The evolutionary history of the SAL1 gene family in eutherian mammals

<p>Abstract</p> <p>Background</p> <p>SAL1 (salivary lipocalin) is a member of the OBP (Odorant Binding Protein) family and is involved in chemical sexual communication in pig. SAL1 and its relatives may be involved in pheromone and olfactory receptor binding and in pre-mating behaviour. The evolutionary history and the selective pressures acting on SAL1 and its orthologous genes have not yet been exhaustively described. The aim of the present work was to study the evolution of these genes, to elucidate the role of selective pressures in their evolution and the consequences for their functions.</p> <p>Results</p> <p>Here, we present the evolutionary history of SAL1 gene and its orthologous genes in mammals. We found that (1) SAL1 and its related genes arose in eutherian mammals with lineage-specific duplications in rodents, horse and cow and are lost in human, mouse lemur, bushbaby and orangutan, (2) the evolution of duplicated genes of horse, rat, mouse and guinea pig is driven by concerted evolution with extensive gene conversion events in mouse and guinea pig and by positive selection mainly acting on paralogous genes in horse and guinea pig, (3) positive selection was detected for amino acids involved in pheromone binding and amino acids putatively involved in olfactory receptor binding, (4) positive selection was also found for lineage, indicating a species-specific strategy for amino acid selection.</p> <p>Conclusions</p> <p>This work provides new insights into the evolutionary history of SAL1 and its orthologs. On one hand, some genes are subject to concerted evolution and to an increase in dosage, suggesting the need for homogeneity of sequence and function in certain species. On the other hand, positive selection plays a role in the diversification of the functions of the family and in lineage, suggesting adaptive evolution, with possible consequences for speciation and for the reinforcement of prezygotic barriers.</p

Design of a hydraulic riveter

Thesis (B.S.)--University of Illinois, 1910

Inflammation interferes with chemoreception in pigs by altering the neuronal layout of the vomeronasal sensory epithelium

Chemical communication is widely used by animals to exchange information in their environment, through the emission and detection of semiochemicals to maintain social organization and hierarchical rules in groups. The vomeronasal organ (VNO) is one of the main detectors of these messages, and its inflammation has been linked to behavioral changes because it potentially prevents molecule detection and, consequently, the translation of the signal into action. Our previous study highlighted the link between the intensity of vomeronasal sensory epithelium (VNSE) inflammation, probably induced by farm contaminant exposure, and intraspecific aggression in pigs. The aim of this study was to evaluate the cellular and molecular changes that occur during vomeronasalitis in 76 vomeronasal sensorial epithelia from 38 intensive-farmed pigs. Histology was used to evaluate the condition of each VNO and classify inflammation as healthy, weak, moderate, or strong. These data were compared to the thickness of the sensorial epithelium and the number of type 1 vomeronasal receptor cells using anti-Gαi2 protein immunohistochemistry (IHC) and analysis. The presence of odorant-binding proteins (OBPs) in the areas surrounding the VNO was also analyzed by IHC and compared to inflammation intensity since its role as a molecule transporter to sensory neurons has been well-established. Of the 76 samples, 13 (17%) were healthy, 31 (41%) presented with weak inflammation, and 32 (42%) presented with moderate inflammation. No severe inflammation was observed. Epithelial thickness and the number of Gαi2+ cells were inversely correlated with inflammation intensity (Kruskal-Wallis and ANOVA tests, p < 0.0001), while OBP expression in areas around the VNO was increased in inflamed VNO (Kruskal-Wallis test, p = 0.0094), regardless of intensity. This study showed that inflammation was associated with a reduction in the thickness of the sensory epithelium and Gαi2+ cell number, suggesting that this condition can induce different degrees of neuronal loss. This finding could explain how vomeronasalitis may prevent the correct functioning of chemical communication, leading to social conflict with a potential negative impact on welfare, which is one of the most important challenges in pig farming

Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis

<p>Abstract</p> <p>Background</p> <p>In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS) after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized <it>Hm</it>C1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR), which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of <it>Hm</it>C1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand.</p> <p>Methods</p> <p>Recombinant <it>Hm</it>C1q (r<it>Hm</it>C1q) was produced in the yeast <it>Pichia pastoris</it>. Chemotaxis assays were performed to investigate r<it>Hm</it>C1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and <it>in situ </it>hybridization techniques.</p> <p>Results</p> <p>r<it>Hm</it>C1q-stimulated microglia migrate in a dose-dependent manner. This r<it>Hm</it>C1q-induced chemotaxis was reduced when cells were preincubated with either anti-<it>Hm</it>C1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia.</p> <p>Conclusions</p> <p>A previous study showed that recruitment of microglia is observed after <it>Hm</it>C1q release at the cut end of axons. Here, we demonstrate that r<it>Hm</it>C1q-dependent chemotaxis might be driven via a <it>Hm</it>C1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal leech.</p

Le rôle des protéines liant les odeurs (odorant-binding proteins, OBP) dans la reconnaissance des signaux semiochimiques

*INRA centre de Versailles (FRA) Diffusion du document : INRA centre de Versailles (FRA

Caractérisation de protéines liant des composés à effet apaisant chez le porc

L'olfaction est une modalité sensorielle qui peut être utilisée pour réduire le stress engendré par les conditions d'élevage en porcheries industrielles. Pour comprendre le mécanisme de codage, nous avons utilisé des composés apaisants(acides gras et stéroïdes)comme sondes, pour rechercher leurs protéines olfactives de liaison au sein des trois types de muqueuses olfactives. Quatre lipocalines, possédant toutes des propriétés de liaison différentes pour les composés apaisants, ont été identifiées et caractérisées. L'implication des odeurs maternelles dans le comportement d'apaisement a conduit à l'étude des continuités odorante et protéique trans-natale. Les trois protéines majeures de l'aire olfactive ont été sur-exprimées en cellules de levure Pichia pastoris et soumises à divers tests de liaisons avec les composés apaisants. Ce travail démontre le rôle fondamental de premier filtre sélectif que jouent les protéines olfactives dans la détection de signaux apaisants.TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

Characterization of putative OBP/PBP in the bee

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Rôle des odorants-binding protein dans le mécanisme de transduction olfactive (implication de modifications post-traductionnelles dynamiques dans la spécificité de liaison avec les ligands)

Les OBP sont des petites protéines solubles qui se lient avec des molécules odorantes et phéromonales. Le rôle des OBPs n est pas complètement compris. Une hypothèse suggère que l OBP solubilise et transporte les ligands aux récepteurs olfactifs et la liaison entre les molécules odorantes et l OBP est non spécifique. Une autre hypothèse suggère que le complexe formé est une liaison spécifique entre une molécule odorante donnée et une OBP spécifique. Ce travail de thèse montre que les OBPs sont impliquées dans la première étape de la discrimination des odeurs. Dans un premier temps, nous avons montré l implication de la Phe35 et la Tyr 82 dans la sortie du ligand par l OBP. Dans un second temps, nous avons mis en évidence la présence de différentes isoformes d OBP et de VEG qui diffèrent par les modifications post-traductionnelles (phosphorylation et GlcNAcylation) a la fois sur les protéines natives extraites de la muqueuse respiratoire et sur les protéines recombinantes produites par P.pastoris et CHO. Ces isoformes sont capables de discriminer des molécules odorantes et phéromonales. Les OBPs ne sont pas des transporteurs passifs car elles assurent un fin codage des molécules odorantes ou phéromonales avant l interaction de ce complexe avec un récepteur spécifique.OBPs are small soluble proteins that bind with odorant molecules and pheromones. The role of OBP is not completely understood. A hypothesis suggests that OBP solubilize and transport the ligands to olfactory receptors and the binding between odorant molecule and OBP is unspecific. An other hypothesis suggest that the complex formed is the specific binding between a given odorant molecule and a specific OBP. This work of thesis show that OBP are involved in the first step of odorant discrimination. Initially, we have showed the involvement of the Phe35 and Tyr 82 in the uptake of ligands by OBP. Second, we have given rise to the presence of various isoform of OBP and VEG that differ by post-translational modifications (phosphorylation and GlcNAcylation) both on natives proteins extract of respiratory mucosa and on recombinants proteins produce by P. pastoris and CHO. These isoforms are able to discriminate of odorant molecules and pheromones. OBPs are not passives carriers because they ensure a fine coding of odorant molecules and pheromones before interaction of this complex with specific receptor.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

MALDI-TOFMS identification of "odorant binding proteins" (OBPs) electroblotted onto poly(vinylidence difluoride) membranes

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Evidence for OBP and PBP isoforms in Mamestra brassicae antennae

*INRA, centre de Versailles Diffusion du document : INRA, centre de VersaillesInternational audienc