123 research outputs found

    Coupling in-depth genome annotations with genome editing technology for harnessing genomic variation to promote precision breeding in tropical soybean.

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    ABSTRACT: Directional selection during crop domestication and advanced breeding has resulted in significant changes in plant genomes. The extent of intraspecific variation in a crop documents domestication and highlights variants underlying complex traits. Studies demonstrate that most naturally occurring variants in crops are low frequency, and only a small fraction of those might have important functions to trait variation. To understand the inheritance of quantitative traits, diversity panels have become available by crossing inbred lines to produce genomic maps that relate phenotypic variation to recombination and ultimately to genome structure. Using these resources, genomics studies have suggested that selection performs poorly in pericentromeric regions because of reduced recombination frequency (RF). Thus, manipulating RF and meiotic crossover location is an appealing issue to advance crop breeding. In our study, we are using genomic analysis to characterize intragenomic diversity of tropical elite soybean lines in terms of heterozygosity, RF, chromatin structure and accessibility. Our results to date include the generation of draft genome assemblies for two soybean advanced lines using PACBIO long-read sequencing, Chromium Linked-Reads sequencing and an approach rooted in polymer physics that determines the most likely genome structure using chromosomal contact data. In-depth genome-wide characterization is ongoing using ATAC-Seq and Parent-Progeny resequencing. We also present our efforts to apply DNA-free editing tools in implementing genetic alterations that are expected to engineer desirable traits in soybeans by modifying meiotic specific expression. These changes are expected to increase genetic and epigenetic variations with favorable outcomes in seed oil and protein pathway regulation. Financial support: Embrapa-Monsanto Fund/Project:03.17.03.002.00.0

    Temporalidade e representações sociais: Estabilidade e dinâmica dos elementos ativados pelo regime militar brasileiro

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    The structural approach of social representations considers that a social representation is composed of cognems with different status: central and peripheral. All perspectives sustain that the representations’ phenomenon is historic and linked to temporality. It seems to us that such temporality, both synchronic and diachronic, may operate as a criterion to distinguish central from peripheral elements, since the former are more stable than the latter by definition. In this work we present a study about the representation of the Brazilian Military Regime among young people (N = 295) that employed different techniques to distinguish central and peripheral elements (basic cognitive schemes and prototypical analysis). The results of the study are compared with previous research about the same object. The comparison of the results shows that only three cognems (censorship, dictatorship and repression) keep their central status regardless of the technique and moment. As a conclusion, we discuss the pertinence of diachronic and inter‑technique comparisons to study the representational structure.A abordagem estrutural das representações sociais considera que uma representação social é composta por cognemas de diferentes status: central e periférico. Todas as abordagens consideram que o fenômeno das representações é histórico e ligado à temporalidade.Parece‑nos que esta temporalidade, tanto sincrônica quanto diacrônica, pode servir como critério para distinguir os elementos centrais dos periféricos já que os primeiros são, por definição, mais estáveis que os segundos. Neste trabalho apresentamos uma pesquisa sobrea representação do Regime Militar brasileiro entre jovens (N = 295) que utilizou diferentes técnicas para distinguir os elementos centrais dos periféricos (os esquemas cognitivos de base e análise prototípica). Os resultados desta pesquisa são comparados com as pesquisas precedentes sobre o mesmo objeto. A comparação dos resultados mostra que somente três cognemas (censura, ditadura e repressão) se mantêm como centrais independentemente da técnica e do momento, o que nos leva a discutir a pertinência de comparações diacrônicas e intertécnicas para se estudar a estrutura representacional

    Quantum Criticality in Heavy Fermion Metals

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    Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points. There have been considerable efforts, both experimental and theoretical, which use these magnetic systems to address problems that are central to the broad understanding of strongly correlated quantum matter. Here, we summarize some of the basic issues, including i) the extent to which the quantum criticality in heavy fermion metals goes beyond the standard theory of order-parameter fluctuations, ii) the nature of the Kondo effect in the quantum critical regime, iii) the non-Fermi liquid phenomena that accompany quantum criticality, and iv) the interplay between quantum criticality and unconventional superconductivity.Comment: (v2) 39 pages, 8 figures; shortened per the editorial mandate; to appear in Nature Physics. (v1) 43 pages, 8 figures; Non-technical review article, intended for general readers; the discussion part contains more specialized topic

    Depleção do quadro de leitura upstream como nova estratégia para manipular a tradução de gmpr10 usando crispr/cas9 para aumentar a tolerância da soja a fitonematoides.

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    In this study, we identified two uORFs in the 5'-UTR sequence of this gene. The entire 5' leader sequence was amplified, cloned, and site-directed mutated to delete its uORFs start codons (-ATG). The validation of these predicted uORFs was carried out in transformed Nicotiana benthamiana protoplasts using a dual-luciferase reporter vector, in which it is possible to analyze the effect of mutated and non-mutated uORFs by dividing the expression of luciferase by that of Renilla-luciferase (LUC/REN)

    Production of selenium nanoparticles in Pseudomonas putida KT2440

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    Selenium (Se) is an essential element for the cell that has multiple applications in medicine and technology; microorganisms play an important role in Se transformations in the environment. Here we report the previously unidentified ability of the soil bacterium Pseudomonas putida KT2440 to synthesize nanoparticles of elemental selenium (nano-Se) from selenite. Our results show that P. putida is able to reduce selenite aerobically, but not selenate, to nano-Se. Kinetic analysis indicates that, in LB medium supplemented with selenite (1 mM), reduction to nano-Se occurs at a rate of 0.444 mmol L−1 h−1 beginning in the middle-exponential phase and with a final conversion yield of 89%. Measurements with a transmission electron microscope (TEM) show that nano-Se particles synthesized by P. putida have a size range of 100 to 500 nm and that they are located in the surrounding medium or bound to the cell membrane. Experiments involving dynamic light scattering (DLS) show that, in aqueous solution, recovered nano-Se particles have a size range of 70 to 360 nm. The rapid kinetics of conversion, easy retrieval of nano-Se and the metabolic versatility of P. putida offer the opportunity to use this model organism as a microbial factory for production of selenium nanoparticles.Universidad de Costa Rica/[809-B5-A68]/UCR/Costa RicaCentro Nacional de Innovaciones Biotecnológicas/[]/CENIBiot/Costa RicaBio-SEA/[]//FranciaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Electroquímica y Energía Química (CELEQ)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

    Screening for frailty in older adults using a self-reported instrument

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    OBJECTIVE To validate a screening instrument using self-reported assessment of frailty syndrome in older adults. METHODS This cross-sectional study used data from the Saúde, Bem-estar e Envelhecimento study conducted in Sao Paulo, SP, Southeastern Brazil. The sample consisted of 433 older adult individuals (≥ 75 years) assessed in 2009. The self-reported instrument can be applied to older adults or their proxy respondents and consists of dichotomous questions directly related to each component of the frailty phenotype, which is considered the gold standard model: unintentional weight loss, fatigue, low physical activity, decreased physical strength, and decreased walking speed. The same classification proposed in the phenotype was utilized: not frail (no component identified); pre-frail (presence of one or two components), and frail (presence of three or more components). Because this is a screening instrument, “process of frailty” was included as a category (pre-frail and frail). Cronbach’s α was used in psychometric analysis to evaluate the reliability and validity of the criterion, the sensitivity, the specificity, as well as positive and negative predictive values. Factor analysis was used to assess the suitability of the proposed number of components. RESULTS Decreased walking speed and decreased physical strength showed good internal consistency (α = 0.77 and 0.72, respectively); however, low physical activity was less satisfactory (α = 0.63). The sensitivity and specificity for identifying pre-frail individuals were 89.7% and 24.3%, respectively, while those for identifying frail individuals were 63.2% and 71.6%, respectively. In addition, 89.7% of the individuals from both the evaluations were identified in the “process of frailty” category. CONCLUSIONS The self-reported assessment of frailty can identify the syndrome among older adults and can be used as a screening tool. Its advantages include simplicity, rapidity, low cost, and ability to be used by different professionals
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