284 research outputs found

    Diverse Cis-Regulatory Mechanisms Contribute to Expression Evolution of Tandem Gene Duplicates

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    The deposited article is a post-print version and has peer review. The deposited article version contains attached the supplementary materials within the pdf.Pairs of duplicated genes generally display a combination of conserved expression patterns inherited from their unduplicated ancestor and newly acquired domains. However, how the cis-regulatory architecture of duplicated loci evolves to produce these expression patterns is poorly understood. We have directly examined the gene-regulatory evolution of two tandem duplicates, the Drosophila Ly6 genes CG9336 and CG9338, which arose at the base of the drosophilids between 40 and 60 million years ago. Comparing the expression patterns of the two paralogs in four Drosophila species with that of the unduplicated ortholog in the tephritid Ceratitis capitata, we show that they diverged from each other as well as from the unduplicated ortholog. Moreover, the expression divergence appears to have occurred close to the duplication event and also more recently in a lineage-specific manner. The comparison of the tissue-specific cis-regulatory modules (CRMs) controlling the paralog expression in the four Drosophila species indicates that diverse cis-regulatory mechanisms, including the novel tissue-specific enhancers, differential inactivation, and enhancer sharing, contributed to the expression evolution. Our analysis also reveals a surprisingly variable cis-regulatory architecture, in which the CRMs driving conserved expression domains change in number, location, and specificity. Altogether, this study provides a detailed historical account that uncovers a highly dynamic picture of how the paralog expression patterns and their underlying cis-regulatory landscape evolve. We argue that our findings will encourage studying cis-regulatory evolution at the whole-locus level in order to understand how interactions between enhancers and other regulatory levels shape the evolution of gene expression.Fundação Calouste Gulbenkian/Instituto Gulbenkian de Ciência; Toulouse RIO Imaging platform; Bloomington Drosophila Stock Center (Indiana, USA); Developmental Studies Hybridoma Bank (Iowa, USA); Drosophila Genomics Resource Center (Indiana, USA); NIH grant: (2P0OD010949); Agence Nationale de la Recherche grant: (ANR-13-ISV7-0001-01); Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/75139/2010, FCT-ANR/BIA-ANM/0003/2013, FCT-EXPL/BEX-GMG/2197/2013).info:eu-repo/semantics/acceptedVersio

    Production of polygalacturonases by aspergillus section Nigri strains in a fixed bed reactor

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    Polygalacturonases (PG) are pectinolytic enzymes that have technological, functional and biological applications in food processing, fruit ripening and plant-fungus interactions, respectively. In the present, study a microtitre plate methodology was used for rapid screening of 61 isolates of fungi from Aspergillus section Nigri to assess production of endo- and exo-PG. Studies of scale-up were carried out in a fixed bed reactor operated under different parameters using the best producer strain immobilised in orange peels. Four experiments were conducted under the following conditions: the immobilised cells without aeration; immobilised cells with aeration; immobilised cells with aeration and added pectin; and free cells with aeration. The fermentation was performed for 168 h with removal of sample every 24 h. Aspergillus niger strain URM 5162 showed the highest PG production. The results obtained indicated that the maximum endo- and exo-PG activities (1.18 U·mL-1 and 4.11 U·mL-1, respectively) were obtained when the reactor was operating without aeration. The microtitre plate method is a simple way to screen fungal isolates for PG activity detection. The fixed bed reactor with orange peel support and using A. niger URM 5162 is a promising process for PG production at the industrial level.M.H.C. Maciel thanks to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil) and Erasmus Mundus External Cooperation Window Lote 17

    Ecosapentanoic acid (EPA) does not affect cell kinetics in peripheral lymphocites from patients with Crohn's disease (CD) according to IL6 174G/C polymorphism

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    Rationale: Omega 3 fatty acids have been shown to be of potential benefit in patients with CD. The aim of the present study was to evaluate whether EPA can modulate the inflammatory response according to different genotypes of IL6G174G/C polymorphism. Methods: Peripheral blood cells were collected from CD patients with different genotypes for IL6 174G/C (GG, n = 16, GC, n = 8, CC, n = 7), and lymphocytes were established in culture media. Replicates with the addition of EPA (25 mM) were analysed in a period of 24h, 48h and 72h. Expression of IL6 e a PGE2 was assessed by ELISA. Apoptosis and cellular proliferation was determined by flow cytometry

    Strategies for Efficient Expression of Heterologous Monosaccharide Transporters in Saccharomyces cerevisiae

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    ABSTRACT: In previous work, we developed a Saccharomyces cerevisiae strain (DLG-K1) lacking the main monosaccharide transporters (hxt-null) and displaying high xylose reductase, xylitol dehydrogenase and xylulokinase activities. This strain proved to be a useful chassis strain to study new glucose/xylose transporters, as SsXUT1 from Scheffersomyces stipitis. Proteins with high amino acid sequence similarity (78-80%) to SsXUT1 were identified from Spathaspora passalidarum and Spathaspora arborariae genomes. The characterization of these putative transporter genes (SpXUT1 and SaXUT1, respectively) was performed in the same chassis strain. Surprisingly, the cloned genes could not restore the ability to grow in several monosaccharides tested (including glucose and xylose), but after being grown in maltose, the uptake of C-14-glucose and C-14-xylose was detected. While SsXUT1 lacks lysine residues with high ubiquitinylation potential in its N-terminal domain and displays only one in its C-terminal domain, both SpXUT1 and SaXUT1 transporters have several such residues in their C-terminal domains. A truncated version of SpXUT1 gene, deprived of the respective 3 '-end, was cloned in DLG-K1 and allowed growth and fermentation in glucose or xylose. In another approach, two arrestins known to be involved in the ubiquitinylation and endocytosis of sugar transporters (ROD1 and ROG3) were knocked out, but only the rog3 mutant allowed a significant improvement of growth and fermentation in glucose when either of the XUT permeases were expressed. Therefore, for the efficient heterologous expression of monosaccharide (e.g., glucose/xylose) transporters in S. cerevisiae, we propose either the removal of lysines involved in ubiquitinylation and endocytosis or the use of chassis strains hampered in the specific mechanism of membrane protein turnover.info:eu-repo/semantics/publishedVersio

    Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.)

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    <p>Abstract</p> <p>Background</p> <p>The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host.</p> <p>Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens. Nevertheless, the physiological significance of these bacteria for mosquitoes has not been established to date. In this study, oral administration of antibiotics was employed in order to examine the contribution of gut bacteria to blood digestion and fecundity in <it>Aedes aegypti</it>.</p> <p>Results</p> <p>The antibiotics carbenicillin, tetracycline, spectinomycin, gentamycin and kanamycin, were individually offered to female mosquitoes. Treatment of female mosquitoes with antibiotics affected the lysis of red blood cells (RBCs), retarded the digestion of blood proteins and reduced egg production. In addition, antibiotics did not affect the survival of mosquitoes. Mosquito fertility was restored in the second gonotrophic cycle after suspension of the antibiotic treatment, showing that the negative effects of antibiotics in blood digestion and egg production in the first gonotrophic cycle were reversible.</p> <p>Conclusions</p> <p>The reduction of bacteria affected RBC lysis, subsequently retarded protein digestion, deprived mosquito from essential nutrients and, finally, oocyte maturation was affected, resulting in the production of fewer viable eggs. These results indicate that <it>Ae. aegypti </it>and its midgut bacteria work in synergism to digest a blood meal.</p> <p>Our findings open new possibilities to investigate <it>Ae. aegypti</it>-associated bacteria as targets for mosquito control strategies.</p

    Motivation for Brazilian Older Adult Women to Join a Community Physical Activity Program Before COVID-19 Pandemic

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    Background: Intrinsic and extrinsic motivational factors can affect the levels of adherence of physical activity (PA) during the aging process. Objectives: Investigate the intrinsic and extrinsic aspects and motivation that led older women to enroll in and adhere to a community PA program before the COVID-19 pandemic. Methods: Data were collected via transversal survey before the COVID-19 pandemic. The sample consisted of 21 women, participants of a PA workshop, aged between 60 to 86 years [< 1-year (n = 8) and ≥ 1-year (n = 13) groups]. Motivation was assessed by the Motivation Inventory for Regular Physical Activity Practice (IMPRAF-54), using the 60th percentile to categorize high and low motivation, and two open questions. For qualitative assessment, content analysis was used and the answers were framed into subcategories regarding the motivation factors for adherence and permanence. Results: That adherence to the program was motivated by sociability purposes [total score: 36.0 (6.0), median (interquartile range)] and pleasure [34.0; (6.0)], while the main motivation for permanence was health [40.0 (11.0)]. Differences were noticed between the groups for sociability [38.0 (3.0) P = 0.030] and competitiveness [9.50 (12.0); P = 0.037] highest medians for the < 1 year group. Furthermore, the factors that least motivated older women were competitiveness and aesthetics. Conclusions: Health and sociability were the main motivators for the practice of physical activity among older adult women. Motivation played a fundamental role in the permanence of older adult women in the physical activity program

    THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

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    Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni

    The Li-age correlation: The Sun is unusually Li deficient for its age

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    This work aims to examine in detail the depletion of lithium in solar twins to better constrain stellar evolution models and investigate its possible connection with exoplanets. We employ spectral synthesis in the region of the asymmetric 6707.75 Å Li I line for a sample of 77 stars plus the Sun. As in previous works based on a smaller sample of solar twins, we find a strong correlation between Li depletion and stellar age. In addition, for the first time we show that the Sun has the lowest Li abundance in comparison with solar twins at similar age (4.6 ± 0.5 Gyr). We compare the lithium content with the condensation temperature slope for a subsample of the best solar twins and determine that the most lithium-depleted stars also have fewer refractory elements. We speculate whether the low lithium content in the Sun might be related to the particular configuration of our Solar system.This study was financed in part by the Coordenac¸ao de ˜ Aperfeic¸oamento de Pessoal de N´ıvel Superior – Brasil (CAPES) – Finance Code 001. JM is thankful for the support of Fundac¸ao de ˜ Amparo a Pesquisa do Estado de S ` ao Paulo (FAPESP, 2014/18100- ˜ 4, 2018/04055-8) and Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnologico (CNPq, Bolsa de Produtividade). LAdS ´ acknowledges the financial support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (project FOUR ACES; grant agreement No. 724427)

    Optimal Cutoff Scores for Dementia and Mild Cognitive Impairment in the Brazilian Version of the Montreal Cognitive Assessment among the Elderly

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    Objective: To propose cutoff scores for the Brazilian version of the Montreal Cognitive Assessment (MoCA-BR) stratified by education in order to detect mild cognitive impairment (MCI) and mild Alzheimer’s disease (AD) in the elderly. Method: A transversal study in health centers was performed on 159 elderly people with 4–12 years of education and 70 of their peers with over 12 years of schooling. The MoCA-BR cutoff scores for screening cognitive impairment were determined based on an ROC curve analysis. Results: The ROC curve analysis indicated that cutoff scores under 20 were good for screening elderly people with cognitive impairment with more than 12 years of education, and scores under 21 were good for screening those with 4–12 years of education. Conclusions: MoCA-BR scores under 21 points (after adding 1 point to the elderly with ≤12 years of education) indicate a need to continue the diagnostic investigation with regular follow-ups
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