbrido Roxo TPC00682; e de couve-manteiga Geórgia (padrão de suscetibilidade) e Geórgia híbrido HS20. Foram avaliadas as características biológicas da praga: viabilidade e duração das fases larval e pupal, razão sexual, fecundidade das fêmeas, longevidade dos adultos e duração e viabilidade da fase de ovo, tendo-se calculado o potencial reprodutivo corrigido (PRC). Obtiveram-se as correlações entre os parâmetros pelo método de Pearson, e realizaram-se análises multivariadas de agrupamento e de componentes principais. Em cromatógrafo líquido, avaliaram-se a presença de sinigrina e de outros glucosinolatos nas plantas. A cultivar Geórgia e os híbridos HS20 e Roxo foram classificados como altamente suscetíveis; 'Roxo precoce' e 'Midori' como suscetíveis e, 'Chato-de-quintal' como moderadamente resistente à Plutella xylostella. As análises multivariadas proporcionam melhor classificação das cultivares, em razão do grau de resistência apresentado. Os materiais genéticos avaliados não apresentam a substância secundária sinigrina

    Invasive Crayfish moving Northwards: management challenges and policy implications at the local scale

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    Freshwater ecosystems in Italy, as most European countries, have been severely impacted by the invasion of alien crayfish. The two most widespread species in Trentino (NE Italy) are Procambarus clarkii and Faxionus limosus; for both species, the high elevation and cold climate of most of the Trentino territory represent a climatic barrier to their northwards spread. Procambarus clarkii is present in one small lake at 950 m asl, and Faxionus limosus in a group of 5 lakes at 450 m asl, over an area of about 80km2. the introduction of both species is associated with fish restocking, and lead to the extinction of existing populations of the native stone crayfish Austropotamobius pallipes. The Management Plan of Austropotamobius pallipes in Trentino listed the eradication/containment of these IAS populations among the conservation priorities for the native populations. The eradication campaigns of P. clarkii started in 2018 with a release/recapture campaign aimed at assessing the abundance of the populations, and continued in 2020, 2021, 2022. As a result, the capture efficiency decreased, suggesting a population reduction trend. The containment of Faxionus limosus is more difficult, given its presence in a higher number of lakes, three of which are hydrologically connected. A first containment campaign to prevent its spread in the river network is planned for summer 2023. The financial support to these activities has been granted by the local Nature 2000 networks and by the local administrations, which have also promoted the communication with citizens and stakeholders to raise consensus and collaboratio

    Life-History and Behavior of the Diamondback Moth Plutella xylostella on Brassicaceae Cultivars over Multiple Generations

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    The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a cosmopolitan pest that causes leaf-area reduction in Brassicaceae plants. DBM populations have significant genetic variability that manifests in different feeding preferences and reproductive behaviors across generations. We evaluated the influence of Brassicaceae cultivars on biological and behavioral parameters across 18 generations of DBM populations that were separated and held on three varieties of Brassicaceae: Brassica oleracea var. acephala (kale), Brassica oleracea var. italica (broccoli), and Brassica oleracea var. capitata (cabbage). P, F6, F12, and F18 generations were evaluated, and biological aspects of young adulthood and fertility parameters of adults held on each host plant were examined over multiple generations. Additionally, larvae and adults were subjected to dual-choice and multiple-choice (feeding and oviposition) between cultivars, over generations. The results indicated that larvae of P. xylostella consumed greater quantities of kale and broccoli cultivars, on average (4.05 cm2), than cabbage (2.7 cm2). The number of eggs per female in F18 generation was 1.95 and 2.17 times higher than those in the parental (P) generation, when reared on kale and cabbage. The population reared exclusively on kale had higher net population growth rate (R0), intrinsic rate (rm), finite rate (λ) and generation time (T) than that reared on broccoli and cabbage. Last generations evaluated, the larval stage reared on cabbage showed feeding preference (F18) and oviposition preference (F12 and F18) for cabbage. Thus, we note the existence of learning, characterized as pre-imaginal conditioning to cabbage cultivars, over various DBM generations

    Host plant effects on the development, survival, and reproduction of dysmicoccus brevipes (Hemiptera: Pseudococcidae) on grapevines.

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    Dysmicoccus brevipes (Cockerell, 1893) (Hemiptera: Pseudococcidae) is one of the most frequent and abundant mealybugs in Brazilian vineyards, where it causes direct and indirect damage to the vines. In this study, we investigated the effect of plant structures, cultivars, and vine rootstocks on the development, survival, and reproduction of D. brevipes under laboratory conditions. Leaves of the tablegrape cultivar ÔIta´liaÕ (Vitis vinifera) and ÔNia´gara RosadaÕ (Vitis labrusca) and the vine roots of the rootstocks Paulsen 1103 (Vitis berlandieriV. rupestris) and IAC 572 (Vitis caribaea101-14 Mgt) were used as host plants. D. brevipes developed on different vegetative structures, cultivars, and vine rootstocks. D. brevipes showed the shortest developmental period and highest survival and fecundity rates on leaves of cultivar Ita´lia. Survival on leaves was signiÞcantly higher than on roots. Roots of IAC 572 were unsuitable for D. brevipes development, resulting in nonreproductive females.ThemealybugsÕ longevityonleaves and vine roots was similar. Higher intrinsic and Þnite rates of increase and net reproductive rate were observed whenmealybugs developed on Ita´lia leaves.Weconcluded that the host plant affects the development and survival of D. brevipes and that the choice of the most appropriate cultivar or vine rootstock can help to reduce pest infestation, and is therefore an additional component to be included in the integrated pest management of grapes
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