241 research outputs found

    From the Ground Up. Assessing the Record of Anticorruption Assistance in Southeastern Europe

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    In this policy paper, based on research findings from twenty case studies of donor-supported projects in Albania, Bosnia and Herzegovina, Bulgaria and Macedonia, we assess the effects of five years of anticorruption projects and high-profile public awareness campaigns in the Southeastern European region. As a starting point, the paper posits that while projects seem to have succeeded in raising demand for reform, solutions to match that demand have yet to be found. The authors question both what reforms or change in particular the projects raised demand for, and what success the solutions applied thus far may claim. The donor community’s failure to meet the high public expectations that their projects fostered comes against a disturbing backdrop of falling trust in democratic institutions in the region. The paper underlines the urgency to respond to citizens’ needs. The authors argue that the impact of reviewed projects was mostly of short duration, if at all. Projects generally failed to create a self-sustaining constituency to further their work, and when success was achieved it often depended heavily on contingent factors such as the presence of a “champion” or an exceptional level of donor resources targeted for a single, receptive client. The most successful projects provided direct benefits to a well-defined constituency. In all cases, the projects listed reducing corruption as one of their core objectives; yet based on interview material and project reports, none of the donors claimed that their projects had effectively reduced corruption. In conclusion, the paper argues that donors should seek to build sustained public demand for a realistic, long-term anticorruption reform agenda. 6 Th is can be achieved by moving away from the fight against corruption per se—characterized by large-scale awareness raising and broad NGO coalitions—and towards mobilizing well-defined constituencies behind focused governance reforms that have a clear impact and benefits for those involved; and by encouraging citizens to fight corruption through the democratic, political mechanisms of representation by supporting, among others, political party reform. If anticorruption reforms are layered within the political process and meet public needs, the long awaited mobilizational potential of the anticorruption agenda might yet be realized.Published versio

    Identification of Ganoderma disease resistance loci using natural field infection of an oil palm multiparental population

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    Multi-parental populations are promising tools for identifying quantitative disease resistance loci. Stem rot caused by Ganoderma boninense is a major threat to palm oil production, with yield losses of up to 80% prompting premature replantation of palms. There is evidence of genetic resistance sources, but the genetic architecture of Ganoderma resistance has not yet been investigated. This study aimed to identify Ganoderma resistance loci using an oil palm multi-parental population derived from nine major founders of ongoing breeding programs. A total of 1200 palm trees of the multi-parental population was planted in plots naturally infected by Ganoderma, and their health status was assessed biannually over 25 yr. The data were treated as survival data, and modeled using the Cox regression model, including a spatial effect to take the spatial component in the spread of Ganoderma into account. Based on the genotypes of 757 palm trees out of the 1200 planted, and on pedigree information, resistance loci were identified using a random effect with identity-by-descent kinship matrices as covariance matrices in the Cox model. Four Ganoderma resistance loci were identified, two controlling the occurrence of the first Ganoderma symptoms, and two the death of palm trees, while favorable haplotypes were identified among a major gene pool for ongoing breeding programs. This study implemented an efficient and flexible QTL mapping approach, and generated unique valuable information for the selection of oil palm varieties resistant to Ganoderma disease

    Mixed model approach for IBD-based QTL mapping in a complex oil palm pedigree

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    Background Elaeis guineensis is the world's leading source of vegetable oil, and the demand is still increasing. Oil palm breeding would benefit from marker-assisted selection but genetic studies are scarce and inconclusive. This study aims to identify genetic bases of oil palm production using a pedigree-based approach that is innovative in plant genetics. Results A quantitative trait locus (QTL) mapping approach involving two-step variance component analysis was employed using phenotypic data on 30852 palms from crosses between more than 300 genotyped parents of two heterotic groups. Genome scans were performed at parental level by modeling QTL effects as random terms in linear mixed models with identity-by-descent (IBD) kinship matrices. Eighteen QTL regions controlling production traits were identified among a large genetically diversified sample from breeding program. QTL patterns depended on the genetic origin, with only one region shared between heterotic groups. Contrasting effects of QTLs on bunch number and weights reflected the close negative correlation between the two traits. Conclusions The pedigree-based approach using data from ongoing breeding programs is a powerful, relevant and economic approach to map QTLs. Genetic determinisms contributing to heterotic effects have been identified and provide valuable information for orienting oil palm breeding strategies. (Résumé d'auteur

    Identification of nitrogen consumption genetic variants in yeast through QTL mapping and bulk segregant RNA-Seq analyses

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    Saccharomyces cerevisiae is responsible for wine must fermentation. In this process, nitrogen represents a limiting nutrient and its scarcity results in important economic losses for the wine industry. Yeast isolates use different strategies to grow in poor nitrogen environments and their genomic plasticity enables adaptation to multiple habitats through improvements in nitrogen consumption. Here, we used a highly recombinant S. cerevisiae multi-parent population (SGRP-4X) derived from the intercross of four parental strains of different origins to identify new genetic variants responsible for nitrogen consumption differences during wine fermentation. Analysis of 165 fully sequenced F12 segregants allowed us to map 26 QTL in narrow intervals for 14 amino acid sources and ammonium, the majority of which represent genomic regions previously unmapped for these traits. To complement this strategy, we performed Bulk segregant RNA-seq (BSR-seq) analysis in segregants exhibiting extremely high and low ammonium consumption levels. This identified several QTL overlapping differentially expressed genes and refined the gene candidate search. Based on these approaches, we were able to validate ARO1, PDC1, CPS1, ASI2, LYP1, and ALP1 allelic variants underlying nitrogen consumption differences between strains, providing evidence of many genes with small phenotypic effects. Altogether, these variants significantly shape yeast nitrogen consumption with important implications for evolution, ecological, and quantitative genomics

    Pedigree-based linkage map in two genetic groups of oil palm

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    A microsatellite genetic linkage map was constructed for oil palm (Elaeis guineensis Jacq.) using segregation data from two three/four-generation outbred pedigrees. The first was mainly a Deli population and the second consisted of La Mé and Yangambi populations. A total of 363 microsatellite markers (SSR) were genotyped and analyzed with CRI-MAP software. On the initial 363 SSR, 252 and 277 SSR markers for the first and second groups, respectively, were mapped in 16 linkage groups. The maps covered 2078 and 1845 cM, with an average density of one marker every 9 and 7 cM. An integrated map was built, grouping 281 markers on 1935 cM, with an average density of one marker every 7.4 cM. The linear orders of markers among the three genetic maps and with the physical map were highly consistent. These results showed the ability to override the existing experimental limits for linkage mapping in oil palm, namely a limited number of palms per cross. This represents the first step towards efficient pedigree-based quantitative trait locus (QTL) mapping using the first intercrossed generations in current breeding programs. (Résumé d'auteur

    Genomic preselection with genotyping-bysequencing increases performance of commercial oil palm hybrid crosses

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    Background: There is great potential for the genetic improvement of oil palm yield. Traditional progeny tests allow accurate selection but limit the number of individuals evaluated. Genomic selection (GS) could overcome this constraint. We estimated the accuracy of GS prediction of seven oil yield components using A × B hybrid progeny tests with almost 500 crosses for training and 200 crosses for independent validation. Genotyping-by-sequencing (GBS) yielded +5000 single nucleotide polymorphisms (SNPs) on the parents of the crosses. The genomic best linear unbiased prediction method gave genomic predictions using the SNPs of the training and validation sets and the phenotypes of the training crosses. The practical impact was illustrated by quantifying the additional bunch production of the crosses selected in the validation experiment if genomic preselection had been applied in the parental populations before progeny tests. Results: We found that prediction accuracies for cross values plateaued at 500 to 2000 SNPs, with high (0.73) or low (0.28) values depending on traits. Similar results were obtained when parental breeding values were predicted. GS was able to capture genetic differences within parental families, requiring at least 2000 SNPs with less than 5% missing data, imputed using pedigrees. Genomic preselection could have increased the selected hybrids bunch production by more than 10%. Conclusions: Finally, preselection for yield components using GBS is the first possible application of GS in oil palm. This will increase selection intensity, thus improving the performance of commercial hybrids. Further research is required to increase the benefits from GS, which should revolutionize oil palm breeding

    Anticorruption agencies: expressive, constructivist and strategic uses

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    Structural basis for human mitochondrial tRNA maturation

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    \ua9 The Author(s) 2024. The human mitochondrial genome is transcribed into two RNAs, containing mRNAs, rRNAs and tRNAs, all dedicated to produce essential proteins of the respiratory chain. The precise excision of tRNAs by the mitochondrial endoribonucleases (mt-RNase), P and Z, releases all RNA species from the two RNA transcripts. The tRNAs then undergo 3′-CCA addition. In metazoan mitochondria, RNase P is a multi-enzyme assembly that comprises the endoribonuclease PRORP and a tRNA methyltransferase subcomplex. The requirement for this tRNA methyltransferase subcomplex for mt-RNase P cleavage activity, as well as the mechanisms of pre-tRNA 3′-cleavage and 3′-CCA addition, are still poorly understood. Here, we report cryo-EM structures that visualise four steps of mitochondrial tRNA maturation: 5′ and 3′ tRNA-end processing, methylation and 3′-CCA addition, and explain the defined sequential order of the tRNA processing steps. The methyltransferase subcomplex recognises the pre-tRNA in a distinct mode that can support tRNA-end processing and 3′-CCA addition, likely resulting from an evolutionary adaptation of mitochondrial tRNA maturation complexes to the structurally-fragile mitochondrial tRNAs. This subcomplex can also ensure a tRNA-folding quality-control checkpoint before the sequential docking of the maturation enzymes. Altogether, our study provides detailed molecular insight into RNA-transcript processing and tRNA maturation in human mitochondria.\ua9 The Author(s) 2024.Mitochondrial tRNAs are less structurally stable than nuclear tRNAs, and their maturation pathway is unique. Here, the authors reveal how human mitochondrial precursor tRNAs are recognised, processed, methylated and prepared for full functionality in mitochondrial translation

    DNA structures from phosphate chemical shifts

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    For B-DNA, the strong linear correlation observed by nuclear magnetic resonance (NMR) between the 31P chemical shifts (δP) and three recurrent internucleotide distances demonstrates the tight coupling between phosphate motions and helicoidal parameters. It allows to translate δP into distance restraints directly exploitable in structural refinement. It even provides a new method for refining DNA oligomers with restraints exclusively inferred from δP. Combined with molecular dynamics in explicit solvent, these restraints lead to a structural and dynamical view of the DNA as detailed as that obtained with conventional and more extensive restraints. Tests with the Jun-Fos oligomer show that this δP-based strategy can provide a simple and straightforward method to capture DNA properties in solution, from routine NMR experiments on unlabeled samples

    The structure of the human tRNALys3 anticodon bound to the HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs

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    Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNALys3, to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3′-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5′-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNALys3. The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s2U34, and pseudouridine, Ψ39, appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U162•Ψ39 and G163•A38, that maintained a reasonable A-form helix diameter. The tRNA's s2U34 stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's Ψ39 stabilized the adjacent mismatched pairs
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