87 research outputs found

    Scenario of the spread of the invasive species Zaprionus indianus Gupta, 1970 (Diptera, Drosophilidae) in Brazil

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    Zaprionus indianus was first recorded in Brazil in 1999 and rapidly spread throughout the country. We have obtained data on esterase loci polymorphisms (Est2 and Est3), and analyzed them, using Landscape Shape Interpolation and the Monmonier Maximum Difference Algorithm to discover how regional invasion occurred. Hence, it was apparent that Z. indianus, after first arriving in SĂŁo Paulo state, spread throughout the country, probably together with the transportation of commercial fruits by way of the two main Brazilian freeways, BR 153, to the south and the surrounding countryside, and the BR 116 along the coast and throughout the north-east

    Olfactory receptors on the maxillary palps of small ermine moth larvae: evolutionary history of benzaldehyde sensitivity

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    In lepidopterous larvae the maxillary palps contain a large portion of the sensory equipment of the insect. Yet, knowledge about the sensitivity of these cells is limited. In this paper a morphological, behavioral, and electrophysiological investigation of the maxillary palps of Yponomeuta cagnagellus (Lepidoptera: Yponomeutidae) is presented. In addition to thermoreceptors, CO2 receptors, and gustatory receptors, evidence is reported for the existence of two groups of receptor cells sensitive to plant volatiles. Cells that are mainly sensitive to (E)-2-hexenal and hexanal or to (Z)-3-hexen-1-ol and 1-hexanol were found. Interestingly, a high sensitivity for benzaldehyde was also found. This compound is not known to be present in Euonymus europaeus, the host plant of the monophagous Yponomeuta cagnagellus, but it is a prominent compound in Rosaceae, the presumed hosts of the ancestors of Y. cagnagellus. To elucidate the evolutionary history of this sensitivity, and its possible role in host shifts, feeding responses of three Yponomeuta species to benzaldehyde were investigated. The results confirm the hypothesis that the sensitivity to benzaldehyde evolved during the ancestral shift from Celastraceae to Rosaceae and can be considered an evolutionary relict, retained in the recently backshifted Celastraceae-specialist Y. cagnagellus

    Aberrant Expression of Proteins Involved in Signal Transduction and DNA Repair Pathways in Lung Cancer and Their Association with Clinical Parameters

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    Because cell signaling and cell metabolic pathways are executed through proteins, protein signatures in primary tumors are useful for identifying key nodes in signaling networks whose alteration is associated with malignancy and/or clinical outcomes. This study aimed to determine protein signatures in primary lung cancer tissues.We analyzed 126 proteins and/or protein phosphorylation sites in case-matched normal and tumor samples from 101 lung cancer patients with reverse-phase protein array (RPPA) assay. The results showed that 18 molecules were significantly different (p<0.05) by at least 30% between normal and tumor tissues. Most of those molecules play roles in cell proliferation, DNA repair, signal transduction and lipid metabolism, or function as cell surface/matrix proteins. We also validated RPPA results by Western blot and/or immunohistochemical analyses for some of those molecules. Statistical analyses showed that Ku80 levels were significantly higher in tumors of nonsmokers than in those of smokers. Cyclin B1 levels were significantly overexpressed in poorly differentiated tumors while Cox2 levels were significantly overexpressed in neuroendocrinal tumors. A high level of Stat5 is associated with favorable survival outcome for patients treated with surgery.Our results revealed that some molecules involved in DNA damage/repair, signal transductions, lipid metabolism, and cell proliferation were drastically aberrant in lung cancer tissues, and Stat5 may serve a molecular marker for prognosis of lung cancers

    Specifically Progressive Deficits of Brain Functional Marker in Amnestic Type Mild Cognitive Impairment

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    Background: Deficits of the default mode network (DMN) have been demonstrated in subjects with amnestic type mild cognitive impairment (aMCI) who have a high risk of developing Alzheimer’s disease (AD). However, no longitudinal study of this network has been reported in aMCI. Identifying links between development of DMN and aMCI progression would be of considerable value in understanding brain changes underpinning aMCI and determining risk of conversion to AD. Methodology/Principal Findings: Resting-state fMRI was acquired in aMCI subjects (n = 26) and controls (n = 18) at baseline and after approximately 20 months follow up. Independent component analysis was used to isolate the DMN in each participant. Differences in DMN between aMCI and controls were examined at baseline, and subsequent changes between baseline and follow-up were also assessed in the groups. Posterior cingulate cortex/precuneus (PCC/PCu) hyper-functional connectivity was observed at baseline in aMCI subjects, while a substantial decrement of these connections was evident at follow-up in aMCI subjects, compared to matched controls. Specifically, PCC/PCu dysfunction was positively related to the impairments of episodic memory from baseline to follow up in aMCI group. Conclusions/Significance: The patterns of longitudinal deficits of DMN may assist investigators to identify and monitor the development of aMCI

    Altered Connectivity Pattern of Hubs in Default-Mode Network with Alzheimer's Disease: An Granger Causality Modeling Approach

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    Background: Evidences from normal subjects suggest that the default-mode network (DMN) has posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC) and inferior parietal cortex (IPC) as its hubs; meanwhile, these DMN nodes are often found to be abnormally recruited in Alzheimer’s disease (AD) patients. The issues on how these hubs interact to each other, with the rest nodes of the DMN and the altered pattern of hubs with respect to AD, are still on going discussion for eventual final clarification. Principal Findings: To address these issues, we investigated the causal influences between any pair of nodes within the DMN using Granger causality analysis and graph-theoretic methods on resting-state fMRI data of 12 young subjects, 16 old normal controls and 15 AD patients respectively. We found that: (1) PCC/MPFC/IPC, especially the PCC, showed the widest and distinctive causal effects on the DMN dynamics in young group; (2) the pattern of DMN hubs was abnormal in AD patients compared to old control: MPFC and IPC had obvious causal interaction disruption with other nodes; the PCC showed outstanding performance for it was the only region having causal relation with all other nodes significantly; (3) the altered relation between hubs and other DMN nodes held potential as a noninvasive biomarker of AD. Conclusions: Our study, to the best of our knowledge, is the first to support the hub configuration of the DMN from the perspective of causal relationship, and reveal abnormal pattern of the DMN hubs in AD. Findings from young subject

    Molecular Determinants of Survival Motor Neuron (SMN) Protein Cleavage by the Calcium-Activated Protease, Calpain

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    Spinal muscular atrophy (SMA) is a leading genetic cause of childhood mortality, caused by reduced levels of survival motor neuron (SMN) protein. SMN functions as part of a large complex in the biogenesis of small nuclear ribonucleoproteins (snRNPs). It is not clear if defects in snRNP biogenesis cause SMA or if loss of some tissue-specific function causes disease. We recently demonstrated that the SMN complex localizes to the Z-discs of skeletal and cardiac muscle sarcomeres, and that SMN is a proteolytic target of calpain. Calpains are implicated in muscle and neurodegenerative disorders, although their relationship to SMA is unclear. Using mass spectrometry, we identified two adjacent calpain cleavage sites in SMN, S192 and F193. Deletion of small motifs in the region surrounding these sites inhibited cleavage. Patient-derived SMA mutations within SMN reduced calpain cleavage. SMN(D44V), reported to impair Gemin2 binding and amino-terminal SMN association, drastically inhibited cleavage, suggesting a role for these interactions in regulating calpain cleavage. Deletion of A188, a residue mutated in SMA type I (A188S), abrogated calpain cleavage, highlighting the importance of this region. Conversely, SMA mutations that interfere with self-oligomerization of SMN, Y272C and SMNΔ7, had no effect on cleavage. Removal of the recently-identified SMN degron (Δ268-294) resulted in increased calpain sensitivity, suggesting that the C-terminus of SMN is important in dictating availability of the cleavage site. Investigation into the spatial determinants of SMN cleavage revealed that endogenous calpains can cleave cytosolic, but not nuclear, SMN. Collectively, the results provide insight into a novel aspect of the post-translation regulation of SMN

    The evolution of the plastid chromosome in land plants: gene content, gene order, gene function

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    This review bridges functional and evolutionary aspects of plastid chromosome architecture in land plants and their putative ancestors. We provide an overview on the structure and composition of the plastid genome of land plants as well as the functions of its genes in an explicit phylogenetic and evolutionary context. We will discuss the architecture of land plant plastid chromosomes, including gene content and synteny across land plants. Moreover, we will explore the functions and roles of plastid encoded genes in metabolism and their evolutionary importance regarding gene retention and conservation. We suggest that the slow mode at which the plastome typically evolves is likely to be influenced by a combination of different molecular mechanisms. These include the organization of plastid genes in operons, the usually uniparental mode of plastid inheritance, the activity of highly effective repair mechanisms as well as the rarity of plastid fusion. Nevertheless, structurally rearranged plastomes can be found in several unrelated lineages (e.g. ferns, Pinaceae, multiple angiosperm families). Rearrangements and gene losses seem to correlate with an unusual mode of plastid transmission, abundance of repeats, or a heterotrophic lifestyle (parasites or myco-heterotrophs). While only a few functional gene gains and more frequent gene losses have been inferred for land plants, the plastid Ndh complex is one example of multiple independent gene losses and will be discussed in detail. Patterns of ndh-gene loss and functional analyses indicate that these losses are usually found in plant groups with a certain degree of heterotrophy, might rendering plastid encoded Ndh1 subunits dispensable

    Estudo biológico e comportamental de lagartas de Spodoptera frugiperda visando à produção de Baculovírus spodoptera

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    A utilização de bioinseticida a base de Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) possui potencial para o controle de Spodoptera frugiperda (Lepidoptera: Noctuidae), porĂ©m sua obtenção em larga escala depende da maximização da produção in vivo. Assim, alguns fatores biolĂłgicos e comportamentais devem ser estudados para aperfeiçoar a produção de SfMNPV com intuito de disponibilizar um bioinseticida eficiente, economicamente viĂĄvel e que possa ser usado no manejo de S. frugiperda nos mais diversos sistemas agrĂ­colas. Entre os fatores relacionados ao hospedeiro, a temperatura e a idade para inoculação do vĂ­rus sĂŁo de extrema importĂąncia, pois interferem diretamente no ciclo de vida e na replicação viral. O comportamento tambĂ©m deve ser avaliado, para evitar condiçÔes de criação do hospedeiro que favoreçam o canibalismo e causa prejuĂ­zo na multiplicação in vivo do SfMNPV. Assim, objetivou-se determinar a melhor condição tĂ©rmica para criar as lagartas e a idade ideal, para inocular e multiplicar o vĂ­rus no hospedeiro, bem como, verificar a ocorrĂȘncia do comportamento canibal em lagartas de S. frugiperda. Os experimentos foram conduzidos no LaboratĂłrio de Controle Microbiano de Insetos do NĂșcleo de Desenvolvimento CientĂ­fico e TecnolĂłgico em Manejo FitossanitĂĄrio de Pragas e Doenças (NUDEMAFI), localizado no Centro de CiĂȘncias AgrĂĄrias da UFES, em Alegre, EspĂ­rito Santo, Brasil. A pesquisa foi desenvolvida em duas etapas, a primeira para determinar a condição tĂ©rmica e a idade ideais para criar e inocular, respectivamente, o hospedeiro com o vĂ­rus, para multiplicação in vivo de SfMNPV. A segunda etapa foi para avaliar o comportamento canibal de lagartas da espĂ©cie S. frugiperda criadas a 22, 25 e 31°C, inoculadas com SfMNPV quando com idades de 10, 8 e 4 dias, respectivamente, e mantidas em diferentes densidades populacionais (5, 10, 25 e 50 lagartas por recipiente). A mortalidade diminuiu com o aumento da temperatura e da idade do hospedeiro nas temperaturas de 25, 28 e 31 °C. O aumento na taxa de canibalismo foi 12 diretamente proporcional Ă  densidade populacional quando as lagartas foram criadas a 22 °C, inoculadas aos 10 dias de idade e 25 ÂșC, inoculadas aos 8 dias e atingiram 63,5 e 62,5%, respectivamente na densidade populacional de 50 lagartas. Mas, quando as lagartas foram criadas a 31ÂșC e inoculadas com idade de 4 dias, a densidade populacional nĂŁo afetou o comportamento canibal, taxa mĂ©dia de 24%, inferior aos outros tratamentos com 50 lagartas por recipiente. Demonstrando que Ă© viĂĄvel para a multiplicação viral, criar lagartas a 31 °C e aos 4 dias de idade inocular o vĂ­rus, podendo a partir de entĂŁo colocar atĂ© 50 lagartas por recipiente, o que reduz a mĂŁo-de-obra necessĂĄria para individualizar as lagartas e otimiza o espaço fĂ­sico em uma biofĂĄbrica. Portanto, se para otimizar o processo produção viral e o serviço em uma biofĂĄbrica, Ă© preciso maximizar a produção viral, reduzir o tempo de multiplicação do vĂ­rus e o canibalismo entre as lagartas, com ausĂȘncia de contaminação da criação, a temperatura e idade ideais para criação massal de S. frugiperda e inoculação do vĂ­rus nas lagartas, respectivamente, visando produção de baculovĂ­rus em larga escala sĂŁo de 31 ÂșC e 4 dias

    Life history, climate and biogeography interactively affect worldwide genetic diversity of plant and animal populations.

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    Understanding how biological and environmental factors interactively shape the global distribution of plant and animal genetic diversity is fundamental to biodiversity conservation. Genetic diversity measured in local populations (GDP) is correspondingly assumed representative for population fitness and eco-evolutionary dynamics. For 8356 populations across the globe, we report that plants systematically display much lower GDP than animals, and that life history traits shape GDP patterns both directly (animal longevity and size), and indirectly by mediating core-periphery patterns (animal fecundity and plant dispersal). Particularly in some plant groups, peripheral populations can sustain similar GDP as core populations, emphasizing their potential conservation value. We further find surprisingly weak support for general latitudinal GDP trends. Finally, contemporary rather than past climate contributes to the spatial distribution of GDP, suggesting that contemporary environmental changes affect global patterns of GDP. Our findings generate new perspectives for the conservation of genetic resources at worldwide and taxonomic-wide scales
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