Precise detection of rearrangement breakpoints in mammalian chromosomes

<p>Abstract</p> <p>Background</p> <p>Genomes undergo large structural changes that alter their organisation. The chromosomal regions affected by these rearrangements are called breakpoints, while those which have not been rearranged are called synteny blocks. We developed a method to precisely delimit rearrangement breakpoints on a genome by comparison with the genome of a related species. Contrary to current methods which search for synteny blocks and simply return what remains in the genome as breakpoints, we propose to go further and to investigate the breakpoints themselves in order to refine them.</p> <p>Results</p> <p>Given some reliable and non overlapping synteny blocks, the core of the method consists in refining the regions that are not contained in them. By aligning each breakpoint sequence against its specific orthologous sequences in the other species, we can look for weak similarities inside the breakpoint, thus extending the synteny blocks and narrowing the breakpoints. The identification of the narrowed breakpoints relies on a segmentation algorithm and is statistically assessed. Since this method requires as input synteny blocks with some properties which, though they appear natural, are not verified by current methods for detecting such blocks, we further give a formal definition and provide an algorithm to compute them.</p> <p>The whole method is applied to delimit breakpoints on the human genome when compared to the mouse and dog genomes. Among the 355 human-mouse and 240 human-dog breakpoints, 168 and 146 respectively span less than 50 Kb. We compared the resulting breakpoints with some publicly available ones and show that we achieve a better resolution. Furthermore, we suggest that breakpoints are rarely reduced to a point, and instead consist in often large regions that can be distinguished from the sequences around in terms of segmental duplications, similarity with related species, and transposable elements.</p> <p>Conclusion</p> <p>Our method leads to smaller breakpoints than already published ones and allows for a better description of their internal structure. In the majority of cases, our refined regions of breakpoint exhibit specific biological properties (no similarity, presence of segmental duplications and of transposable elements). We hope that this new result may provide some insight into the mechanism and evolutionary properties of chromosomal rearrangements.</p

Potential therapeutic applications of microbial surface-activecompounds

Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

Copper Mineralization in Adoudounian Cover of the Bou Azzer-El Graara (Anti Atlas, Morocco): Tectono-Stratigraphic Controls

International audienceCopper mineralization in sedimentary cover is well known in association with Pb and/or Zn in Sedex, Kupferschiefer, Mississippi Valley-Type, or Red bed deposits. In spite of great economic potential, the syngenetic versus epigenetic origin of widespread Cu occurrences in the Adoudounian sedimentary cover, in the Moroccan Anti Atlas, remains debated. Significant investigations that would provide critical information for mining exploration are lacking. Whatever their origin, these mineralizations do not correspond to classical sediment-hosted deposits, the ore being exclusively Cu concentrations in dolostone units. This study, based on field and microscopic observations, is focused on Cu mineralization hosted in the Adoudounian cover of the Bou Azzer-El Graara inlier. Two morphologic types of ore bodies exist. The first consists of stratabound lenses and the second type is vein networks along Variscan faults. Both types of mineralization have a stockwork texture and clearly postdate sedimentary fabrics, such as beddings and slumps; this suggests a common epigenetic origin for the both ore types. The proposed interpretation involves the upflow of Variscan fluid-driven interaction between a basement and its sedimentary cover

NO signaling in tobacco elicited by the MAMP cryptogein

SPEPôle IPMInternational audienceDuring the past years, nitric oxide (NO) has been shown to be a major cell signaling messenger in plants. Its importance has been highlighted during plant responses to pathogen attack or MAMPs (microbe associated molecular patterns) and during induced resistance or priming phenomenon. The major focus of our research is to understand how nitric oxide can modulate the activity of protein involved in plant defense. We identified several proteins undergoing S-nitrosylation, a redox-based post-translational modification of proteins, in tobacco cells elicited by cryptogein, a 10 kDa protein produced by the oomycete Phytophthora cryptogea and inducing immune responses in tobacco. These proteins include the chaperone-like AAA+-ATPase CDC48 and a calmodulin isoform. The incidence of NO on the structure and function of both proteins has been investigated. Concerning CDC48, the S-nitrosylated cystein is located in the vicinity of the ATP binding site in the second ATPase domain. Its S-nitrosylation triggers local structural changes that correlates with a strong reduction of the ATPase activity. Calmodulins are Ca2+ sensors that decode Ca2+ signals in all eukaryotes organisms. Ca2+ binds to 4 EF-hand domains inducing a conformational change of the protein. This change is required for CaM binding to target protein then modulating their activities. We showed that a recombinant CaM is S-nitrosylated on a unique cystein residue either in the presence or in the absence of Ca2+. This cystein residue is located in the first EF-hand domain suggesting a role of the S-nitrosylation in CaM function. Through the identification of new components of NO signaling, our work further supports the concept that NO is a key mediator in the signaling cascade leading to immune responses in plants

A contribution to the synsedimentary versus epigenetic origin of the Cu mineralizations hosted by terminal Neoproterozoic to Cambrian formations of the Bou Azzer–El Graara inlier: New insights from the Jbel Laassel deposit (Anti Atlas, Morocco)

International audienceThe Neoproterozoic to Cambrian formations that compose the cover of the Bou Azzer–El Graara inlier, host a great number of Copper occurrence whose origin is largely discussed. To bring some light to this debate, structural, petrographic and geochemical observations were performed on the copper deposit of Jbel Laassel. This deposit, located at the extreme ESE of the Bou Azzer–El Graara inlier, is mined since 2012. At the district scale, the ore bodies localize in a folding band that extends along a NE–SW direction. At macroscopic, microscopic and scanning electron microscope scales the mineralization appears as banding veins, with locally cockade breccia and comb quartz textures. From the macroscopic scale to the scale of the scanning electron microscope, all these mineralized textures are connected there between forming a stockwork with an auto-similar structure in the range of used scales of observation. At the district scale, this stockwork is preferentially located in the anticlinal hinges of the folding band. Principal component analyses of geochemical database enable to distinguish several groups of chemical elements, each of these groups corresponding to the different lithologies and to the copper mineralization. This last group does not show any correlation with the distinguished lithological groups. All these observations bring new arguments to an epigenetic origin for the copper mineralization of the Jbel Laassel deposit, with a formation contemporary or posterior with the folding band development attributed to Variscan deformation

The chaperone-like protein CDC48 regulates ascorbate peroxidase in tobacco

International audienceThere is increasing evidence that the chaperone-like protein CDC48 (cell division cycle 48) plays a role in plant immunity. Cytosolic ascorbate peroxidase (cAPX), which is a major regulator of the redox status of plant cells, has previously been shown to interact with CDC48. In this study, we examined the regulation of cAPX by the ATPase NtCDC48 during the cryptogein-induced immune response in tobacco cells. Our results not only confirmed the interaction between the proteins but also showed that it occurs in the cytosol. cAPX accumulation was modified in cells overexpressing NtCDC48, a process that was shown to involve post-translational modification of cAPX. In addition, cryptogein-induced increases in cAPX activity were suppressed in cells overexpressing NtCDC48 and the abundance of the cAPX dimer was below the level of detection. Furthermore, the levels of both reduced (GSH) and oxidized glutathione (GSSG) and the GSH/GSSG ratio decreased more rapidly in response to the elicitor in these cells than in controls. A decrease in cAPX activity was also observed in response to heat shock in the cells overexpressing NtCDC48, indicating that the regulation of cAPX by NtCDC48 is not specific to the immune response

Étude exploratoire : perceptions, croyances, connaissances et attitudes d’un groupe d’aînés francophones du Nouveau-Brunswick concernant la démence et son diagnostic

Cette étude explore les perceptions, croyances, connaissances et attitudes d’un groupe d’aînés francophones du Nouveau-Brunswick face à la démence et à son diagnostic; le diagnostic précoce de la démence est crucial autant pour l’identification des causes réversibles que pour la mise en place rapide d’interventions de prévention secondaire. Quatre-vingt-onze francophones du Nouveau-Brunswick âgés de 65 ans et plus ont été interrogés face à la démence et à son diagnostic dans cette étude quantitative exploratoire. Entre autres, bien que les participants de cette étude aient rapporté avoir peur de recevoir un diagnostic de démence, la plupart voudraient recevoir le diagnostic s’ils en étaient atteints. Les résultats soulignent l’importance d’éduquer la population face à la démence et aux services d’évaluation de la démence. D’autres implications sont discutées.This study explores the perceptions, beliefs, knowledge and attitudes of a group of francophone seniors from New Brunswick in regards to dementia and its diagnosis; the early diagnosis of dementia is crucial both for the identification of reversible causes and the timely implementation of interventions for secondary prevention. Ninety-one francophone seniors from New Brunswick aged 65 and older were surveyed in regards to dementia and its diagnosis in this exploratory quantitative study. Among other things, it was found that although the participants from this study feared receiving a diagnosis of dementia, most would want to receive the diagnosis if they had dementia. Results stress the importance of educating the public regarding dementia and its evaluation services. Other implications are discussed

NO signaling in plant immunity: A tale of messengers

International audienceNitric oxide (NO) is a free radical gas involved in a myriad of plant physiological processes including immune responses. How NO mediates its biological effects in plant facing microbial pathogen attack is an unresolved question. Insights into the molecular mechanisms by which it propagates signals reveal the contribution of this simple gas in complex signaling pathways shared with reactive oxygen species (ROS) and the second messenger Ca2+. Understanding of the subtle cross-talks operating between these signals was greatly improved by the recent identification and the functional analysis of proteins regulated through S-nitrosylation, a major NO-dependent post-translational protein modification. Overall, these findings suggest that NO is probably an important component of the mechanism coordinating and regulating Ca2+ and ROS signaling in plant immunity. (C) 2014 Elsevier Ltd. All rights reserved