Spelling suggestions: "subject:"gustatory"" "subject:"auscultatory""
11 |
Gustatory and olfactory feeding responces in Japanese koi carp (Cyprinus carpio)Barnard, Philip 03 1900 (has links)
Thesis (MPhil (Animal Sciences. Aquaculture))--University of Stellenbosch, 2006. / Chemo-attraction and –stimulation facilitate the initial location (olfactory response) and final consumption (gustatory response) of food in the feeding process of fish. Chemo-attractants or chemo-stimulants is therefore generally included in feeds for especially slow-feeding species to help reduce water fouling and to promote feed efficiency and growth rate through improved feed intake. Considering this, a study was performed to evaluate the attraction and stimulation potential of selected cereals and free amino acids in diets for Japanese koi carp (Cyprinus carpio). Results are presented on the comparative evaluation of five cereals (maize, sorghum, wheat, rye and triticale), raw and cooked forms of maize and concentrations of betaine and selected free amino acids (alanine, arginine, lysine and methionine), as well as their additive effect.
|
12 |
The Role of Serotonin Availability in the Rat Insular Cortex on Conditioned Disgust and Conditioned Taste AvoidanceTuerke, Katharine 18 January 2013 (has links)
Although the neural mechanisms regulating vomiting are well understood, the neurobiology of nausea is not. Unlike conditioned taste avoidance (CTA), conditioned disgust (indicated by orofacial gaping reactions) is a model of nausea-induced behaviour in rats because it is selectively produced by emetic drugs and anti-emetics attenuate it. Treatments that reduce serotonin (5-HT) availability selectively interfere with conditioned gaping (Limebeer and Parker, 2000; 2003) and forebrain serotonin is critical for the production of disgust reactions (Grill and Norgren, 1978b; Limebeer et al., 2004). The insular cortex (IC) is a site of taste-illness associations and is involved in the sensation of nausea and vomiting in humans (Penfield and Faulk, 1955; Fiol et al., 1988; Catenoix et al., 2008) and other animals (Kaada, 1951; Contreras et al., 2007). Therefore, we investigated the relationship between serotonin, conditioned gaping and CTA in the insular cortex.
Systemic pretreatment with the classic anti-emetic ondansetron (OND) reduced both LiCl-induced unconditioned malaise (assessed by lying on belly) and conditioned gaping reactions, without modifying CTA. These experiments demonstrate that decreases in serotonin availability interfere with conditioned gaping and unconditioned malaise as well as provide further evidence of the validity of the conditioned gaping model.
Rats with bilateral NMDA lesions of the agranular IC showed attenuated CTA learning but conditioned gaping reactions were unaffected. This finding suggests that the agranular IC, a site of gustatory input, may be required for CTA learning.
Partial serotonergic depletion of the IC attenuated conditioned gaping reactions, suggesting that serotonin in the IC is required to establish conditioned gaping. A double dissociation in the regulation of disgust and taste avoidance, by selective 5-HT3 receptor antagonism/agonism in the visceral (granular) IC and the gustatory (agranular) IC was observed. Infusion of OND into the visceral IC attenuated conditioned gaping but spared CTA. Additionally, administration of the 5-HT3 receptor agonist m-chlorophenylbiguanide (mCPBG) enhanced LiCl-induced conditioned gaping reactions (which was prevented by intracranial administration of OND), but spared CTA. In contrast, intracranial OND pretreatment in the gustatory IC attenuated CTA and mCPBG infusions produced CTA, but neither affected the nausea-induced behaviour of conditioned gaping.
Together, these studies shed light on the neurobiology of nausea. These results suggest that 5-HT activity (at the 5-HT3 receptor) in the visceral IC may selectively produce the nausea-induced reactions of conditioned disgust, while activity in the gustatory IC may be involved in the production of CTA learning. / This research was supported by a Natural Sciences and Engineering Research Council (NSERC) operating grant (92057) to L.A. Parker and a NSERC CGS-D scholarship to K.J. Tuerke. This work was also supported by an Ontario Graduate Scholarship to K.J. Tuerke.
|
13 |
Rôle et fonctionnalité des récepteurs gustatifs dans les ailes de drosophiles / Role and function of drosophila taste receptors in drosophila wingsRaad, Hussein 25 January 2013 (has links)
Les capacités cognitives pour assurer l’exploration et la découverte de nouvelles niches écologiques sont au cœur des processus d’adaptation et de survie des espèces vertébrés et invertébrés. A cet égard, les systèmes neuronaux chimio-sensoriels composés des organes olfactifs et gustatifs permettent le guidage et repérage des sources de nourritures et/ou des partenaires sexuels. Un fait marquant chez les insectes et en particulier la drosophile réside dans le fait que les organes gustatifs sont disséminés sur le corps. La bordure antérieure de l’aile est tapissée avec des sensilles gustatives alternées avec des sensilles mécaniques. La fonctionnalité et le rôle des cellules gustatives au niveau de l’aile de la drosophile reste énigmatique et à ce jour largement inconnue (Stocker, 1994). Notre travail a consisté à explorer la signalisation et le mécanisme de transduction de ces récepteurs et à questionner leur importance dans l’adaptation des insectes à leur écosystème. Nos résultats portent sur trois volets. Nous avons vérifié que l’expression des récepteurs du goût est effective dans les ailes des trois insectes différents (drosophiles, pucerons et abeilles) par RT-PCR. Nous avons ensuite étudié la fonctionnalité de ces récepteurs vis-à-vis des molécules sucrées et amères à l’aide d’une souche transgénique (G-CaMP), qui exhibe une forte fluorescence provoquée par des piques de calcium cytosolique. Enfin, des tests comportementaux ont été réalisé avec une souche transgénique (Poxn*) dans laquelle les sensilles chimio-sensorielles de l’aile sont spécifiquement invalidés sans altérer les autres structures olfactives et/ou gustatives. Les résultats montrent un effet significatif des cellules chimio-sensorielles de l’aile quant à l’orientation dans l’espace et à l’apprentissage Bayesien. Nos résultats sur ces trois volets nous ont permis d’élaborer des hypothèses au regard de l’évolution neuroanatomique de l’aile des insectes depuis les organismes ancestraux d’origine marine desquels ils dérivent. Des experts en aérodynamiques proposent la création d’un vortex durant le vol qui forme une spirale de courant d’air le long de la bordure antérieur de l’aile. La parfaite superposition entre ce vortex et le nerf costal de l’aile nous permet de déduire que les vibrations de l’aile entre 50 et 1.000 Hertz chez les insectes sont en mesure de nébuliser des matériaux (micro poussières, micro gouttelettes, molécules faiblement volatiles) lesquels vont être captés/entrainés dans le vortex et adressés aux sensilles gustatives. Notre hypothèse est que ce mécanisme permettrait aux insectes pollinisateurs de gouter les fleurs sans se poser et sans mettre à contribution la trompe buccale (proboscis). Ce scénario permettrait de dissocier le goût de l’ingestion digestive en évitant les empoisonnements par des molécules toxiques émises par les plantes et d’autre part il rend l’exploration plus efficace, en minimisant le temps de recherche. / Cognitive capacities used to ensure the exploration and discovery of new ecological niches are at the heart of the process of adaptation and survival of vertebrate and invertebrate species. In this respect, the neural chemosensory systems, composed of the olfactory and gustatory organs, allow the guidance and finding of food sources and/or sexual partners. A striking feature in insects and particularly in Drosophila is that gustatory organs are disseminated in the body. The anterior margin of the wing is lined with gustatory sensilla alternated with mechanosensory sensilla. The function of gustatory cells in the wing of Drosophila remains enigmatic and actually quite unknown (Stocker, 1994). Our work consisted in exploring the signaling and the transduction mechanisms of these receptors and in questioning their importance in the adaptation of insects to their ecosystem. Our results are based on three components. We have verified that the expression of gustatory receptors occurs in the wings of three different insects (Drosophila, aphid and honey bee) by RT-PCR. We have studied the function of these receptors vis-à-vis of sweet and bitter molecules using a transgenic line (G-CaMP) that exhibits a strong fluorescence provoked by cytosolic calcium picks. Finally, behavioral assays have been realized with a transgenic line (Poxn*) in which the chemosensory sensilla have been invalidated without altering the other olfactory and gustatory structures. Our results show a significant effect of wing chemosensory cells as far as orientation is space and Bayesian learning and have permitted us to elaborate hypothesis regarding the neuroanatomical evolution of the wing of insects since ancestral organisms of marine origin from which they derive. Experts in aerodynamics propose the creation of a vortex during flight that forms a spiral of air along the anterior border of the wing. The perfect superposition between this vortex and the costal nerve of the wing allows us to deduce that the vibrations of the insect wing between 50 and 1.000 Hertz are able to nebulize materials (microdust, microdrops, weakly volatile molecules), which are captured/trapped in the vortex and addressed to the gustatory sensilla. Our hypothesis is that this mechanism would let pollinator insects taste flowers without landing and without involving the proboscis. In this scenario insects would dissociate taste from ingestion, avoiding poisoning by toxic molecules emitted by plants and rending exploration more efficient by minimizing searching time.
|
14 |
L’alimentation des personnes âgées : étude sensorielle des fruits et légumes enrichis / Elderly people’s diet : sensory study of enriched fruit and vegetablesMingioni, Mathieu 24 November 2016 (has links)
Face à une population vieillissante et à la prévalence du risque de dénutrition, cette thèse s’est intéressée à comprendre comment développer des produits nutritionnellement et sensoriellement adaptés à l’alimentation des personnes âgées en s’appuyant sur les outils sensoriels.Grâce à une enquête comparative multidisciplinaire réalisée dans 5 pays européens, nous avons mis en évidence trois grands profils d’habitudes et de préférences alimentaires chez des personnes âgées dépendantes pour leur alimentation (n=405). Malgré ces différences, nous fournissons une liste de fruits et légumes consensuels dans les pays étudiés.Chez 130 personnes âgées de plus de 65 ans, nous confirmons la variabilité des performances sensorielles.Nous apportons des résultats originaux quant à la discrimination gustative encore très peu étudiée. Elle resterait stable avant 80 ans mais semblerait diminuer ensuite. Enfin, aucun lien n’a été trouvé entre perceptions sensorielles et appréciation de différentes purées de pommes. Dans un contexte d’innovation, nos résultats précisent un cahier des charges en recommandant des plages de variations possibles pour les concentrations de sucre et d’acide utilisées en purées de pommes.Enfin, avec un panel expert et 344 personnes âgées,nous montrons qu’un enrichissement vitaminique ne modifie pas la perception de smoothies ; alors qu’une supplémentation en protéines (pois et blé) dégrade des purées de carottes sur le plan sensoriel et hédonique.Nos résultats illustrent l’importance des outils sensoriels dans un processus de développement produit ainsi que leur intégration dans une démarche d’innovation / In a context of aging population and rising prevalence of malnutrition, the aim of this PhD thesis was to understand how to develop innovative food products that are nutritionally and sensorially adapted to elderly people’s diet using sensory tools. A comparative multidisciplinary survey was performed in 5 European countries. We highlighted three main patterns of food habits and preferences in elderly people with culinary dependency (n=405). Despite those differences, we deliver a list of consensual fruit and vegetables (in the studied countries). With 130 elderly people aged over 65 years old, we confirm the variability of sensory performances. We report original findings about gustatory discrimination abilities in which very few is known. Gustatory discrimination ability seems to remain stable before 80 years old but may decrease after. No link was found between sensory perceptions and appreciation for different apple purees. In a context of innovation, our results precise specifications by providing recommendations about possible ranges for sugar and acid concentrations to be used in apple purées. Finally, using a sensory expert panel and 344 elderly people, we show that smoothies were not affected by the addition of vitamins. However, a protein supplementation (pea and wheat) significantly decreases sensory characteristics and hedonic evaluation of carrot purées. Our results highlight the importance of sensory tools in a product development approach. It is important to include them all along the process of innovation.
|
15 |
L’impact de l’activité physique aiguë et chronique sur les perceptions gustativesGauthier, Alexandre-Charles 03 1900 (has links)
Le goût et ses différentes caractéristiques sont des parties fondamentales de notre alimentation et sont des agents régulateurs qui permettent d’identifier les nutriments et d’évaluer le contenu alimentaire. Par cette capacité, l’humain est capable d’orienter ses comportements alimentaires en fonction de ses perceptions gustatives. L’âge, le sexe ainsi que la présence de différentes carences, de différents traitements pharmacologiques, de différents virus ou de maladies neurodégénératives font tous partie des paramètres qui peuvent influencer nos perceptions gustatives. De récentes évidences suggèrent que l'obésité pourrait aussi être liée à des altérations gustatives, avec une sensibilité réduite et une perception accrue du goût sucré chez les personnes avec un indice de masse corporelle plus élevée. Les personnes qui vivent avec des altérations gustatives sont exposées à plus de risques d’avoir un apport énergétique inadéquat en plus de favoriser à la fois une possible suralimentation ou même sous-alimentation en fonction de leur profil. L’activité physique semblerait être une possible piste de prévention et de traitements pour différents problèmes liés au goût. Mon projet de thèse vise donc à : 1) Faire une recension des écrits sur le lien entre l'activité physique pratiquée de façon aiguë et chronique et son impact sur le goût, 2) Étudier les changements aigus du goût lors d’une condition d’activité physique dans une population sous-étudiée, soit les jeunes, et 3) Identifier quel est l'impact de l'intensité de l'activité physique, mais aussi du statut pondéral et du sexe, sur le goût lorsque pratiqué sur une base régulière. Les études réalisées ont permis de mettre en lumière que l’activité physique peut influencer le goût, favorisant les goûts sucré et umami, réduisant le salé et l'acide. Des différences entre l'activité physique aiguë et chronique, des variations entre hommes et femmes et pour différents statuts pondéraux ont également été notées. Ces résultats pourraient permettre d'adopter des changements au mode de vie pour potentiellement améliorer le goût, et ainsi améliorer l’impact de l’activité physique sur le profil alimentaire. Dans l'ensemble, ces données ouvrent la voie vers des études qui auront pour but d’optimiser et de promouvoir un mode de vie actif comme un élément clé dans la prévention et le traitement des troubles liés au goût. / Taste and its different characteristics are fundamental parts of our diet and are regulatory agents that allow the identification of nutrients and the assessment of food content. Through this ability, humans can direct their eating behaviours based on their taste perceptions. Age, sex, as well as the presence of various deficiencies, pharmacological treatments, viruses, or neurodegenerative diseases are all parameters that can influence our taste perceptions. Recent evidence suggests that obesity might also be related to taste alterations, with a reduced sensitivity and an increased perception of sweet taste in people with a higher body mass index. Individuals living with taste alterations are exposed to a higher risk of having inadequate energy intake, in addition to promoting both possible overeating or undernutrition depending on their profile. Physical activity seems to be a possible prevention and treatment approach for various taste-related issues. Therefore, my thesis project aims to: 1) Review the literature on the link between physical activity performed acutely and chronically and its impact on taste, 2) Study the acute changes in taste during a condition of physical activity in an understudied population, namely the youth, and 3) Identify the impact of the intensity of physical activity, but also of the weight status and sex, on taste when practised on a regular basis. The conducted studies have highlighted that physical activity can influence taste, favouring sweet and umami tastes, reducing salty and sour ones. Differences between acute and chronic physical activity, variations between men and women, and for different weight statuses have also been reported. These results could allow the adoption of lifestyle changes to potentially improve taste function, and thus improve the impact of physical activity on the dietary profile. Overall, these data could pave the way for studies that aim to optimize and promote an active lifestyle as a key element in the prevention and treatment of taste-related disorders.
|
16 |
Etude de la signalisation calcique dans les cellules gustatives lipidiques chez la souris / The study of calcium signaling in lipid gustatory cells in miceDramane, Gado 08 October 2012 (has links)
Les personnes en surcharge pondérale semblent préférer une alimentation riche en graisse. Face à l'épidémie d'obésité qui touche nos Sociétés tant urbaines que rurales, élucider les mécanismes de la détection des lipides alimentaires devient un enjeu majeur. Il avait précédemment été admis que la glycoprotéine CD36 exprimée dans les papilles caliciformes de souris, est impliquée dans la perception oro-gustative des lipides alimentaires. Dans ce travail, nous avons montré que l'acide linoléique (LA), en activant les phospholipases A2, sPLA2, cPLA2 et iPLA2 via CD36, produit de l'acide arachidonique (AA) et la lyso-phosphatidylcholine (lyso-PC). LA déclenche un influx calcique dans les cellules CD36-positives et induit la production du facteur CIF (Calcium Influx Factor). CIF, AA et lyso-PC exercent différentes actions sur l'ouverture des canaux SOC (Stored Operated Calcium Channel) constitués de protéines Orai et contrôlés par STIM1. Stim1 est un senseur calcique situé sur la membrane du réticulum endoplasmique activé par la déplétion du calcium intracellulaire. Nous avons utilisé la technologie siRNA et des modèles de souris transgéniques pour montrer que CIF et lyso-PC activent des canaux calciques homodimériques composés de protéines Orai1 tandis qu’AA active des canaux hétéro-pentamériques composés d’Orai1 et Orai3. Nous avons également montré que STIM1 régule la production de CIF dans les cellules stimulées par la thapsigargine et l’acide linoléique ainsi que l'ouverture de deux types de canaux calciques. Par ailleurs les souris au phénotype Stim1-/- perdent la préférence spontanée pour les lipides observé chez les animaux de type sauvage. D’un autre côté les cellules CD36-positive de souris Stim1-/- sont incapables de libérer la sérotonine dans l'environnement extracellulaire. Nos résultats suggèrent que des acides gras à longue chaine (AGLC) induisent la signalisation calcique régie par STIM1 via CD36. La perception oro-gustative des lipides alimentaires détermine la préférence spontanée pour les lipides observée chez les mammifères / The lipid-binding glycoprotein CD36, expressed by circumvallate papillae (CVP) of the mouse tongue, has been shown to be implicated in oro-gustatory perception of dietary lipids. We demonstrate that linoleic acid (LA) by activating sPLA2, cPLA2 and iPLA2 via CD36, produced arachidonic acid (AA) and lyso-phosphatidylcholine (Lyso-PC) which triggered Ca2+ influx in CD36-positive taste bud cells (TBC), purified from mouse CVP. LA induced the production of Ca2+ influx factor (CIF). CIF, AA and Lyso-PC exerted different actions on the opening of store-operated Ca2+ (SOC) channels, constituted of Orai proteins and regulated by STIM1, a sensor of Ca2+ depletion in the endoplasmic reticulum. We used siRNA technology and transgenic mice models and observed that CIF and Lyso-PC opened Orai1 channels whereas AA-opened Ca2+ channels were composed of Orai1/Orai3. STIM1 was found to regulate LA-induced CIF production and opening of both kinds of Ca2+ channels. Furthermore, Stim1–/– mice lost the spontaneous preference for fat, observed in wild-type animals. The CD36-positive TBC from Stim1–/– mice also failed to release serotonin into extracellular environment. Our results suggest that fatty acid-induced Ca2+ signaling, regulated by STIM1 via CD36, might be implicated in oro-gustatory perception of dietary lipids and the spontaneous preference for fat
|
17 |
Development of Novel Tasks to Assess Outcome-Specific and General Pavlovian-to-Instrumental Transfer in HumansBelanger, Matthew J., Chen, Hao Chen, Hentschel, Angela, Garbusow, Maria, Ebrahimi, Claudia, Knorr, Felix G., Zech, Hilmar G., Pilhatsch, Maximilian, Heinz, Andreas, Smolka, Michael N. 22 February 2024 (has links)
Introduction: The emergence of Pavlovian-to-instrumental transfer (PIT) research in the human neurobehavioral domain has been met with increased interest over the past two decades. A variety of PIT tasks were developed during this time; while successful in demonstrating transfer phenomena, existing tasks have limitations that should be addressed. Herein, we introduce two PIT paradigms designed to assess outcome-specific and general PIT within the context of addiction. - Materials and Methods: The single-lever PIT task, based on an established paradigm, replaced button presses with joystick motion to better assess avoidance behavior. The full transfer task uses alcohol and nonalcohol rewards associated with Pavlovian cues and instrumental responses, along with other gustatory and monetary rewards. We constructed mixed-effects models with the addition of other statistical analyses as needed to interpret various behavioral measures.- Results: Single-lever PIT: both versions were successful in eliciting a PIT effect (joystick: p < 0.001, ηp² = 0.36, button-box: p < 0.001, ηp ² = 0.30). Full transfer task: it was determined that the alcohol and nonalcoholic reward cues selectively primed their respective reward-associated responses (gustatory version: p < 0.001, r = 0.59, and monetary version: p < 0.001, r = 0.84). The appetitive/aversive cues resulted in a general transfer effect (gustatory: p < 0.001, ηp² = 0.09, and monetary: p < 0.001, ηp ² = 0.17). - Discussion/Conclusion: Single-lever PIT: PIT was observed in both task versions. We posit that the use of a joystick is more advantageous for the analysis of avoidance behavior. It evenly distributes movement between approach and avoid trials, which is relevant to analyzing fMRI data. Full transfer task: While gustatory conditioning has been used in the past to elicit transfer effects, we present the first paradigm that successfully elicits both specific and general transfers in humans with gustatory alcohol rewards.
|
18 |
Etude du contrôle hédonique de la prise alimentaire par l'analyse des potentiels évoqués gustatifs / Study of hedonic control of food intake using gustatory evoked potentialsJacquin-Piques, Agnès 13 October 2016 (has links)
Les techniques d’électrophysiologie chez les animaux et d’imagerie fonctionnelle chez l’Homme ont permis d’étudier le contrôle hédonique de la prise alimentaire. Ce contrôle hédonique n’a cependant jamais été exploré chez l’Homme par l’étude des potentiels évoqués gustatifs (PEG), de meilleure résolution temporelle que l’imagerie fonctionnelle. Le premier objectif de la thèse a été de mettre au point une technique fiable et reproductible de recueil des PEG, en regard des aires cérébrales gustatives, en réponse à une stimulation sapide. Le deuxième objectif a été d’étudier les variations des PEG en fonction de la valeur hédonique de la prise alimentaire. Le travail de thèse a permis de mettre au point l’enregistrement des PEG, réalisés chez plus de 100 jeunes sujets sains. Les comparaisons effectuées entre les enregistrements cérébraux obtenus en réponse à l’eau seule ou à l’huile de paraffine, solutions non palatables, et après stimulation par une solution sapide ont permis d’apporter des arguments forts en faveur de l’origine gustative des potentiels évoqués enregistrés. L’analyse des PEG a permis de mettre en évidence des modifications de l’activation cérébrale en fonction du plaisir alimentaire, traduites par des changements de latence ou d’amplitude des PEG. Plusieurs situations connues pour faire varier le plaisir alimentaire ont été étudiées : avant/après repas ; stimulation par des solutions sucrées d’intensités différentes ou de valeurs énergétiques différentes ; stimulation par des acides gras. Des PEG en réponse aux acides gras à longue chaine (acides linoléiques) ont été enregistrés par ce biais, renforçant l’hypothèse du «gras» en tant que sixième saveur primaire. / Hedonic control of food intake has been studied using neurophysiological investigations in animals and functional imaging in humans. Gustatory evoked potentials (GEPs), a higher time resolution technique than functional imaging, have never been used for this purpose. The first aim of this thesis was to establish a reliable recording of GEPs in humans, in response to a sapid stimulus. The second aim was to determine the GEPs modifications according to the hedonic value of food intake. GEPs recording was performed in response to an intermittent stimulation of a sapid solution in more than 100 young healthy subjects. The comparisons between cerebral recordings in response to water or paraffin oil, non palatable solutions, and in response to sapid solutions (sucrose, sodium chlorure and fatty acids) allow us to advance strong arguments for the gustative nature of the recorded evoked potentials. GEPs analysis underlined changes in cerebral activation according to the hedonic value of the stimulus. These changes in cerebral activation were highlighted by modifications of GEPs latency or amplitude. Several physiological situations, marked by different pleasantness of food stimulation, were studied: before/after food intake, stimulation by sweet solutions with different concentrations or different caloric contents, stimulation by fatty acids. Moreover, GEPs in response to long chain fatty acids (linoleic acids) were recorded, reinforcing the hypothesis that fatty acids could be the sixth primary flavor.
|
19 |
<b>Investigation of odorant receptors associated with nestmate recognition in the Argentine ant, </b><b><i>L</i></b><b><i>inepithema humile</i></b>Mathew A. Dittmann (5930612) 18 April 2024 (has links)
<p dir="ltr">Given the relatively poor visual acuity of compound eyes, many insects have developed alternative means for navigating their environment. For example, insects often rely on chemosensation to find food, mates, and inter- and intraspecific communication. Eusocial insects in particular have developed complex systems of pheromone communication to organize their colonies, enabling them to partition labor for foraging, brood care, and colony defense tasks to different portions of the colony. A variety of genes coding for proteins are involved in detecting these chemicals, including gustatory receptors, ionotropic receptors, and odorant receptors (ORs). Eusocial insects, and especially ants, have evolved an expanded clade of ORs in their genome, likely due to an increased reliance on pheromones compared to other insects. The ability to recognize nestmates from non-nestmates is one of the vital functions performed by these ORs, which detect hydrocarbons present on the cuticle to distinguish friend from foe. However, research into the details of nestmate recognition has been stymied due to difficulties in manipulating OR genes. Despite advances in genetic sequencing and manipulation technologies, strict reproductive divisions within most ant lineages make generating transgenic ants nearly impossible, and so we have been left with limited options to further investigate these receptors. To narrow down the ORs that could be involved in nestmate recognition in the Argentine ant (Mayr, 1868), I took a multi-pronged approach of generating tissue transcriptomes to identify ORs that are selectively upregulated in the antennae, as well as conducting a phylostratigraphic analysis to identify which OR genes arose more recently in the Argentine ant genome. While conducting these analyses, it became necessary to reannotate the set of Argentine ant OR genes, due to current published annotations not containing the full breadth of <i>L. humile</i> ORs. Finally, I orally administered fluorescently-labelled dsRNA to workers, and tracked the extent to which ingested dsRNA is capable of traversing the tissues of ant workers, to investigate whether RNAi is a viable method for investigating gene function for genes showing tissue-selective expression. I discovered a subset of OR genes that are highly expressed in the antennae and confirmed that dsRNA is able to reach the antennae and knock down OR gene expression through ingestion, meaning that RNA interference is a viable method for the practical study of ant OR genes and can be used to further explore how individual ORs regulate nestmate recognition.</p>
|
20 |
Предикати перцепције у руском и српском језику / Predikati percepcije u ruskom i srpskom jeziku / Predicates of Perception in Russian and SerbianPopović Dragana 23 June 2016 (has links)
<p>Ovim se istraživanjem na primeru osnovnih predikata (glagola) percepcije ruskog i srpskog jezika odgovara na pitanja vezana za sistemske odnose u oblasti leksike, klasifikaciju jezičkih jedinica, definisanje leksema, međusobnu zavisnost značenja leksema i njihovih morfoloških i sintaksičkih obeležja. Osnovni predikati (glagoli) percepcije ruskog i srpskog jezika pozicioniraju se unutar semantičkih paradigmi, zasnovanih na interakciji diferencijalnih i zajedničkih komponenata značenja svojih članova. Članovi paradigmi izdvajaju se na osnovu kriterijuma određenih u skladu s principima organizacije centra i periferije leksičkog sistema. Pozicioniranje izdvojenih predstavnika vizuelne, auditivne, olfaktorne, gustativne i taktilne percepcije, kao i njihovih vidskih korelata, rezultira utvrđivanjem strukture paradigmi i smerova semantičke derivacije u njima.</p> / <p>This dissertation focuses on systemic relationships among the basic predicates (verbs) of perception in Russian and Serbian. It investigates issues related to the lexicon, the classification of linguistic units, the relationships between the meanings of lexemes and their morphological and syntactic features, as well as the definition of the main members of the analysed lexico-semantic group. The basic predicates of perception in Russian and Serbian are positioned within the semantic paradigms, based on the interaction of differential and general components of meaning of their members. The members of the paradigms are selected based on criteria established in accordance with the principle of the organization of lexical systems into core and periphery. The positioning of the selected representatives of visual, auditory, olfactory, gustative and tactile perception, as well as their aspectual correlates, results in determining the structure of the paradigms and the directions of semantic derivation in them.</p>
|
Page generated in 0.0545 seconds