60 research outputs found

    Odorant binding proteins : a biotechnological tool for odour control

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    The application of an odorant binding protein for odour control and fragrance delayed release from a textile surface was first explored in this work. Pig OBP-1 gene was cloned and expressed in Escherichia coli , and the purified protein was biochemically characterized. The IC50 values(concentrations of competitor that caused a decay of fluorescence to half-maximal intensity) were determined for four distinct fragrances, namely, citronellol, benzyl benzoate,citronellyl valerate and ethyl valerate. The results showed a strong binding of citronellyl valerate,citronellol and benzyl benzoate to the recombinant protein, while ethyl valerate displayed weaker binding. Cationized cotton substrates were coated with porcine odorant binding protein and tested for their capacity to retain citronellol and to mask the smell of cigarette smoke. The immobilized protein delayed the release of citronellol when compared to the untreated cotton. According to a blind evaluation of 30 assessors, the smell of cigarette smoke, trapped onto the fabrics’ surface, was successfully attenuated by porcine odorant binding protein (more than 60 % identified the weakest smell intensity after protein exposure compared to β-cyclodextrin-treated and untreated cotton fabrics). This work demonstrated that porcine odorant binding protein can be an efficient solution to prevent and/orremove unpleasant odours trapped on the large surface of textiles. Its intrinsic properties make odorant binding proteins excellent candidates for controlled release systems which constitute a new application for this class of proteins.This work was co-funded by the European Social Fund through the management authority POPH and FCT. The authors Carla Silva and Teresa Matama would like to acknowledge their post-doctoral fellowships: SFRH/BPD/46515/2008 and SFRH/BPD/47555/2008, respectively

    A multi-scale analysis of bull sperm methylome revealed both species peculiarities and conserved tissue-specific

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    peer-reviewedBackground: Spermatozoa have a remarkable epigenome in line with their degree of specialization, their unique nature and different requirements for successful fertilization. Accordingly, perturbations in the establishment of DNA methylation patterns during male germ cell differentiation have been associated with infertility in several species.Background: Spermatozoa have a remarkable epigenResults: The quantification of DNA methylation at CCGG sites using luminometric methylation assay (LUMA) highlighted the undermethylation of bull sperm compared to the sperm of rams, stallions, mice, goats and men. Total blood cells displayed a similarly high level of methylation in bulls and rams, suggesting that undermethylation of the bovine genome was specific to sperm. Annotation of CCGG sites in different species revealed no striking bias in the distribution of genome features targeted by LUMA that could explain undermethylation of bull sperm. To map DNA methylation at a genome-wide scale, bull sperm was compared with bovine liver, fibroblasts and monocytes using reduced representation bisulfite sequencing (RRBS) and immunoprecipitation of methylated DNA followed by microarray hybridization (MeDIP-chip). These two methods exhibited differences in terms of genome coverage, and consistently, two independent sets of sequences differentially methylated in sperm and somatic cells were identified for RRBS and MeDIP-chip. Remarkably, in the two sets most of the differentially methylated sequences were hypomethylated in sperm. In agreement with previous studies in other species, the sequences that were specifically hypomethylated in bull sperm targeted processes relevant to the germline differentiation program (piRNA metabolism, meiosis, spermatogenesis) and sperm functions (cell adhesion, fertilization), as well as satellites and rDNA repeats. Conclusions: These results highlight the undermethylation of bull spermatozoa when compared with both bovine somatic cells and the sperm of other mammals, and raise questions regarding the dynamics of DNA methylation in bovine male germline. Whether sperm undermethylation has potential interactions with structural variation in the cattle genome may deserve further attention. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bull spermatozoa is still scarce. The purpose of this study was therefore to characterize the bull sperm methylome relative to both bovine somatic cells and the sperm of other mammals through a multiscale analysis

    Olfactory Receptors in Non-Chemosensory Organs: The Nervous System in Health and Disease

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    Olfactory receptors (ORs) and down-stream functional signaling molecules adenylyl cyclase 3 (AC3), olfactory G protein \u3b1 subunit (G\u3b1olf), OR transporters receptor transporter proteins 1 and 2 (RTP1 and RTP2), receptor expression enhancing protein 1 (REEP1), and UDP-glucuronosyltransferases (UGTs) are expressed in neurons of the human and murine central nervous system (CNS). In vitro studies have shown that these receptors react to external stimuli and therefore are equipped to be functional. However, ORs are not directly related to the detection of odors. Several molecules delivered from the blood, cerebrospinal fluid, neighboring local neurons and glial cells, distant cells through the extracellular space, and the cells' own self-regulating internal homeostasis can be postulated as possible ligands. Moreover, a single neuron outside the olfactory epithelium expresses more than one receptor, and the mechanism of transcriptional regulation may be different in olfactory epithelia and brain neurons. OR gene expression is altered in several neurodegenerative diseases including Parkinson's disease (PD), Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2 with disease-, region- and subtype-specific patterns. Altered gene expression is also observed in the prefrontal cortex in schizophrenia with a major but not total influence of chlorpromazine treatment. Preliminary parallel observations have also shown the presence of taste receptors (TASRs), mainly of the bitter taste family, in the mammalian brain, whose function is not related to taste. TASRs in brain are also abnormally regulated in neurodegenerative diseases. These seminal observations point to the need for further studies on ORs and TASRs chemoreceptors in the mammalian brain

    Le rôle des pratiques agricoles sur le contrôle biologique du blé d'hiver dans les paysages du sud de Ille et Vilaine

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    Document pas finiil s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATIONMaitriseabsen

    Estrus detection in cow

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    L’œstrus (ou chaleurs) est une période critique dans la mise en place des processus de reproduction au sein des élevages. Or, les techniques de détection actuelles s’avèrent lourdes à mettre en place, onéreuses et n’assurent pas une détection systématique de l’œstrus. Le mâle est capable de détecter l’œstrus par l’intermédiaire de signaux chimiques émis dans les urines de femelle. La connaissance de ces signaux, ainsi que de leurs protéines de liaison dans les tissus olfactifs devrait permettre le développement d’un biosenseur, permettant de détecter de façon automatique et précise les composés volatils émis par les femelles en œstrus. Afin de mettre en évidence les signaux chimiques de l’œstrus chez les bovins (Bos Taurus), des urines de vaches (30) ont été collectées à différents stades de leur cycle œstral. La composition chimique de ces urines a été déterminée par chromatographie en phase gazeuse couplée à la spectrométrie de masse. La comparaison des profils chimiques urinaires au cours de cycle œstral a permis l’identification d’une série de composés présents de façon spécifique aux stades pré-œstrus et/ou œstrus chez certains animaux. Une grande variabilité interindividuelle et entre les collectes a été observée. Aucune protéine impliquée dans la liaison des composés œstrus-spécifiques identifiés n’a pu être mise en évidence dans les urines des femelles émettrices. Chez l’animal détecteur, plusieurs isoformes de la protéine bovine de liaison aux odeurs (OBPb) ont pu être mises en évidence dans les tissus olfactifs. Des études biochimiques ont confirmé la phosphorylation d’un des variants de l’OBPb et la présence d’une chaîne N-glycannique sur la partie N-terminale de la protéine. L’existence d’une diversité d’OBPb suggère une spécificité de liaison de chaque isoforme vis-à-vis des ligands odorants. Leur propriété de liaison a été quantifiée par spectroscopie de fluorescence, ouvrant ainsi la voie à des études de relations structure-fonction de ces OBP.Estrus detection is the critical stage in livestock reproduction. Efficiency of artificial insemination, the major method of reproduction used in cattle, depends on the accurate detection of this short female stage. Currently used detection methods are quite expensive and insecure. This work aims to the elucidation of chemical communication involved in estrus detection by the male. Indeed, male can detect heats by olfactory cues emitted in urine of female. Identification of such chemical cues and their associated binding proteins in estrus behaviour will permit to develop new biotechnological tools as biosensors for estrus detection. To characterize estrus specific molecules, urine from 30 cows was collected at specific stages of the estrus cycle and their chemical composition has been assayed by GC/MS analysis. No systematic estrus specific compounds have been characterized, but we were able to characterize a few compounds as pre-estrus and/or estrus specific in some animals. Identified compounds remain to be tested for their biological activity and ability to elicit sexual behaviour to confirm their implication in estrus detection. No protein binding these molecules could be identified in urine. The urinary serum albumin, described in female elephant urine as a pheromone carrier protein, was characterized. The study of protein in the olfactory area led us to identify several isoforms of bovine Odorant Binding Protein (bOBP), in male and female olfactory tissues. Isoforms can be distinguished by their post-translational modifications. Biochemical experiments showed phosphorylation on one bOBP variant and a N-glycan is present at the N-terminus of the protein. Existence of various bOBP isoforms suggests function specificity, in particular in their binding properties. Spectroscopic fluorescence experiments were performed to analyze the structure-function relationships between the various bOBP isoforms and odorant molecules to ascertain this hypothesis

    Estrus detection in cow

    No full text
    L’œstrus (ou chaleurs) est une période critique dans la mise en place des processus de reproduction au sein des élevages. Or, les techniques de détection actuelles s’avèrent lourdes à mettre en place, onéreuses et n’assurent pas une détection systématique de l’œstrus. Le mâle est capable de détecter l’œstrus par l’intermédiaire de signaux chimiques émis dans les urines de femelle. La connaissance de ces signaux, ainsi que de leurs protéines de liaison dans les tissus olfactifs devrait permettre le développement d’un biosenseur, permettant de détecter de façon automatique et précise les composés volatils émis par les femelles en œstrus. Afin de mettre en évidence les signaux chimiques de l’œstrus chez les bovins (Bos Taurus), des urines de vaches (30) ont été collectées à différents stades de leur cycle œstral. La composition chimique de ces urines a été déterminée par chromatographie en phase gazeuse couplée à la spectrométrie de masse. La comparaison des profils chimiques urinaires au cours de cycle œstral a permis l’identification d’une série de composés présents de façon spécifique aux stades pré-œstrus et/ou œstrus chez certains animaux. Une grande variabilité interindividuelle et entre les collectes a été observée. Aucune protéine impliquée dans la liaison des composés œstrus-spécifiques identifiés n’a pu être mise en évidence dans les urines des femelles émettrices. Chez l’animal détecteur, plusieurs isoformes de la protéine bovine de liaison aux odeurs (OBPb) ont pu être mises en évidence dans les tissus olfactifs. Des études biochimiques ont confirmé la phosphorylation d’un des variants de l’OBPb et la présence d’une chaîne N-glycannique sur la partie N-terminale de la protéine. L’existence d’une diversité d’OBPb suggère une spécificité de liaison de chaque isoforme vis-à-vis des ligands odorants. Leur propriété de liaison a été quantifiée par spectroscopie de fluorescence, ouvrant ainsi la voie à des études de relations structure-fonction de ces OBP.Estrus detection is the critical stage in livestock reproduction. Efficiency of artificial insemination, the major method of reproduction used in cattle, depends on the accurate detection of this short female stage. Currently used detection methods are quite expensive and insecure. This work aims to the elucidation of chemical communication involved in estrus detection by the male. Indeed, male can detect heats by olfactory cues emitted in urine of female. Identification of such chemical cues and their associated binding proteins in estrus behaviour will permit to develop new biotechnological tools as biosensors for estrus detection. To characterize estrus specific molecules, urine from 30 cows was collected at specific stages of the estrus cycle and their chemical composition has been assayed by GC/MS analysis. No systematic estrus specific compounds have been characterized, but we were able to characterize a few compounds as pre-estrus and/or estrus specific in some animals. Identified compounds remain to be tested for their biological activity and ability to elicit sexual behaviour to confirm their implication in estrus detection. No protein binding these molecules could be identified in urine. The urinary serum albumin, described in female elephant urine as a pheromone carrier protein, was characterized. The study of protein in the olfactory area led us to identify several isoforms of bovine Odorant Binding Protein (bOBP), in male and female olfactory tissues. Isoforms can be distinguished by their post-translational modifications. Biochemical experiments showed phosphorylation on one bOBP variant and a N-glycan is present at the N-terminus of the protein. Existence of various bOBP isoforms suggests function specificity, in particular in their binding properties. Spectroscopic fluorescence experiments were performed to analyze the structure-function relationships between the various bOBP isoforms and odorant molecules to ascertain this hypothesis

    La mélatonine

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    La mélatonine est une hormone naturelle, secrétée par la glande pinéale selon un rythme circadien qui traduit l'alternance jour/nuit. Elle participe directement au fonctionnement de notre horloge biologique interne, système permettant l'adaptation de nos fonctions organiques aux variations de l'environnement. La mélatonine exercerait ses effets physiologiques par l'intermédiaire de récepteurs spécifiques MT1 et MT2, dont la connaissance paraît être la clé du mode d'action de l'hormone. Des études de structure-activité ont mené à la découverte d'analogues qui pourrait éventuellement être utilisés en thérapeutique à l'avenir. A ce jour, les propriétés attribuées à la mélatonine sont très variées : elle semblerait être efficace dans le traitement des troubles du sommeil, et en particulier dans le jet-lag, mais elle aurait également des proriétés anti-cancéreuse, antioxydante, antidépressive et même antivieillissement... Aussi, elle est parfois décrite comme la "pillule miracle", ce qui lui a ouvert un marché immense. Dans la majorité des pays européens, la mélatonine est considéré comme un médicament, mais n'a à ce jour jamais reçu d'AMM du fait que les études réalisées ne sont pas assez poussées et souvent contradictoires et que l'innocuité long terme de l'hormone n'est pas établie. Par contre, les Etats-Unis la considèrent comme un complément nutritionnel et on la trouve facilement en vente libre ou sur le réseau internet.NANCY1-SCD Pharmacie-Odontologie (543952101) / SudocSudocFranceF

    Contribution aux méthodes d'intégration des systèmes antennaires embarqués (Optimisation et validation des performances radiofréquences et CEM au moyen d'une base champ proche sphérique véhicule)

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    L objet principal de cette thèse est de déterminer les méthodes et processus innovants, dans le domaine de l intégration des systèmes antennaires, basés sur une exploitation optimale de la de la Base Champ Proche Sphérique véhicule (BCPS). Dans un premier temps, nous consacrons nos travaux à l étude et à la recherche d exploitation des techniques champs proches sphériques pour la mesure d antennes in-situ. La deuxième partie développe les travaux que nous avons menés et les résultats obtenus dans le domaine de l intégration des systèmes de réception FM à bord d un véhicule. L approche originale réside dans l association des performances intrinsèques du dispositif rayonnant sur véhicule avec l environnement électromagnétique dédié de la radiocommunication. Enfin, la troisième partie de nos travaux concerne les différentes propositions d exploitation originale de l outil BCPS en vue de l étude de sensibilité à des sources radioélectriques.The main object of this thesis is to determine the methods and innovating processes, in the domain of the antenna system integration, based on an optimal exploitation of a vehicle Spherical Near-Field Facility (SNFF). First of all, we focus our works on the study and the utilization research of spherical near-field techniques for in-situ antennas measurements. The second part is devoted to the works that we have realized and the obtained results in the field of FM broadcasting service. We propose some new evaluation methods of FM systems on board in end-using conditions. The original approach is based on the association of the intrinsic performances of the radiating element on vehicle with the final mobile communication environment. Finally, the third part of our works concerns the different propositions of original utilization of the SNFF tool for the study of the sensitivity at radio-electrical sources.RENNES-INSA (352382210) / SudocSudocFranceF

    Identification of potential chemosignals in the European water vole Arvicola terrestris

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    The water vole Arvicola terrestris is endemic to Europe where its outbreak generates severe economic losses for farmers. Our project aimed at characterising putative chemical signals used by this species, to develop new sustainable methods for population control that could also be used for this species protection in Great Britain. The water vole, as well as other rodents, uses specific urination sites as territorial and sex pheromone markers, still unidentified. Lateral scent glands and urine samples were collected from wild males and females caught in the field, at different periods of the year. Their volatile composition was analysed for each individual and not on pooled samples, revealing a specific profile of flank glands in October and a specific profile of urinary volatiles in July. The urinary protein content appeared more contrasted as males secrete higher levels of a lipocalin than females, whenever the trapping period. We named this protein arvicolin. Male and female liver transcript sequencing did not identify any expression of other odorant-binding protein sequence. This work demonstrates that even in absence of genome, identification of chemical signals from wild animals is possible and could be helpful in strategies of species control and protection
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