2,662 research outputs found

    A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers.

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    Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes

    Genetic profiles of Mycobacterium bovis from a cattle herd in southernmost Brazil.

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    Mycobacterium bovis is the agent of bovine tuberculosis, a disease endemic to all Brazilian states. Molecular typing techniques help to stratify and refine data, providing information that facilitates epidemiological research. In this study, MIRU-VNTR, targeting 24 loci, was employed to identify and characterize the genetic groups of M. bovis isolates obtained from an outbreak of bovine tuberculosis. Eighteen acid-fast bacilli isolates, obtained from bovine tissue samples, and reactive to the comparative cervical tuberculin test, were identified as species of the M. tuberculosis complex, and were genotyped by MIRU-VNTR with 24 primer pairs. Genotyping revealed three genetic profiles comprising one with 15 isolates (83.3%), one with two isolates (11.1%), and one profile with one unique isolate (5.6%). This distinction was achieved with the MIRU 31 primer, which resulted in clustering of two isolates into the same profile, and ETR A, B, and C, which discriminated the isolate with a unique profile. The occurrence of clustered isolates is indicative of recent transmission, whereas isolates with a unique profile suggest reactivation of latent infection. The presence of different M. bovis genotypes in the same herd suggests movement of infected animals or different sources of intra-herd infection. Use of the MIRU-VNTR molecular epidemiology technique in M. bovis isolates obtained from an outbreak of bovine tuberculosis in Rio Grande do Sul state demonstrated the genetic diversity of circulating strains, despite the presence of a predominant group.Título em português: Perfis genéticos de Mycobacterium bovis em um rebanho bovino no extremo sul do Brasil

    Method for obtaining high-resolution proteomic analysis from pericarps of guarana

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    Guarana has great agricultural potential and is largely used therapeutically and in the production of non-alcoholic energy drinks. Genomic and proteomic studies are crucial to identify proteins that play central roles in the maintenance and viability of fruits, as well as to identify proteins related to the main metabolic pathways. However, the success of any protein analysis starts with the protein extract preparation, which needs to offer an extract that is free of contaminants. This study aimed to evaluate different extraction methods to obtain high-quantity and high-quality extracts that are compatible with analysis by 2-dimensional electrophoresis and tandem mass spectrometry protein identification. Three different methods were tested: trichloroacetic acid (TCA)/acetone, sodium dodecyl sulfate (SDS)/phenol, and polyvinylpolypyrrolidone (PVPP)/SDS/phenol. The extract obtained from the TCA/acetone precipitation presented low solubility and contamination with lipids and carbohydrates. On the other hand, the quality of the extract gradually improved after using phenol and PVPP/phenol, enabling a yield up to 2 mg/g macerated tissues and the detection of 457 spots by 2-dimensional electrophoresis. The effectiveness of the procedure used was validated by identification of 10 randomly selected proteins by mass spectrometry. The procedure described here can be a starting point for applications using tissues of other organs of guarana or tissues of species that are similar to guarana. © FUNPEC-RP

    How far can we go in simplifying biomonitoring assessments? An integrated analysis of taxonomic surrogacy, taxonomic sufficiency and numerical resolution in a megadiverse region

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    The need for biodiversity conservation is increasing at a rate much faster than the acquisition of knowledge of biodiversity, such as descriptions of new species and mapping species distributions. As global changes are winning the race against the acquisition of knowledge, many researchers resort to the use of surrogate groups to aid in conservation decisions. Reductions in taxonomic and numerical resolution are also desirable, because they could allow more rapid the acquisition of knowledge while requiring less effort, if little important information is lost. In this study, we evaluated the congruence among 22 taxonomic groups sampled in a tropical forest in the Amazon basin. Our aim was to evaluate if any of these groups could be used as surrogates for the others in monitoring programs. We also evaluated if the taxonomic or numerical resolution of possible surrogates could be reduced without greatly reducing the overall congruence. Congruence among plant groups was high, whereas the congruence among most animal groups was very low, except for anurans in which congruence values were only slightly lower than for plants. Liana (Bignoniaceae) was the group with highest congruence, even using genera presence-absence data. The congruence among groups was related to environmental factors, specifically the clay and phosphorous contents of soil. Several groups showed strong spatial clumping, but this was unrelated to the congruence among groups. The high degree of congruence of lianas with the other groups suggests that it may be a reasonable surrogate group, mainly for the other plant groups analyzed, if soil data are not available. Although lianas are difficult to count and identify, the number of studies on the ecology of lianas is increasing. Most of these studies have concluded that lianas are increasing in abundance in tropical forests. In addition to the high congruence, lianas are worth monitoring in their own right because they are sensitive to global warming and the increasing frequency and severity of droughts in tropical regions. Our findings suggest that the use of data on surrogate groups with relatively low taxonomic and numerical resolutions can be a reliable shortcut for biodiversity assessments, especially in megadiverse areas with high rates of habitat conversion, where the lack of biodiversity knowledge is pervasive. (c) 2012 Elsevier Ltd. All rights reserved.PhD scholarship from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq
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