2,297 research outputs found
Sputnik Enterprises:
Summaries Russian scientific and technical capacities under socialism were mainly concentrated in academic research institutes. Their human and incorporated assets are now threatened by two factors: lack of resources, affected by a weakened state, and a structural disconnection from productive capacities, inherited from the socialist system in which institutes supplied their results to administrative bodies and had no direct relations with industry. Academic institutes are therefore undergoing decline or profound restructuring. A new phenomenon appears in this context: the appearance of high?technology SMEs orbiting around academic institutes. The link between these SMEs and institutes characterises a creation mode specific to post?socialism and provides a promising alternative to the institutes' decline. This analysis is based on surveys conducted by the authors in institutes and emerging SMEs in a Siberian science city
Reversible inactivation of the transcriptional function of P53 protein by farnesylation
BACKGROUND: The use of integrating viral vectors in Gene therapy clinical trials has pointed out the problem of the deleterous effect of the integration of the ectopic gene to the cellular genome and the safety of this strategy. We proposed here a way to induce the death of gene modified cells upon request by acting on a pro-apoptotic protein cellular localization and on the activation of its apoptotic function. RESULTS: We constructed an adenoviral vector coding a chimeric p53 protein by fusing p53 sequence with the 21 COOH term amino acids sequence of H-Ras. Indeed, the translation products of Ras genes are cytosolic proteins that become secondarily associated with membranes through a series of post-translational modifications initiated by a CAAX motif present at the C terminus of Ras proteins. The chimeric p53HRCaax protein was farnesylated efficiently in transduced human osteosarcoma p53-/- cell line. The farnesylated form of p53 resided mainly in the cytosol, where it is non-functional. Farnesyl transferase inhibitors (FTIs) specifically inhibited farnesyl isoprenoid lipid modification of proteins. Following treatment of the cells with an FTI, p53HRCaax underwent translocation into the nucleus where it retained transcription factor activity. Shifting p53 into the nucleus resulted in the induction of p21(waf1/CIP1 )and Bax transcription, cell growth arrest, caspase activation and apoptosis. CONCLUSION: Artificial protein farnesylation impaired the transcriptional activity of p53. This could be prevented by Farnesyl transferase inhibition. These data highlight the fact that the artificial prenylation of proteins provides a novel system for controlling the function of a transactivating factor
Pearl millet genomic vulnerability to climate change in West Africa highlights the need for regional collaboration
Climate change is already affecting agro-ecosystems and threatening food security by reducing crop productivity and increasing harvest uncertainty. Mobilizing crop diversity could be an efficient way to mitigate its impact. We test this hypothesis in pearl millet, a nutritious staple cereal cultivated in arid and low-fertility soils in sub-Saharan Africa. We analyze the genomic diversity of 173 landraces collected in West Africa together with an extensive climate dataset composed of metrics of agronomic importance. Mapping the pearl millet genomic vulnerability at the 2050 horizon based on the current genomic-climate relationships, we identify the northern edge of the current areas of cultivation of both early and late flowering varieties as being the most vulnerable to climate change. We predict that the most vulnerable areas will benefit from using landraces that already grow in equivalent climate conditions today. However, such seed-exchange scenarios will require long distance and trans-frontier assisted migrations. Leveraging genetic diversity as a climate mitigation strategy in West Africa will thus require regional collaboration
MoccaDB - an integrative database for functional, comparative and diversity studies in the Rubiaceae family
<p>Abstract</p> <p>Background</p> <p>In the past few years, functional genomics information has been rapidly accumulating on Rubiaceae species and especially on those belonging to the <it>Coffea </it>genus (coffee trees). An increasing number of expressed sequence tag (EST) data and EST- or genomic-derived microsatellite markers have been generated, together with Conserved Ortholog Set (COS) markers. This considerably facilitates comparative genomics or map-based genetic studies through the common use of orthologous loci across different species. Similar genomic information is available for e.g. tomato or potato, members of the Solanaceae family. Since both Rubiaceae and Solanaceae belong to the Euasterids I (lamiids) integration of information on genetic markers would be possible and lead to more efficient analyses and discovery of key loci involved in important traits such as fruit development, quality, and maturation, or adaptation. Our goal was to develop a comprehensive web data source for integrated information on validated orthologous markers in Rubiaceae.</p> <p>Description</p> <p>MoccaDB is an online MySQL-PHP driven relational database that houses annotated and/or mapped microsatellite markers in Rubiaceae. In its current release, the database stores 638 markers that have been defined on 259 ESTs and 379 genomic sequences. Marker information was retrieved from 11 published works, and completed with original data on 132 microsatellite markers validated in our laboratory. DNA sequences were derived from three <it>Coffea </it>species/hybrids. Microsatellite markers were checked for similarity, <it>in vitro </it>tested for cross-amplification and diversity/polymorphism status in up to 38 Rubiaceae species belonging to the Cinchonoideae and Rubioideae subfamilies. Functional annotation was provided and some markers associated with described metabolic pathways were also integrated. Users can search the database for marker, sequence, map or diversity information through multi-option query forms. The retrieved data can be browsed and downloaded, along with protocols used, using a standard web browser. MoccaDB also integrates bioinformatics tools (CMap viewer and local BLAST) and hyperlinks to related external data sources (NCBI GenBank and PubMed, SOL Genomic Network database).</p> <p>Conclusion</p> <p>We believe that MoccaDB will be extremely useful for all researchers working in the areas of comparative and functional genomics and molecular evolution, in general, and population analysis and association mapping of Rubiaceae and Solanaceae species, in particular.</p
New Genetic Insights into Pearl Millet Diversity As Revealed by Characterization of Early- and Late-Flowering Landraces from Senegal
Pearl millet (Pennisetum glaucum (L.) R. Br.) is a staple food and a drought-tolerant cereal well adapted to Sub-Saharan Africa agro-ecosystems. An important diversity of pearl millet landraces has been widely conserved by farmers and therefore could help copping with climate changes and contribute to future food security. Hence, characterizing its genetic diversity and population structure can contribute to better assist breeding programs for a sustainable agricultural productivity enhancement. Toward this goal, a comprehensive panel of 404 accessions were used that correspond to 12 improved varieties, 306 early flowering and 86 late-flowering cultivated landraces from Senegal. Twelve highly polymorphic SSR markers were used to study diversity and population structure. Two genes, PgMADS11 and PgPHYC, were genotyped to assess their association to flowering phenotypic difference in landraces. Results indicate a large diversity and untapped potential of Senegalese pearl millet germplasm as well as a genetic differentiation between early- and late-flowering landraces. Further, a fine-scale genetic difference of PgPHYC and PgMADS11 (SNP and indel, respectively) and co-variation of their alleles with flowering time were found among landraces. These findings highlight new genetic insights of pearl millet useful to define heterotic populations for breeding, genomic association panel, or crosses for trait-specific mapping
Chloroplast Sequence of Treegourd (Crescentia cujete, Bignoniaceae) to Study Phylogeography and Domestication
Premise of the study: Crescentia cujete (Bignoniaceae) fruit rinds are traditionally used for storage vessels and handicrafts. We assembled its chloroplast genome and identified single-nucleotide polymorphisms (SNPs). Methods and Results: Using a genome skimming approach, the whole chloroplast of C. cujete was assembled using 3,106,928 sequence reads of 150 bp. The chloroplast is 154,662 bp in length, structurally divided into a large single copy region (84,788 bp), a small single copy region (18,299 bp), and two inverted repeat regions (51,575 bp) with 88 genes annotated. By resequencing the whole chloroplast, we identified 66 SNPs in C. cujete (N = 30) and 68 SNPs in C. amazonica (N = 6). Nucleotide diversity was estimated at 1.1 × 10-3 and 3.5 × 10-3 for C. cujete and C. amazonica, respectively. Conclusions: This broadened C. cujete genetic toolkit will be important to study the origin, domestication, diversity, and phylogeography of treegourds in the Neotropics. © 2016 Moreira et al. Published by the Botanical Society of America
Tunable red-light source by frequency mixing from dual band Er/Yb co-doped fiber laser
International audienceWe report an all solid state laser device producing tunable dual wavelength emission in the near IR region (1060nm, and 1550 nm) by use of an Er/Yb co-doped fiber. Generation of continuous-wave radiation around 630 nm is then demonstrated by extra-cavity sum frequency mixing in a Periodically Poled Lithium Niobate (PPLN) crystal. Quasi phase matching conditions are obtained over 7 nm to generate tunable coherent light in the red spectral range
Complete exon sequencing of all known Usher syndrome genes greatly improves molecular diagnosis
<p>Abstract</p> <p>Background</p> <p>Usher syndrome (USH) combines sensorineural deafness with blindness. It is inherited in an autosomal recessive mode. Early diagnosis is critical for adapted educational and patient management choices, and for genetic counseling. To date, nine causative genes have been identified for the three clinical subtypes (USH1, USH2 and USH3). Current diagnostic strategies make use of a genotyping microarray that is based on the previously reported mutations. The purpose of this study was to design a more accurate molecular diagnosis tool.</p> <p>Methods</p> <p>We sequenced the 366 coding exons and flanking regions of the nine known USH genes, in 54 USH patients (27 USH1, 21 USH2 and 6 USH3).</p> <p>Results</p> <p>Biallelic mutations were detected in 39 patients (72%) and monoallelic mutations in an additional 10 patients (18.5%). In addition to biallelic mutations in one of the USH genes, presumably pathogenic mutations in another USH gene were detected in seven patients (13%), and another patient carried monoallelic mutations in three different USH genes. Notably, none of the USH3 patients carried detectable mutations in the only known USH3 gene, whereas they all carried mutations in USH2 genes. Most importantly, the currently used microarray would have detected only 30 of the 81 different mutations that we found, of which 39 (48%) were novel.</p> <p>Conclusions</p> <p>Based on these results, complete exon sequencing of the currently known USH genes stands as a definite improvement for molecular diagnosis of this disease, which is of utmost importance in the perspective of gene therapy.</p
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