Réalisation d'une bibliothèque C de fonctions ondelettes

Ce rapport s'adresse aux personnes désireuses de connaitre la théorie des ondelettes sans être de pures mathématiciens. Il décrit la théorie des ondelettes tout en mettant l'accent sur les différents types d'ondelettes et leurs propriétés respectives ainsi que les transformées ondelettes. Une librairie, appelée WaveLib, décrite dans ce rapport permet à l'utilisateur la manipulation et l'utilisation des ondelettes et leurs transformées de manière transparente. Des exemples d'utilisation sont donnés afin de montrer la simplicité d'utilisation de cette librairie

Construction of plant transformation vectors carrying beet necrotic yellow vein virus coat protein gene (ii)- plant transformation

Fragments containing the coat protein gene of beet necrotic yellow vein virus were cloned in two plant transformation vectors: pCAMBIA3301M with the bar gene as selectable marker, and pCAMBIA1304M, with resistance to hygromycin. Three constructs were made of each vector: CPL, containing coat protein gene with leader sequence; CPS with coat protein gene, and CPSas with coat protein gene in antisense orientation. Vectors pC3301MCPL, pC3301MCPS. and pC3301MCPSas were used in Agrobacterium—mediated transformation of Nicotiana tabacum (tobacco), Nicotiana excelsior and Nicotiana benthamiana. Regenerants that developed roots on selective media were tested for the presence of CP fragments and the bar gene, but most regenerants were nontransformed (50-83% escapes). After all rooted plants had been selfed, and T1 seed germinated on selective media, only plants descending from one N. excelsior regenerant transformed with pC3301MCPS were positive for presence of bar gene and CPS fragment. Tobacco and Nicotiana benthamiana were transformed with constructs pC1304MCPS and pC1304MCPSas. Transformation efficiency was much higher and approximately 50% of regenerants that rooted on media with 20 mg l−1 hygromycin were positive for the presence of CP fragments. All T1 plants were positive for presence of CP fragments

A comparison of three different delivery methods for achieving CRISPR/Cas9 mediated genome editing in Cichorium intybus L.

Root chicory (Cichorium intybus L. var. sativum) is used to extract inulin, a fructose polymer used as a natural sweetener and prebiotic. However, bitter tasting sesquiterpene lactones, giving chicory its known flavour, need to be removed during inulin extraction. To avoid this extraction and associated costs, recently chicory variants with a lower sesquiterpene lactone content were created by inactivating the four copies of the germacrene A synthase gene (CiGAS-S1, -S2, -S3, -L) which encode the enzyme initiating bitter sesquiterpene lactone biosynthesis in chicory. In this study, different delivery methods for CRISPR/Cas9 reagents have been compared regarding their efficiency to induce mutations in the CiGAS genes, the frequency of off-target mutations as well as their environmental and economic impacts. CRISPR/Cas9 reagents were delivered by Agrobacterium-mediated stable transformation or transient delivery by plasmid or preassembled ribonucleic complexes (RNPs) using the same sgRNA. All methods used lead to a high number of INDEL mutations within the CiGAS-S1 and CiGAS-S2 genes, which match the used sgRNA perfectly; additionally, the CiGAS-S3 and CiGAS-L genes, which have a single mismatch with the sgRNA, were mutated but with a lower mutation efficiency. While using both RNPs and plasmids delivery resulted in biallelic, heterozygous or homozygous mutations, plasmid delivery resulted in 30% of unwanted integration of plasmid fragments in the genome. Plants transformed via Agrobacteria often showed chimerism and a mixture of CiGAS genotypes. This genetic mosaic becomes more diverse when plants were grown over a prolonged period. While the genotype of the on-targets varied between the transient and stable delivery methods, no off-target activity in six identified potential off-targets with two to four mismatches was found. The environmental impacts (greenhouse gas (GHG) emissions and primary energy demand) of the methods are highly dependent on their individual electricity demand. From an economic view - like for most research and development activities - employment and value-added multiplier effects are high; particularly when compared to industrial or manufacturing processes. Considering all aspects, we conclude that using RNPs is the most suitable method for genome editing in chicory since it led to a high efficiency of editing, no off-target mutations, non-transgenic plants with no risk of unwanted integration of plasmid DNA and without needed segregation of transgenes

Functional Characterization of FLT3 Receptor Signaling Deregulation in Acute Myeloid Leukemia by Single Cell Network Profiling (SCNP)

Molecular characterization of the FMS-like tyrosine kinase 3 receptor (FLT3) in cytogenetically normal acute myeloid leukemia (AML) has recently been incorporated into clinical guidelines based on correlations between FLT3 internal tandem duplications (FLT3-ITD) and decreased disease-free and overall survival. These mutations result in constitutive activation of FLT3, and FLT3 inhibitors are currently undergoing trials in AML patients selected on FLT3 molecular status. However, the transient and partial responses observed suggest that FLT3 mutational status alone does not provide complete information on FLT3 biological activity at the individual patient level. Examination of variation in cellular responsiveness to signaling modulation may be more informative.Using single cell network profiling (SCNP), cells were treated with extracellular modulators and their functional responses were quantified by multiparametric flow cytometry. Intracellular signaling responses were compared between healthy bone marrow myeloblasts (BMMb) and AML leukemic blasts characterized as FLT3 wild type (FLT3-WT) or FLT3-ITD. Compared to healthy BMMb, FLT3-WT leukemic blasts demonstrated a wide range of signaling responses to FLT3 ligand (FLT3L), including elevated and sustained PI3K and Ras/Raf/Erk signaling. Distinct signaling and apoptosis profiles were observed in FLT3-WT and FLT3-ITD AML samples, with more uniform signaling observed in FLT3-ITD AML samples. Specifically, increased basal p-Stat5 levels, decreased FLT3L induced activation of the PI3K and Ras/Raf/Erk pathways, decreased IL-27 induced activation of the Jak/Stat pathway, and heightened apoptotic responses to agents inducing DNA damage were observed in FLT3-ITD AML samples. Preliminary analysis correlating these findings with clinical outcomes suggests that classification of patient samples based on signaling profiles may more accurately reflect FLT3 signaling deregulation and provide additional information for disease characterization and management.These studies show the feasibility of SCNP to assess modulated intracellular signaling pathways and characterize the biology of individual AML samples in the context of genetic alterations

Fructan and its relationship to abiotic stress tolerance in plants

Numerous studies have been published that attempted to correlate fructan concentrations with freezing and drought tolerance. Studies investigating the effect of fructan on liposomes indicated that a direct interaction between membranes and fructan was possible. This new area of research began to move fructan and its association with stress beyond mere correlation by confirming that fructan has the capacity to stabilize membranes during drying by inserting at least part of the polysaccharide into the lipid headgroup region of the membrane. This helps prevent leakage when water is removed from the system either during freezing or drought. When plants were transformed with the ability to synthesize fructan, a concomitant increase in drought and/or freezing tolerance was confirmed. These experiments indicate that besides an indirect effect of supplying tissues with hexose sugars, fructan has a direct protective effect that can be demonstrated by both model systems and genetic transformation

Détermination par l'électrophorèse capillaire, méthode CIA, des anions minéraux et des cations majeurs. Comparaison avec différentes méthodes

National audienc

Combining soil anaerobic microbial activities with geochemical reactions : model and experiments

International audienc

Nitrous oxide emission : a comparison of field measurements and model predictions

National audienc