Mapeamento de QTLs associados com a tolerância ao alumínio em milho (Zea mays L.).

xSuplemento. Edição dos resumos do 46º Congresso Nacional de Genética, Águas de Lindóia, SP, 2000

Prospecting sugarcane genes involved in aluminum tolerance.

Aluminium is one of the major factors that affect plant development in acid soils, causing a substantial reduction in yield in many crops. In South America, about 66% of the land surface is made up of acid soils where high aluminium saturation is one of the main limiting factors for agriculture. The biochemical and molecular basis of aluminium tolerance in plants is far from being completely understood despite a growing number of studies, and in the specific case of sugarcane there are virtually no reports on the effects of gene regulation on aluminium stress. The objective of the work presented in this paper was to prospect the sugarcane expressed sequence tag (SUCEST) data bank for sugarcane genes related to several biochemical pathways known to be involved in the responses to aluminium toxicity in other plant species and yeast. Sugarcane genes similar to most of these genes were found, including those coding for enzymes that alleviate oxidative stress or combat infection by pathogens and those which code for proteins responsible for the release of organic acids and signal transducers. The role of these genes in aluminium tolerance mechanisms is reviewed. Due to the high level of genomic conservation in related grasses such as maize, barley, sorghum and sugarcane, these genes may be valuable tools which will help us to better understand and to manipulate aluminium tolerance in these species

Introdução de genes em segmentos foliares de cupuaçu (Theobroma grandiflorum schumm.) usando biobalística.

A técnica da biobalística foi utilizada com o objetivo de adaptar um protocolo para transformação de plantas de cupuaçu. Segmentos foliares de cupuaçu foram bombardeados com um plasmídio contendo o gene reportador da antocianina, utilizando-se as pressões de hélio de 650, 1000 e 1100psi. Após o bombardeamento, os explantes foram transferidos para meio MS por 24 horas e, após este período de incubação, pontos vermelhos foram detectados utilizando-se um estereomicroscópio Stemi SVII Zeiss (Germany). A expressão do gene da antocianina foi observada nas pressões de 650 e lOOOpsi, entretanto necroses foram encontradas na pressão de 11OOpsi. Demonstrou-se que os genes CI e R' da síntese de antocianina, sob o controle do promotor 35S, podem ser utilizados como repórteres para o monitoramento dos eventos de transformação em cupuaçu

The challenge of modelling nitrogen management at the field scale : simulation and sensitivity analysis of N2O fluxes across nine experimental sites using DailyDayCent

Peer reviewedPublisher PD

Indução de calos embriogênicos em explantes de cupuacuzeiro.

Objetivou-se a indução de calos embriogênicos em cupuaçuzeiro, em função do tipo de explante e meio de cultura. Foram testados como explantes, segmentos cotiledonares e eixos embrionários divididos em três partes: região da plúmula, radícula e hipocótilo. Os explantes foram cultivados em 2 diferentes meios de cultura: 1) MS suplementado com 2,4-D (1 mg L-1) e Cinetina (0,25 mg L-1); 2) MS acrescido de ANA (5 mg L-1) e Cinetina (0,25 mg L-1). Constatou-se que a região do hipocótilo foi a parte mais responsiva do eixo embrionário, formando calos com aspecto branco e friável. As auxinas testadas nos meios não estimularam o processo embriogênico em calos de cupuaçuzeiro

Rapid detection of mobilized colistin resistance using a nucleic acid based lab-on-a-chip diagnostic system

The increasing prevalence of antimicrobial resistance is a serious threat to global public health. One of the most concerning trends is the rapid spread of Carbapenemase-Producing Organisms (CPO), where colistin has become the last-resort antibiotic treatment. The emergence of colistin resistance, including the spread of mobilized colistin resistance (mcr) genes, raises the possibility of untreatable bacterial infections and motivates the development of improved diagnostics for the detection of colistin-resistant organisms. This work demonstrates a rapid response for detecting the most recently reported mcr gene, mcr−9, using a portable and affordable lab-on-a-chip (LoC) platform, offering a promising alternative to conventional laboratory-based instruments such as real-time PCR (qPCR). The platform combines semiconductor technology, for non-optical real-time DNA sensing, with a smartphone application for data acquisition, visualization and cloud connectivity. This technology is enabled by using loop-mediated isothermal amplification (LAMP) as the chemistry for targeted DNA detection, by virtue of its high sensitivity, specificity, yield, and manageable temperature requirements. Here, we have developed the first LAMP assay for mcr−9 - showing high sensitivity (down to 100 genomic copies/reaction) and high specificity (no cross-reactivity with other mcr variants). This assay is demonstrated through supporting a hospital investigation where we analyzed nucleic acids extracted from 128 carbapenemase-producing bacteria isolated from clinical and screening samples and found that 41 carried mcr−9 (validated using whole genome sequencing). Average positive detection times were 6.58 ± 0.42 min when performing the experiments on a conventional qPCR instrument (n = 41). For validating the translation of the LAMP assay onto a LoC platform, a subset of the samples were tested (n = 20), showing average detection times of 6.83 ± 0.92 min for positive isolates (n = 14). All experiments detected mcr−9 in under 10 min, and both platforms showed no statistically significant difference (p-value > 0.05). When sample preparation and throughput capabilities are integrated within this LoC platform, the adoption of this technology for the rapid detection and surveillance of antimicrobial resistance genes will decrease the turnaround time for DNA detection and resistotyping, improving diagnostic capabilities, patient outcomes, and the management of infectious diseases

Overexpression of the Cell Cycle Inhibitor p16INK4a Promotes a Prothrombotic Phenotype Following Vascular Injury in Mice

Age-associated cellular senescence is thought to promote vascular dysfunction. p16INK4a is a cell cycle inhibitor that promotes senescence and is upregulated during normal aging. In this study, we examine the contribution of p16INK4a overexpression on venous thrombosis

Genome-wide association studies for methane production in dairy cattle

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Genomic selection has been proposed for the mitigation of methane (CH4) emissions by cattle because there is considerable variability in CH4 emissions between individuals fed on the same diet. The genome-wide association study (GWAS) represents an important tool for the detection of candidate genes, haplotypes or single nucleotide polymorphisms (SNP) markers related to characteristics of economic interest. The present study included information for 280 cows in three dairy production systems in Mexico: 1) Dual Purpose (n = 100), 2) Specialized Tropical Dairy (n = 76), 3) Familiar Production System (n = 104). Concentrations of CH4 in a breath of individual cows at the time of milking (MEIm) were estimated through a system of infrared sensors. After quality control analyses, 21,958 SNPs were included. Associations of markers were made using a linear regression model, corrected with principal component analyses. In total, 46 SNPs were identified as significant for CH4 production. Several SNPs associated with CH4 production were found at regions previously described for quantitative trait loci of composition characteristics of meat, milk fatty acids and characteristics related to feed intake. It was concluded that the SNPs identified could be used in genomic selection programs in developing countries and combined with other datasets for global selection

Quintessential Maldacena-Maoz Cosmologies

Maldacena and Maoz have proposed a new approach to holographic cosmology based on Euclidean manifolds with disconnected boundaries. This approach appears, however, to be in conflict with the known geometric results [the Witten-Yau theorem and its extensions] on spaces with boundaries of non-negative scalar curvature. We show precisely how the Maldacena-Maoz approach evades these theorems. We also exhibit Maldacena-Maoz cosmologies with [cosmologically] more natural matter content, namely quintessence instead of Yang-Mills fields, thereby demonstrating that these cosmologies do not depend on a special choice of matter to split the Euclidean boundary. We conclude that if our Universe is fundamentally anti-de Sitter-like [with the current acceleration being only temporary], then this may force us to confront the holography of spaces with a connected bulk but a disconnected boundary.Comment: Much improved exposition, exponent in Cai-Galloway theorem fixed, axionic interpretation of scalar explained, JHEP version. 33 pages, 3 eps figure