955 resultados para Genetic-markers
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Therapygenetics, the study of genetic determinants of response to psychological therapies, is in its infancy. Here, we investigate whether single-nucleotide polymorphisms in nerve growth factor (NGF) (rs6330) and brain-derived neutrotrophic factor (BDNF) (rs6265) genes predict the response to cognitive behaviour therapy (CBT). Neurotrophic genes represent plausible candidate genes: they are implicated in synaptic plasticity, response to stress, and are widely expressed in brain areas involved in mood and cognition. Allelic variation at both loci has shown associations with anxiety-related phenotypes. A sample of 374 anxiety-disordered children with white European ancestry was recruited from clinics in Reading, UK, and in Sydney, Australia. Participants received manualised CBT treatment and DNA was collected from buccal cells using cheek swabs. Treatment response was assessed at post-treatment and follow-up time points. We report first evidence that children with one or more copies of the T allele of NGF rs6330 were significantly more likely to be free of their primary anxiety diagnosis at follow-up (OR=0.60 (0.42–0.85), P=0.005). These effects remained even when other clinically relevant covariates were accounted for (OR=0.62 (0.41–0.92), P=0.019). No significant associations were observed between BDNF rs6265 and response to psychological therapy. These findings demonstrate that knowledge of genetic markers has the potential to inform clinical treatment decisions for psychotherapeutic interventions.
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Background: Association mapping, initially developed in human disease genetics, is now being applied to plant species. The model species Arabidopsis provided some of the first examples of association mapping in plants, identifying previously cloned flowering time genes, despite high population sub-structure. More recently, association genetics has been applied to barley, where breeding activity has resulted in a high degree of population sub-structure. A major genotypic division within barley is that between winter- and spring-sown varieties, which differ in their requirement for vernalization to promote subsequent flowering. To date, all attempts to validate association genetics in barley by identifying major flowering time loci that control vernalization requirement (VRN-H1 and VRN-H2) have failed. Here, we validate the use of association genetics in barley by identifying VRN-H1 and VRN-H2, despite their prominent role in determining population sub-structure. Results: By taking barley as a typical inbreeding crop, and seasonal growth habit as a major partitioning phenotype, we develop an association mapping approach which successfully identifies VRN-H1 and VRN-H2, the underlying loci largely responsible for this agronomic division. We find a combination of Structured Association followed by Genomic Control to correct for population structure and inflation of the test statistic, resolved significant associations only with VRN-H1 and the VRN-H2 candidate genes, as well as two genes closely linked to VRN-H1 (HvCSFs1 and HvPHYC). Conclusion: We show that, after employing appropriate statistical methods to correct for population sub-structure, the genome-wide partitioning effect of allelic status at VRN-H1 and VRN-H2 does not result in the high levels of spurious association expected to occur in highly structured samples. Furthermore, we demonstrate that both VRN-H1 and the candidate VRN-H2 genes can be identified using association mapping. Discrimination between intragenic VRN-H1 markers was achieved, indicating that candidate causative polymorphisms may be discerned and prioritised within a larger set of positive associations. This proof of concept study demonstrates the feasibility of association mapping in barley, even within highly structured populations. A major advantage of this method is that it does not require large numbers of genome-wide markers, and is therefore suitable for fine mapping and candidate gene evaluation, especially in species for which large numbers of genetic markers are either unavailable or too costly.
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BACKGROUND: Obesity is associated with vitamin D deficiency, and both are areas of active public health concern. We explored the causality and direction of the relationship between body mass index (BMI) and 25-hydroxyvitamin D [25(OH)D] using genetic markers as instrumental variables (IVs) in bi-directional Mendelian randomization (MR) analysis. METHODS AND FINDINGS: We used information from 21 adult cohorts (up to 42,024 participants) with 12 BMI-related SNPs (combined in an allelic score) to produce an instrument for BMI and four SNPs associated with 25(OH)D (combined in two allelic scores, separately for genes encoding its synthesis or metabolism) as an instrument for vitamin D. Regression estimates for the IVs (allele scores) were generated within-study and pooled by meta-analysis to generate summary effects. Associations between vitamin D scores and BMI were confirmed in the Genetic Investigation of Anthropometric Traits (GIANT) consortium (n = 123,864). Each 1 kg/m(2) higher BMI was associated with 1.15% lower 25(OH)D (p = 6.52×10⁻²⁷). The BMI allele score was associated both with BMI (p = 6.30×10⁻⁶²) and 25(OH)D (-0.06% [95% CI -0.10 to -0.02], p = 0.004) in the cohorts that underwent meta-analysis. The two vitamin D allele scores were strongly associated with 25(OH)D (p≤8.07×10⁻⁵⁷ for both scores) but not with BMI (synthesis score, p = 0.88; metabolism score, p = 0.08) in the meta-analysis. A 10% higher genetically instrumented BMI was associated with 4.2% lower 25(OH)D concentrations (IV ratio: -4.2 [95% CI -7.1 to -1.3], p = 0.005). No association was seen for genetically instrumented 25(OH)D with BMI, a finding that was confirmed using data from the GIANT consortium (p≥0.57 for both vitamin D scores). CONCLUSIONS: On the basis of a bi-directional genetic approach that limits confounding, our study suggests that a higher BMI leads to lower 25(OH)D, while any effects of lower 25(OH)D increasing BMI are likely to be small. Population level interventions to reduce BMI are expected to decrease the prevalence of vitamin D deficiency.
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The availability of crop specimens archived in herbaria and old seed collections represent valuable resources for the analysis of plant genetic diversity and crop domestication. The ability to extract ancient DNA (aDNA) from such samples has recently allowed molecular genetic investigations to be undertaken in ancient materials. While analyses of aDNA initially focused on the use of markers which occur in multiple copies such as the internal transcribed spacer region (ITS) within ribosomal DNA and those requiring amplification of short DNA regions of variable length such as simple sequence repeats (SSRs), emphasis is now moving towards the genotyping of single nucleotide polymorphisms (SNPs), traditionally undertaken in aDNA by Sanger sequencing. Here, using a panel of barley aDNA samples previously surveyed by Sanger sequencing for putative causative SNPs within the flowering-time gene PPD-H1, we assess the utility of the Kompetitive Allele Specific PCR (KASP) genotyping platform for aDNA analysis. We find KASP to out-perform Sanger sequencing in the genotyping of aDNA samples (78% versus 61% success, respectively), as well as being robust to contamination. The small template size (≥46 bp) and one-step, closed-tube amplification/genotyping process make this platform ideally suited to the genotypic analysis of aDNA, a process which is often hampered by template DNA degradation and sample cross-contamination. Such attributes, as well as its flexibility of use and relatively low cost, make KASP particularly relevant to the genetic analysis of aDNA samples. Furthermore, KASP provides a common platform for the genotyping and analysis of corresponding SNPs in ancient, landrace and modern plant materials. The extended haplotype analysis of PPD-H1 undertaken here (allelic variation at which is thought to be important for the spread of domestication and local adaptation) provides further resolution to the previously identified geographic cline of flowering-time allele distribution, illustrating how KASP can be used to aid genetic analyses of aDNA from plant species. We further demonstrate the utility of KASP by genotyping ten additional genetic markers diagnostic for morphological traits in barley, shedding light on the phenotypic traits, alleles and allele combinations present in these unviable ancient specimens, as well as their geographic distributions.
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Epidendrum puniceoluteum is an endemic orchid of Atlantic Rainforest, restricted to few populations only due to the destruction and fragmentation of its native habitat. Here, we report on the development of 10 microsatellite markers isolated from this orchid species. Genetic variability was characterized in two distant populations from Brazil coast. The number of alleles observed for each locus ranged from two to 12 and with an average of 6.4 alleles per locus. These microsatellites should be valuable tools for studying both fine-scale genetic structure of scattered E. puniceoluteum population and patterns will be useful genetic markers for other closely related taxa.
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Xanthomonadales comprises one of the largest phytopathogenic bacterial groups, and is currently classified within the gamma-proteobacteria. However, the phylogenetic placement of this group is not clearly resolved, and the results of different studies contradict one another. In this work, the evolutionary position of Xanthomonadales was determined by analyzing the presence of shared insertions and deletions (INDELs) in highly conserved proteins. Several distinctive insertions found in most of the members of the gamma-proteobacteria are absent in Xanthomonadales and groups such as Legionelalles, Chromatiales, Methylococcales, Thiotrichales and Cardiobacteriales. These INDELs were most likely introduced after the branching of Xanthomonadales from most of the gamma-proteobacteria and provide evidence for the phylogenetic placement of the early gamma-proteobacteria. Moreover, other proteins contain insertions exclusive to the Xanthomonadales order, confirming that this is a monophyletic group and provide important specific genetic markers. Thus, the data presented clearly support the Xanthomonadales group as an independent subdivision, and constitute one of the deepest branching lineage within the gamma-proteobacteria clade. (C) 2009 Elsevier Inc. All rights reserved.
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We characterized sequences from genes encoding cathepsin L-like (CatL-like) cysteine proteases from African and South American isolates of Trypanosoma vivax and T. vivax-like organisms, and evaluated their suitability as genetic markers for population structure analysis and diagnosis. Phylogenetic analysis of sequences corresponding to CatL-like catalytic domains revealed substantial polymorphism, and clades of sequences (TviCatL1-9) were separated by large genetic distances. TviCatL1-4 sequences were from cattle isolates from West Africa (Nigeria and Burkina Faso) and South America (Brazil and Venezuela), which belonged to the same T. vivax genotype. T. vivax-like genotypes from East Africa showed divergent sequences, including TviCatL5-7 for isolates from Mozambique and TviCatL8-9 for an isolate from Kenya. Phylogenetic analysis of CatL-like gene data supported the relationships among trypanosome species reflected in the phylogenies based on the analysis of small subunit (SSU) of ribosomal RNA gene sequence data. The discovery of different CatL-like sequences for each genotype, defined previously by ribosomal DNA data, indicate that these sequences provide useful targets for epidemiological and population genetic studies. Regions in CatL-like sequences shared by all T. vivax genotypes but not by other trypanosomes allowed the establishment of a specific and sensitive diagnostic PCR for epidemiological studies in South America and Africa. (C) 2008 Elsevier Ltd. All rights reserved.
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Preeclampsia is a multifactorial disease of unknown etiology that features with wide clinical symptoms, ranging from mild preeclampsia to severe forms, as eclampsia and HELLP syndrome. As a complex disease, preeclampsia is also influenced by genetic and environmental factors. Aiming to identify preeclampsia susceptibility genes, we genotyped a total of 22 genetic markers (single nucleotides polymorphisms SNPs) distributed in six candidates genes (ACVR2A, FLT1, ERAP1, ERAP2, LNPEP e CRHBP). By a case-control approach, the genotypic frequencies were compared between normotensive (control group) and preeclamptic women. The case s group was classified according to the disease clinical form in: preeclampsia, eclampsia and HELLP syndrome. As results we found the following genetic association: 1) ACVR2A and preeclampsia; 2) FLT1 and severe preeclampsia; 3) ERAP1 and eclampsia; 4) FLT1 and HELLP syndrome. When stratifying preeclampsia group according to symptoms severity (mild and severe preeclampsia) or according to the time of onset (early and late preeclampsia), it was detected that early preeclampsia is strongly associated to risk preeclampsia, eclampsia and HELLP syndrome have different genetic bases, although FLT1 gene seems to be involved in preeclampsia and HELLP syndrome pathophisiology
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The elaboration of profiles with characteristics that can be parameters in the different categories of sports modalities and the investment in scientific studies have revealed a significant importance in the development of new generations of athletes. Based in the exposed, the purpose of this study was to identify and compare the somatotype characteristics, physical qualities and genetic markers of Brazilian male volleyball players in the 14-17 category playing at different levels (international, national and regional). We used a scale, stadiometer, pachymeter, and adipometer to evaluate somatotype, attack and block reach test, medicine ball toss, 30-meter agility test , the AAHPER -30 test to evaluate basic physical qualities and the dermatoglyphic method to identify genetic markers. The results show the superiority of the national team over the other squads in the somatotype component (ectomorphy), and in the level of basic physical qualities. We found no significant difference in genetic markers among the teams studied. We conclude that Brazilian volleyball players at different performance levels have characteristics peculiar to the sport, with height and physical qualities being significantly different among these teams. The results confirm de necessity of knowing the athletes specific characteristics when dealing with high performance teams using nutrition, medicine, physiology and genetics specific knowledges to achieve a better sportive development
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The aim of this research was to analyse genetic markers, anthropometry and basic physical qualities in the differret stages of sexual maturation in swimmers in Paraíba. It is characterised as a descriptive cross sectional study. The sample was composed of 119 swimmers (males) that were divided among the stages of sexual maturation, from 7 to 17,9 years of age. They were associated to a local federation, the Confederação Brasileira de Desportes Aquáticos. The tests used were: genetic markers dermatoglyphics; Anthropometry body mass, stature, arm span, fat percentage and somatotype; physical qualities speed tests (25 meters crawl), strength (vertical jump) to inferior limbs, verarm throwing arremesso of a 2kg medicineball to superior limbs and abdominal), resistence (12 minutes to swimming), agility (he multistage 20-meter shuttle run test), flexibility (sit and reach test ) and coodination (stroke index); power of swimming (mean velocity in 25 meters mutiplied by body mass) and the self assessment of the sexual maturation supervised by a pediatric specialist. In the analyses we used the test normality of Shapiro-Wilk, then, we used ANOVA- one way followed by Post-Hoc test of Scheffé. The data showed in dermatogliphics a genetic tendence to velocity (L>W) with a predominance of the meso-ectomorphic somatotype profile; in relation to the physical qualities there was an evolution of the results in every stage due to the antropometric variables, except in the coordination tests. There were no significative differences between the stages. We conclude that swimming in Paraíba is composed of a signicative number of velocists with a mesomorph somatotype profile and low fat percentage, and that made it posssible to us to recomend that the trainings must be individual and according to personal characteristics of each athlete, and that the used variables must be specific for every region of the country. This dissertation presents a relation of multidiciplinar interface and its content has an application in Physical Education and Medicine
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O Pinus caribaea var. hondurensis Barret & Golfari tem elevada importância como espécie comercialmente plantada; aproximadamente 1,8 milhões de hectares estão ocupados por plantios desta espécie no Brasil. O trabalho teve como objetivo verificar por meio de marcadores microssatélites a variabilidade genética em Pinus caribaea var. hondurensis, bem como sua manutenção durante o processo de melhoramento genético, dentro de uma população- base de melhoramento, uma população de matrizes selecionadas e uma população melhorada F1. Para a realização das análises foi necessária a transferência de primers desenvolvidos para locos microssatélites de outras espécies do gênero. Dos 20 pares de primers testados, 8 foram transferidos para a espécie (RPS 25b, RPS 150, PSM 2, PR 4.6, PtTX 2037, PtTX 3029, RPTest 01 e RPTest 09). Verificou-se a existência de endogamia entre e dentro das populações estudadas, e o maior valor observado entre as populações foi F ST = 0,0213 (população base e F1). A heterozigosidade média observada e a heterozigosidade esperada na população-base foram, respectivamente, H0 = 0,2469 e He = 0,2489. A maior distância genética (D = 0,0119) foi observada entre as populações-base e a população melhorada F1. Através da distância genética entre as matrizes, foram indicados 10 cruzamentos potenciais entre as matrizes mais contrastantes, almejando a obtenção de vigor de híbrido nas progênies obtidas a partir destes cruzamentos.
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A Egeria najas é uma espécie aquática submersa nativa da bacia hidrográfica do rio Paraná. Com o represamento das águas do rio para geração de energia elétrica a espécie tem mudado seu comportamento de colonização dos leitos dos rios e ocorrido em grandes maciços dentro da represa de Jupiá e rios afluentes. Essa planta tem causado problemas por obstruir a passagem de água para as turbinas de geração de energia elétrica. Coletas de material vegetativo foram realizadas na represa e afluentes do rio Paraná para análise da variabilidade isoenzimática e de DNA. A análise isoenzimática mostrou haver somente quatro classes de diferentes biotipos. No entanto, utilizando-se os procedimentos de RAPD, observou-se que a espécie possui grande variabilidade genética. O represamento das águas também está permitindo o acumulo de variabilidade no local e promovendo um aumento de variabilidade por meio de possíveis cruzamentos entre genótipos diferentes. Os resultados também possibilitaram inferir sobre as possíveis rotas de migração de material genético para colonização da represa e rios afluentes.
Caracterização da resistência do algodoeiro a Ramularia areola e variabilidade molecular do patógeno
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This research was conducted with the aim to study the genetic and pathogenic structure of Ramularia areola isolates collected in Brazil and to characterize the resistance response in cotton plants to ramularia spot. The genetic variability of 28 isolates of R. areola was studied using RAPD markers. The pathogenicity evaluation was realized by the inoculation of 6 isolates on cotton varieties Guazuncho-2 (Gossypium hirsutum) and VH8-4602 (Gossypium barbadense). The inheritance of disease resistance was studied using an artificially inoculated population of F2 individuals derived from the intercross of Guazuncho-2 (susceptible variety) end VH8-4602 (resistant variety), and also the parents and F1 individuals. Molecular polymorphism between the G. hisutum varieties DeltaOpal (suscetible) and CNPA CO-11612 (resistant) was estimated by 118 SSR and 24 AFLP markers. The parental genotypes Guazuncho-2 and VH8-4602 were selected for mapping, and then Recombinant Inbred Lines (RIL´s) derived from this crossing were evaluated with SSR 12 markers. The analysis of population structure of R. areola revealed that the three subpopulations were genetically simillar (Gst=0.18), and the isolates from Goiás and Minas Gerais were more similar to each other (0,92). This probability can be related to the relatively high gene flow among the three subpopulations (Nm=2.20). The isolates R. areola 9.1, from Minas Gerais State and 8.1 and 8.3 from Goiás State were the most aggressive ones to the susceptible variety Guazuncho-2. The variety VH8-4602 presented high level of resistance to ramularia spot. No differential interaction was observed between the pathogens and the analyzed varieties, and the resistance was classified as horizontal. The quantification of disease by number of necrotic lesions and number of spores in individual plants of F1 and F2 generations from the crossing between the varieties Guazuncho-2 and VH8-4602 presented continuous distribution, suggesting polygenic resistance. The resistance is probabilly recessive, since necrotic lesions and sporulation were observed on F1 plants. The molecular polymorphism between DeltaOpal e CNPA CO-11612 lineages was low (6%), then would be difficult to accomplish molecular mapping of disease resistance using this intercross. With the genotyping of the RIL s it was verified that 25% of the markers segregated in the proportions proposed by Mendel s Law and 75% of the studied markers presented segregation distortion in favor to the parental G. hirsutum. Both the low genetic variability of the pathogen and the number of resistance genes suggest that durable genetic resitance may be achieved
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The main goal of our research was to search for SSRs in the Eucalyptus EST FORESTs database (using a software for mining SSR-motifs). With this objective, we created a database for cataloging Eucalyptus EST-derived SSRs, and developed a bioinformatics tool, named Satellyptus, for finding and analyzing microsatellites in the Eucalyptus EST database. The search for microsatellites in the FORESTs database containing 71,115 Eucalyptus EST sequences (52.09 Mb) revealed 20,530 SSRs in 15,621 ESTs. The SSR abundance detected on the Eucalyptus ESTs database (29% or one microsatellite every four sequences) is considered very high for plants. Amongst the categories of SSR motifs, the dimeric (37%) and trimeric ones (33%) predominated. The AG/CT motif was the most frequent (35.15%) followed by the trimeric CCG/CGG (12.81%). From a random sample of 1,217 sequences, 343 microsatellites in 265 SSR-containing sequences were identified. Approximately 48% of these ESTs containing microsatellites were homologous to proteins with known biological function. Most of the microsatellites detected in Eucalyptus ESTs were positioned at either the 5 or 3 end. Our next priority involves the design of flanking primers for codominant SSR loci, which could lead to the development of a set of microsatellite-based markers suitable for marker-assisted Eucalyptus breeding programs.