Dissertations / Theses on the topic 'Taste gene'

Fertility is decreasing worldwide and male infertility factors contribute to approximately 30% of all infertility cases. The causes of this condition are often unknown, and about 40% of infertile men are oligozoospermic or azoospermic despite normal reproductive hormonal profile, presenting a condition of idiopathic infertility. Several studies have demonstrated the expression of taste receptors and their signaling transduction cascade in the male reproductive system, highlighting the potential role of response to chemical stimuli of taste receptors and their possible involvement in sperm maturation as well as in sperm behavior and fertilization. Considering the strong genetic component in male infertility, and the evidence that polymorphic variant in the gene are often functional, this thesis investigates the possible role of taste receptors in spermatogenesis, as well as the functional effect of selected taste receptor polymorphisms in male fertility. We hypothesized that polymorphisms in taste receptors genes might influence sperm functionality, in term of sperm parameters, as well as sperm behavior and fertilization. To this end we conducted a study to identify possible novel markers of susceptibility in human infertility within the taste receptor clusters. We selected 19 SNPs in 12 taste related genes that have been reported to be expressed in human and or mice testis or sperm and analyzed a possible correlation with different types and degrees of male infertility. For this purpose we enrolled 494 male patients, undergoing spermiogram at the Centre of Couple Sterility, Siena University Hospital. All patients were characterized for main sperm parameters, according to WHO (2010) guidelines, and were genotyped for 19 SNPs in taste receptors genes, using the KASPar SNP genotyping system. To assess the possible functional associations between SNPs and sperm parameters, different bioinformatic tools were used. Among the 19 SNPs investigated in this study for their potential association with male infertility, we found that TAS2R14-rs3741843, TAS1R2-rs4920566 and TAS2R3-rs11763979 showed the strongest significant association with specific sperm parameters. In particular, the homozygous carriers of the minor (G) allele of the TAS2R14-rs3741843 SNP showed a decreased sperm progressive motility compared to common (A) homozygous (coefficient= -0.46; P=0.003). Moreover, GTEx we showed that TAS2R14-rs3741843 has a plethora of expression quantitative trait loci (eQTL) in various tissues, and in the testicular tissue the SNP has one of the biggest effect size, suggesting its importance in this tissue. In addition, we analyzed, in human ejaculated sperm, the gene expression profile of the selected taste receptors, as well as of several genes involved in the signal transduction cascade elicited by these receptors. We partially confirmed the obtained data from the gene expression analysis at the protein level both in human sperm as well as in mouse sperm and testis (this study has been carried out during my training period at the Walther Straub Institute, Ludwig-Maximilians-University Munich). In particular, by using the Western blot and immunohistochemical techniques, we focused on the bitter receptor TAS2R4, TAS2R14, and the umami receptor TAS1R1 and the G proteins α-gustducin and α-transducin. Since we observed the expression of the detected proteins in the male reproductive system, we carried out the same analysis in the female somatic follicular cells, namely cumulus and granulosa cells, that play an important role in the oocyte competence acquiring and fertilization process . Immunofluorescence assay revealed a cytoplasmic localization in cumulus cells and granulose cells, in particular around the nucleus, probably in the transition region between rough endoplasmic reticulum and Golgi apparatus, where the protein concentration inside vesicles prelude to an active transport/release from these cells. In conclusion, our results suggest a role of genetic variability of taste receptors in human male infertility, as indicated by the significant correlation with the main sperm, and the expression of several components of taste receptor transduction cascade in male and female gametes

Thesis (Ph. D.)--University of California, San Diego, 2007.
Title from first page of PDF file (viewed January 10, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 130-140).

Intensive Forschung hat in den vergangenen Jahrzehnten zu einer sehr detaillierten Charakterisierung des Geschmackssystems der Säugetiere geführt. Dennoch sind mit den bislang eingesetzten Methoden wichtige Fragestellungen unbeantwortet geblieben. Eine dieser Fragen gilt der Unterscheidung von Bitterstoffen. Die Zahl der Substanzen, die für den Menschen bitter schmecken und in Tieren angeborenes Aversionsverhalten auslösen, geht in die Tausende. Diese Substanzen sind sowohl von der chemischen Struktur als auch von ihrer Wirkung auf den Organismus sehr verschieden. Während viele Bitterstoffe potente Gifte darstellen, sind andere in den Mengen, die mit der Nahrung aufgenommen werden, harmlos oder haben sogar positive Effekte auf den Körper. Zwischen diesen Gruppen unterscheiden zu können, wäre für ein Tier von Vorteil. Ein solcher Mechanismus ist jedoch bei Säugetieren nicht bekannt. Das Ziel dieser Arbeit war die Untersuchung der Verarbeitung von Geschmacksinformation in der ersten Station der Geschmacksbahn im Mausgehirn, dem Nucleus tractus solitarii (NTS), mit besonderem Augenmerk auf der Frage nach der Diskriminierung verschiedener Bitterstoffe. Zu diesem Zweck wurde eine neue Untersuchungsmethode für das Geschmackssystem etabliert, die die Nachteile bereits verfügbarer Methoden umgeht und ihre Vorteile kombiniert. Die Arc-catFISH-Methode (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), die die Charakterisierung der Antwort großer Neuronengruppen auf zwei Stimuli erlaubt, wurde zur Untersuchung geschmacksverarbeitender Zellen im NTS angewandt. Im Zuge dieses Projekts wurde erstmals eine stimulusinduzierte Arc-Expression im NTS gezeigt. Die ersten Ergebnisse offenbarten, dass die Arc-Expression im NTS spezifisch nach Stimulation mit Bitterstoffen auftritt und sich die Arc exprimierenden Neurone vornehmlich im gustatorischen Teil des NTS befinden. Dies weist darauf hin, dass Arc-Expression ein Marker für bitterverarbeitende gustatorische Neurone im NTS ist. Nach zweimaliger Stimulation mit Bittersubstanzen konnten überlappende, aber verschiedene Populationen von Neuronen beobachtet werden, die unterschiedlich auf die drei verwendeten Bittersubstanzen Cycloheximid, Chininhydrochlorid und Cucurbitacin I reagierten. Diese Neurone sind vermutlich an der Steuerung von Abwehrreflexen beteiligt und könnten so die Grundlage für divergentes Verhalten gegenüber verschiedenen Bitterstoffen bilden.
Intense research in the past decades has led to a detailed understanding of the mammalian taste system. Some important issues, however, have remained unanswered with the established methods that have been applied so far. One of these questions is whether different bitter substances can be distinguished. There are thousands of compounds which taste bitter to humans and elicit innate aversive behavior in animals. Moreover, these bitter substances are very heterogeneous regarding their structure as well as their effect on the organism. While many bitter tastants are potent poisons, others are harmless or even have beneficial effects in the amounts that are typically ingested. The ability to discriminate between those groups of bitter tastants could be an evolutionary advantage. Such a mechanism, however, is not known for mammals. The aim of this thesis was to study the processing of taste information in the first station of gustatory processing in the mouse brain, the nucleus of the solitary tract (NTS). Of particular interest was the question concerning discrimination of bitter tastants. To this end a new method was established for the taste system combining the advantages of methods used before while circumventing their disadvantages. The Arc catFISH method (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), which allows the characterization of responses of large neuron populations to two stimuli, was used to analyze taste-processing cells in the NTS. In the course of this project a stimulus-induced Arc expression in the NTS was shown for the first time. The results demonstrated that Arc expression in the NTS appears specifically after stimulation with bitter tastants and that the Arc expressing neurons are located primarily in the gustatory part of the NTS. This indicates that Arc expression is a marker for bitter-processing gustatory neurons in the NTS. Upon stimulating twice with bitter compounds, distinct, yet overlapping neuron populations were identified, that reacted differently to the three bitter substances cycloheximide, quinine hydrochloride, and cucurbitacin I. Presumably these neurons are involved in the regulation of aversive reflexes and could form a basis for divergent behavior towards different bitter substances.

The evolutionary history of H. neanderthalensis, interwoven with that of H. sapiens, has always fascinated the scientific world. Recent adavncess in paleogenetics shedds new light on the phylogenetic relationship between Neandertals and modern humans. The studies developed in this thesis intend principally to control the contaminants through the development of an anti-contamination protocol for decreasing the human contamination in pre-laboratory phases. We designed a PCR-based method specific for reducing human contamination during the laboratory analysis, and we analyzed the fragmentation pattern of the ancient sequences by massively parallel sequencing technologies. Furthermore, we studied two nuclear genes, TAS2R38 -associated to bitter taste perception- and ABO blood group system –involved in natural immunity- that provide specific information on aspects of the Neanderthal phenotype and adaptation.
La historia evolutiva d’H. neanderthalensis, imbricada amb la d’H. sapiens, ha fascinat sempre el món científic. Avenços recents en paleogenètica aporten una nova llum sobre la rel•lació filogenètica entre els neandertals i els humans moderns. Els treballs d’aquesta tesi intenten principalment controlar els contaminants mitjançant el desenvolupament d’un protocol d’anti-contaminació que disminueixi la contaminació humana de les mostres en la fase de pre-laboratori. Hem desenvolupat un mètode basat en la PCR específic per a reduïr els contaminants humans durant l’anàlisi en el laboratori, i hem analitzat el patró de fragmentació de les seqüències antigues amb tècniques de seqüenciació massiva en paral•lel. A més a més, hem estudiat dos gens nuclears, el TAS2R38 –associat a la percepció del gust amarg- i el grup sanguini ABO –implicat en la immunitat natural- que proporcionen informació específca sobre aspectes del fenotip i de les adaptacions dels neandertals.

The taste of foods is perceived as one or a combination of five sensations which are sweet, sour, bitter, salty and umami. The umami taste is best described as a savoury sensation (Ikeda, 2002) and it is of central importance in food flavour. The mammalian taste receptors TIRs form two heteromeric G-protein-coupled receptor complexes and taste receptors T 1 R 1 and T 1 R3 function together as an umami taste detector on the tongue (Nelson et al., 2002; Li et al., 2002; Zhao et al., 2003). It is already well established that monosodium glutamate and L-aspartate evoke the umami sensation and are highly detected by these taste receptors (Li et aI., 2002). Yamaguchi (1991) and Ninomiya (1998) reported that umami flavour is enhanced in the presence of inosine monophosphate (IMP). This project aims to develop an in vitro assay that could mimic human perception of umami so that it will be possible to screen extracts of the tomato introgression lines (ILs) for novelumami compounds. A functional umami calcium assay based on G-protein coupled receptor signaling was used to test pure compounds of monosodium glutamate (MSG), inosine-5'monophosphate (IMP) and the ctude tomato IL extracts. The calcium assay was not suitable for use on ctude tomato extracts because the crude samples elicited non specific responses. This led to the development of another high-throughput assay based on a different principle known as the bioluminescence resonance energy transfer (BRET2). This assay was designed to study interactions between proteins through resonance energy transfer between the donor molecule (Rluc) and the acceptor molecule (GFp2). Umami receptors were cloned into an expression vector with the reporter constmcts and then transfected into Flp-In T -Rex cells. Stably transformed cells were challenged with MSG, IMP and crude tomato IL extracts. Additionally transgenic plants were generated with altered expression of GAD and AMP deaminase to modulate the levels of umami compounds in tomato. The BRET2 assay demonstrated the ability of this system to respond to different levels of MSG and IMP through reproducible dose response curves and also established a good correlation with the in vivo sensory panel results. Tests on the ctude tomato IL lines generated umami responses. Lines with low levels of glutamic acid showed high BRET2 response values which suggest the presence of enhancers in the tomato extracts that contributed to the umami taste intensity. The knockout of the GAD gene to increase glutamate levels in plants was unsuccessful. However, overexpression of AMP deaminase produced plants at To generation, which will be the subject of future analysis. Future work will involve the optimization of the newly developed umami BRET2 assay to improve robustness and reproducibility. This assay then can be utilized as a universal umami screen for complex samples, including those from the AMP deaminase plants.

In this thesis, we studied two examples of the sensitivity to chemical stimuli and its role in the food preferences in two models of the evolutionary scale. The red swamp crayfish Procambarus clarkii (Girard, 1852) (Crustacea: Decapoda) is an invasive species of freshwater habitats that has spread worldwide. In crayfish, like in other decapod crustaceans, reception of chemical cues occurs by way of peripheral chemoreceptors grouped within sensory hairs and typically located on the cuticle of cephalothoracic appendages. Antennules and pereopods (walking legs), in particular, have been reported to be olfactory organs involved in a number of behavioral responses, such as, sex recognition and localization of food sources in the environment. By way of extracellular nerve recordings coupled with behavioral bioassays, we investigated the sensitivity spectra of the walking leg chemoreceptors in the crayfish P. clarkii in response to different compounds of feeding significance and related to its omnivorous habits. Our results confirmed a marked sensitivity of the legs to trehalose, cellobiose, sucrose, maltose, glycine and leucine. Some sensitivity to glucose, fructose, asparagine (all food indicators) and taurocholic acid was also found, the sugar-sensitive chemoreceptor units resulting as broadly tuned to the carbohydrates. Responses were highly phasic to trehalose (hemolymph sugar in the body fluid of many invertebrates), phasic to glycine and leucine and phasic-tonic to the other compounds. This suggests that chemoreceptor phasicity is an additional property for better discrimination of the protein components in the diet from other stimuli. The behavioral bioassays excluded, at least under confined experimental conditions, any involvement of antennules in the detection of food-related compounds, thus emphasizing the role of the crayfish legs as the main short-distance, broad-spectrum sensors for feeding. Such information may be valuable for the identification of key chemicals aimed at the future development of strategies for crayfish population control programs. Taste sensitivity varies greatly in humans, influencing eating behavior and therefore may play a role in body composition. PROP bitter taste sensitivity is the most studied example of the individual variability of taste sensitivity. Some studies show that PROP bitter taste sensitivity may be correlated with sensitivity to other oral stimuli, food preferences and BMI, while other studies did not confirm this association. It is known that PROP phenotype is associated with variant in bitter taste receptors TAS2R38 and with density of fungiform papillae on tongue surface. Although most of PROP phenotypic variations are explained by the allelic diversity of the bitter receptor TAS2R38, they cannot explain the PROP taster status-related differences above all that in the perception to different oral stimuli. The aim of this study was identify and characterize other factors that may contribute to differences in the genetic predisposition to taste PROP and identify confounding variables which may explain the controversial data in the literature about the relationship between PROP taste sensitivity and BMI. 1) We investigated the possible relationship between PROP bitter taste responsiveness and salivary proteins by using HPLC-ESI-MS on saliva sample before and after PROP taste stimulation. 2) We evaluated the role of proteins and free amino acids in modulating bitter taste responsiveness. Subjects rated PROP bitterness after supplementation of two salivary proteins (Ps-1 and II-2), and the free form of constituent amino acids of the two proteins sequences (L-Arg and L-Lys) whose interaction with PROP was demonstrated by 1H-NMR spectroscopy. 3) We investigate the role of polymorphism rs2274333 (A/G) in the gene that codify for the salivary trofic factor gustin protein, in PROP sensitivity and fungiform papilla density and morphology and in vitro we investigate the effect of this gustin gene polymorphism on cell proliferation and metabolic activity, following treatment with saliva of individuals with and without the gustin gene mutation, and with isolated protein, in the two iso-forms. 4) We investigated whether the endocannabinoid system, which modulates hunger/satiety and energy balance, plays a role in modulating eating behaviour influenced by a sensitivity to PROP which could explain the controversial data in literature. In particular we determined the plasma profile of the endocannabinoids 2-arachidonoylglycerol (2-AG), anandamide (AEA) and congeners in normal-weight PROP super-tasters and non-tasters, also we assessed the cognitive eating behavior disorder by the Three-Factor Eating Questionnaire. The results showed that: 1) Basal levels of II-2 and Ps-1 proteins, belonging to the basic proline-rich protein (bPRPs) family, were significantly higher in PROP super-taster than in non-taster unstimulated saliva, and PROP stimulation elicited a rapid increase in the levels of these same proteins only in PROP super-taster saliva. 2) Supplementation of Ps-1 protein in individuals lacking it in saliva enhanced their PROP bitter responsiveness. 1H-NMR results showed that the interaction between PROP and L-Arg is stonger than that involving L-Lys, and taste experiments confirmed that oral supplementation with L-Arg increase more PROP bitterness intensity than L-Lys. 3) Gustin and TAS2R38 genotypes were associated with PROP threshold, while bitterness intensity was mostly determined by TAS2R38 genotypes. Fungiform papillae densities were associated with both genotypes (with a stronger effect for gustin), but papilla morphology was a function of gustin alone. In vitro experiment, the treatment of isolated cells with saliva from individuals with AA form, and direct application of the active iso-form of gustin protein, increased cell proliferation and metabolic activity. 4) The disinhibition score of non-taster was higher than those of super-tasters. In addition, we found that the concentration of endocannabinoid AEA (anandamide) and 2-AG (2-arachidonoylglycerol) was lower in the plasma of non taster compared with super-tasters subjects. In conclusion, among the factors contributing to individual differences of PROP sensitivity, in addition to the TAS2R38 variants with its different affinity for the stimulus, we found: 1-2) the specific salivary proteins of bPRP family (Ps-1) and L-Arg that could be involved in twist and turn of the PROP molecule, thus facilitating its binding with the receptor. 3) A gustin gene polymorphism that, by modulating the protein activity, controls the growth and maintenance of taste buds and 4) the higher disinhibition behaviour in non-tasters may be compensated in part, in normal-weight subjects, by the decrease of peripheral endocannabinoids to downregulate the hunger-energy intake circuitry.

This thesis examines the rise to prominence of a new form of “quality television” that has appeared in the U.S. since the 1990s. There are competing and sometimes conflicting ways to define “quality television”, depending on different histories and prioritising different characteristics - sometimes production methods, sometimes viewing and distribution practices, and sometimes genre hybridity and transformation. For each, however, the 1990s is a watershed decade. The mainstreaming of cable television, the new dominance of video and then DVD collections of series, a decline in broadcast television’s audience share and the rapid expansion of the internet as an entertainment media option together created new opportunities for a more ‘cinematic’ television that hailed an active audience interested in formally and narratively challenging television. Every account of quality television turns on claims to exceed and subvert the expectations of existing television formats and genres while also using those to attract an audience. This is famously exemplified by the 90s HBO slogan “It’s not TV. It’s HBO” (since 2011 just “it’s HBO”). This apparent difference is only partly about heightened production values. Quality television tends to foreground genre hybridity, genre self-reflexivity, and intertextuality, and its viewers have become associated with dedicated fandom and new viewing practices such as “binge viewing”, the increasing frequency of watching “off-air”, and torrent culture. The quality television viewer is appealed to by, and not in spite of, their status as a niche audience, and the cultural value accruing to their niche status has transformed investment in casting, scripting, acting directing, producing and critically evaluating television. Quality television has not only become a dominant television format but the benchmark against which “mainstream” television is measured. To develop this argument I employ textual and discourse analysis and critical theory, and refer to a range of series produced between 1990 and 2013. These include Twin Peaks (1990-91), The X-Files (1993-2002), The Sopranos (1999-2007), The Wire (2002-2008), Breaking Bad (2008—), Game of Thrones (2011—), Girls (2012—) and House of Cards (2013—). These examples offer an historical range of U.S. television since 1990 with emphasis on developments that I argue have brought quality television to its current visibility.

This thesis examines the earliest science fiction dramas on the BBC, broadcast during the period between 1936 and 1955 when the BBC had the monopoly on television within Britain. These dramas were not originally identified as "science fiction", although their fantastic nature was recognised and provided early television writers and producers the opportunity to engage with social concerns and to experiment with the formal possibilities of the new medium. As the American term "science fiction" became more familiar in Britain after the war, the approaches and responses to these productions changed as the audience responded to the connotations of the genre as well as to the individual programmes, and the BBC had to consider these probable responses with regard to its programming. This coincided with the expansion of the television audience, and the increased possibility of a rival television broadcaster being established. These factors required close consideration with regard to the way that the BBC handled genre on television if it was to successfully adapt to these changing circumstances The dangers of making wrong choices with regard to genre were demonstrated by the controversy surrounding Nineteen Eighty-Four (1954), which connected with concerns over loss of British culture. The benefits of making the right choices regarding genre were shown by the success of Tile Quatermass Experiment (1953). Science fiction production expanded across the BBC, continuing to engage with social concerns, but also helping the BBC to develop a particular identity for its television service based on past successes as it prepared for the arrival of its competitor.

Grapefruit juice is an excellent source of many nutrients and phytochemicals that contribute to a healthy diet. Currently, there is an increasing interest in grapefruit products because consumption appears to be associated with a reduced risk of certain chronic diseases, such as obesity, diabetes, cancers and cardiovascular disease. The consumption of grapefruit (Citrus paradisi Macfadyen) however remains low in South Africa as some individuals like grapefruit and others do not and the reason/s for this variation is not clear. Taste, aroma and colour are important fruit product quality factors that influence consumer preferences. Perception of grapefruit flavour does not depend on only one individual sense, but is the result of multisensory integration of unimodal signals. Where there is a mixture of appearance, taste and aroma signals, cross-modal sensory interaction occurs which may potentially change the intensity and character of flavour perception. Sensory perception is interpreted differently across individuals. The main objective of the study was to determine the effect of varying the bitterness, sweetness, colour and aroma intensities of a grapefruit-like model beverage on the perception of sensory properties and consumer liking of the beverages with the aim of giving guidance to breeders on selection and improvement of grapefruit traits to optimize hedonic value. The second objective of this study was to determine the effects of sensitivity to bitter taste [as determined through 6-propylthiouracil (PROP) taster classification] and genetic variation in TAS2R38 and TAS2R19 SNP genotypes on hedonic rating of the flavour of grapefruit-like beverages differing in bitter/sweet taste intensity. A factorial design was used to formulate 36 grapefruit-like beverages with deflavoured clarified apple juice as base and modification of bitter taste (3 levels), sweet taste (3 levels), aroma intensity (2 levels) and colour (red or yellow). Descriptive analysis was used to describe the sensory profiles of the 36 beverages. Hedonic rating of colour, aroma and flavour of the 12 most diverse beverages from the design was measured with a consumer panel. Sensitivity to bitter taste of 96 young African females (18-24 years) was measure and the respondents classified into PROP taster groups. DNA was extracted from the saliva of the participants for genotyping of TAS2R38 and TAS2R19 bitter receptor genes. The subjects also rated the flavour of grapefruit-like beverages differing in bitter taste intensity for hedonic value. The results showed that varying the bitterness, sweetness, colour and aroma intensity of the grapefruit-like model beverage have an effect on the sensory properties and consumer liking of the beverages. The concentration of naringin in the grapefruit-like beverage increased the bitter taste, aftertaste and grapefruit flavour intensity of the drink. Consumers preferred grapefruit-like beverages with a red colour and low bitterness. Sensitivity to the bitterness of grapefruit beverages and whether there is an association between genetics of bitter taste perception and liking of grapefruit were further explored. The results then showed that respondents’ sensitivity to bitter taste, as well as genetic variation in TAS2R38 and TAS2R19 (single SNP genotypes) are partly responsible for the lower liking of grapefruit model beverages with higher naringin (more bitterness) concentration. In this study, sensitivity of respondents to bitter taste (PROP status) has been linked to preference for red coloured grapefruit beverages, grapefruit beverages with low bitterness/high sweetness and grapefruit-like beverages with low intensity of grapefruit aroma. This is the first study to report on consumers’ perception and acceptance of grapefruit-like model beverages that vary in taste, colour and aroma sensory properties. People differ genetically in bitter taste sensitivity and this research demonstrated the role of some genetic variables (notably rs10772420 of the TAS2R19 SNP genotype and both rs713598 and rs1726866 of the TAS2R38 SNP genotypes). It is the first study showing the effect of TAS2R38 SNP genotypes on grapefruit liking. It is also the first study to determine the effect of PROP taster status, perception of grapefruit beverage characteristics (e.g. bitterness level, colour type and aroma level) and variation in TAS2R38 and TAS2R19 SNP genotypes on hedonic ratings for colour, aroma and flavour of grapefruit-like beverages in a group of South African females. So far populations from Africa have been under represented in similar studies. Most studies where a link between rs10772420 and lower bitterness perception and greater liking for unsweetened grapefruit juice was established, included only Caucasians. Studying the role of genetic differences in sensitivity to PROP bitterness (e.g. in taster status) in modulating multisensory grapefruit flavour perception is needed to determine why the liking for grapefruit varies between individuals. The findings of this study can help researchers and breeders to change properties and traits in grapefruit varieties, can assist product formulators and quality assurance staff to optimize the flavour of grapefruit products for consumer acceptance and to make the generic product more acceptable to a larger portion of the South African population. However, the sample of respondents used in this research represents only a small portion of the South African population and therefore cannot be extrapolated to represent the population. The insights gained from this subgroup may be used to enhance the acceptance of grapefruit products for the larger population.
Thesis (PhD)--University of Pretoria, 2019.
Food Science
PhD
Unrestricted

Soil salinity negatively affects agricultural production in Turkey by decreasing the yield and quality. Direct introduction of stress related genes by genetic engineering is one of the most rapid approaches to develop stress tolerant crops. In this study, TaNHX1 gene was isolated from bread wheat and three different local wheat cultivars were transformed with overexpression vectors containing TaNHX1 gene by using Agrobacterium-mediated and particle bombardment gene transfer techniques. Immature embryo and inflorescence of Triticum durum cv. Kiziltan-91 and Triticum aestivum cv. Yü
regir-89 and mature embryo of Triticum durum cv. Mirzabey-2000 were used as an explant. In this manner, totally 8960 and 5650 explants were used during particle bombardment and Agrobacterium-mediated transformation, respectively. Moreover, leaves of Nicotiana tabacum cv. Petit Havana were transformed by TaSTR gene to develop salt resistant transgenic tobacco plants by using Agrobacterium-mediated transformation. Stable expression and inheritance of the transgenes was confirmed by both genetic and molecular analyses. T1 progeny showed segregation of the transgenes in a typical Mendelian fashion in most of the plants. Expression of TaSTRG in tobacco was evaluated by physiological and biochemical analysis, such as germination test, root length and MDA analysis. In addition to the nuclear transformation, chloroplast transformation of tobacco was performed with Xyl10B gene responsible for the synthesis of hyperthermostable xylanase enzyme. Stable integration of transgenes and homoplasmy were confirmed with PCR and Southern blotting.

2012/2013
Taste has been described as the body's “nutritional gatekeeper”, affecting the identification of nutrients and toxins and guiding food choices. Genetic variation in taste receptor genes can influence perception of sweet, umami and bitter tastes, whereas less is known about the genetics of sour and salty taste. Differences in taste perception, influencing food selection and dietary behavior, have also shown important long-term health implications, especially for food-related diseases such as obesity, diabetes, cardiovascular diseases. To date, a lot of studies are focused on taste receptor genes and function but further investigations are needed to better understand which factors, including genetic ones, are involved in influencing taste and food preferences and the corresponding connections with health status. The aim of this thesis is to understand the genetic bases of taste perception and its relationship to food preferences and health outcomes. Data from ~3500 subjects coming from isolated villages located in Italy, Caucasus and Central Asia were collected. The ability to taste PROP (6-n-propylthiouracil) bitterness and NaCL saltiness, food liking and intake were measured. Additional information such as clinical parameters, professional activity, lifestyle, eating habits and family history were also collected. To learn more about taste biology the following steps were performed in this thesis: 1) genome-wide association studies (GWAS) of bitter and salty taste perception; 2) analysis of the possible impact of bitter taste perception on food preferences; 3) investigation of the relationship between differences in taste perception genes, food preferences and dental caries, as example of health outcome. The main specific results emerging from this PhD thesis work are: 1) GWAS revealed two SNPs closed to TRPV7 and KCNA5 genes associated to salty perception; 2) always through GWAS a SNP closed to GHRL gene, encoding for ghrelin and obestatin, was found to be associated to PROP bitter perception. An additional SNP closed to the 5’ region of the T2R38 gene showed association to the same phenotype; 3) ability to perceive PROP could be a marker for general perception of taste stimuli suggesting that differences in taste perception may be a driver of food liking; 4) the risk to develop dental caries is associated to genetic differences in sweet taste genes. In addition, sweet food liking but not sugar intake results linked to dental caries prevalence, suggesting that food preferences may predictive of health outcomes better than food intake. Overall, these data represent a starting point to better understand how chemosensory differences may interact to influence and predict food choices and human nutritional behavior.
Il gusto può essere considerato il “guardiano alimentare” del corpo, permettendo l’identificazione di sostanze nutritive o tossiche e guidando le scelte alimentari. Variazioni genetiche nei geni che codificano per i recettori del gusto possono influenzare la percezione del gusto dolce, umami e amaro, mentre poco conosciuta è la genetica del gusto acido e salato. Differenze nella percezione gustativa, incidendo sulla scelta del cibo e sul comportamento alimentare, hanno anche mostrato importanti implicazioni a lungo termine per la salute, specialmente per malattie relate alla dieta come l’obesità, il diabete e le malattie cardiovascolari. Finora, molti studi si sono focalizzati sui geni e la funzione dei recettori del gusto, ma ulteriori indagini sono necessarie per comprendere meglio, quali fattori, inclusi quelli genetici, possono influenzare gusto e preferenze alimentari e il corrispondente legame con lo stato di salute. Lo scopo di questa tesi è di comprendere le basi genetiche della percezione del gusto e la sua connessione con le preferenze alimentari e lo stato di salute. Sono stati raccolti dati su ~3500 soggetti provenienti da villaggi isolati situati in Italia, Caucaso e Asia centrale. Sono stati misurati la capacità di percepire l'amarezza del PROP (6-n-propylthiouracile) e il gusto salato del NaCL, le preferenze e i consumi alimentari. Sono stati anche raccolti ulteriori informazioni come parametri clinici , attività professionale, stile di vita, abitudini alimentari e storia familiare. Per comprendere meglio la biologia del gusto in questa tesi sono stati svolti i seguenti steps: 1) studi di associazione su tutto il genoma (GWAS) volti a identificare nuovi geni coinvolti nella percezione del gusto amaro e salato; 2) analisi del possibile impatto della percezione del gusto amaro sulle preferenze alimentari; 3) studio della relazione tra differenze genetiche nella percezione del gusto, preferenze alimentari e carie dentale, come esempio di relazione con lo stato di salute. Le principali scoperte emerse da questa tesi sono: 1) uno studio GWA ha identificato due SNPs vicini ai geni TRPV7 e KCNA5 associati alla percezione del gusto salato; 2) sempre attraverso GWAS uno SNP vicino al gene GHRL, che codifica per la grelina e l’obestatina, è stato trovato associato alla percezione amara del PROP. Un ulteriore SNP localizzato vicino alle regione 5' del gene T2R38 mostra, inoltre, associazione con lo stesso fenotipo PROP; 3) la capacità di percepire il PROP potrebbe essere un marker per la percezione generale degli stimoli gustativi, suggerendo che le differenze nella percezione del gusto possono rappresentare un “driver” del gradimento del cibo; 4) il rischio di sviluppare carie dentali è associato a differenze nei geni che codificano per il gusto dolce. Inoltre, la preferenza per i cibi dolci, ma non il consumo di zuccheri, risulta associata alla prevalenza di carie dentale, suggerendo che le preferenze alimentari possano risultare migliori predittori dello stato di salute rispetto ai consumi alimentari. Complessivamente, questi dati rappresentano un punto di partenza per capire meglio come le differenze chemio-sensoriali possono interagire nell’influenzare e prevedere le scelte alimentari e il comportamento alimentare nell’uomo.
XXVI Ciclo
1983

Ayant remarqué, au cours de mes recherches de master, que questionner les jeunes Françaises sur leur apparence était un outil privilégié pour accéder à des informations concernant le genre et la sexualité, j’ai poursuivi ma recherche pour cette thèse en l’étendant à l’étude des représentations masculines et à la comparaison intergénérationnelle. Cette enquête qualitative s’appuie (notamment) sur un corpus d’une soixantaine d’entretiens individuels avec des hommes et des femmes, que j’ai interrogés sur leurs goûts vestimentaires et leurs opinions concernant l’apparence corporelle.L’enquête a été réalisée à un moment (2011-2015) où l’actualité concernant le genre était brûlante (en pleine polémique sur la « théorie du genre »), ce qui m’a amenée à orienter ma thèse vers une « sociologie de la connaissance » (Berger, Luckmann : 1966) du genre dans le contexte français. Comme l’indique le titre de ma thèse, je considère en effet le vêtement comme un prétexte pour comprendre comment se constituent des groupes hommes et femmes visuellement différenciés, et les liens qu’entretiennent ces apparences différenciées avec l’identification de genre.Dans un chapitre introductif, je décris l’histoire de mon questionnement, ma méthodologie, et enfin mon orientation théorique et épistémologique. Je commence mon argumentation en discutant du contexte historique (chapitres 1) et des modalités de transmission des goûts vestimentaires et des « techniques du corps » (Mauss : 1934) différenciés chez les hommes et les femmes (chapitre 2). Puis, j’aborde la construction identitaire comme un mécanisme amplifiant et naturalisant des différences (chapitre 3). J’en arrive à analyser certains propos abordant la question de la hiérarchie de genre, ainsi que des pratiques vestimentaires qui se proposent de subvertir cette hiérarchie (chapitre 4). Je termine en discutant du point de vue d’individus qui restent attachés à l’amplification de la différence des sexes au moyen de symboles (chapitre 5)
In the course of my previous research, I realized that asking young French women about their body appearance was an interesting way to gather information regarding gender and sexuality. For this thesis, I generalized the analysis of the opinions about appearance and clothes, adding men’s opinions and an intergenerational comparison.This qualitative investigation is based on sixty interviews with men and women, who have been interviewed about their clothing tastes and opinions regarding body appearance. I carried out this study in the political context of the vote on the same-sex marriage law, at a moment (2011-2015) when the “gender topic” was sensitive. This led me to direct my research towards a “sociology of knowledge” (Berger, Luckmann: 1966) of gender in the French context.As indicated in the title of the thesis, I indeed consider the thematic “clothes” as a pretext to understand how visually differentiated groups of men and women are created, and the links between those differentiated appearances and the gender identification.Introduction sets out how I came to study this question, the methodology used, the theoretical and epistemological orientation. Chapter 1 describes the historical context of women’s and men’s different preferences in terms of choice of clothes. Then, in chapter 2, I try to explain the modalities through which taste in clothes and the associated “techniques of the body” (Mauss: 1934) are transmitted. Chapter 3 focuses on the construction of identity as a mechanism which accentuates and naturalizes the differences. Chapter 4 analyzes opinions concerning gender hierarchy and some way of dressing that aim at subverting this hierarchy. I finally discuss the point of view of those who attach an importance to the symbolic accentuation of sex differences in chapter 5

INTRODUÇÃO: A obesidade infantil é um importante problema de saúde pública e apresenta impacto direto na qualidade de vida das crianças e adolescentes, bem como no desenvolvimento futuro de doenças crônicas. O padrão alimentar rico em gordura e açúcar, e com baixo aporte de fibra dietética, vitaminas e minerais é reconhecido como fator de risco para o surgimento da obesidade, no entanto os fatores que contribuem para a preferência por alimentos ricos nestes nutrientes não são bem estabelecidos. O sabor dos alimentos é reconhecido como um importante preditor das escolhas alimentares, e os polimorfismos nos genes que codificam os receptores do sabor podem explicar a variabilidade da preferência e consumo alimentar na população. OBJETIVO: Avaliar a influência de polimorfismos de genes de receptores de sabor gorduroso (CD36), doce (TAS1R2) e amargo (TAS2R38) no consumo alimentar e no perfil metabólico de crianças e adolescentes obesos. MÉTODOS: Estudo transversal com 668 crianças e adolescentes obesos e um grupo controle de 135 crianças eutróficas, de ambos os gêneros. Foi realizado o estudo molecular dos polimorfismos de nucleotídeo único (SNPs) rs1761667 e rs1527483 do CD36, rs9701796 e rs35874116 do TAS1R2, e rs1726866 e rs713598 do TAS2R38, bem como análise do consumo alimentar e perfil metabólico. RESULTADOS: Em relação ao CD36, o alelo A do rs1761667 relacionou-se com menor consumo de lipídios totais, gorduras poli e monoinsaturadas, consumo de alimentos de sabor gorduroso, ingestão de óleos vegetais e açúcares totais em obesos. O alelo A do rs1527483 associou-se com menor percentil de pressão arterial diastólica, menor massa gorda e maior massa livre de gordura em obesos. Quanto ao gene TAS1R2, a variante rs9701796 teve maior risco metabólico segundo a razão circunferência da cintura-estatura (RCE), bem como relação com maior consumo de achocolatado em pó em obesos. Já a variante rs35874116 mostrou relação com a menor ingestão de fibras dietéticas em obesos. No TAS2R38, o alelo G do rs1726866 foi associado com menor consumo de gorduras monoinsaturadas e maior consumo de açúcares totais, em obesos. O alelo G do rs713598 mostrou relação com maior consumo de carboidratos, consumo de alimentos de sabor doce, refrigerantes e menor ingestão de fibras pelos indivíduos eutróficos. CONCLUSÃO: Não houve relação entre genótipos e risco de obesidade. Os achados mostram a associação entre polimorfismos dos genes de receptores de sabor com o consumo alimentar, indicando diferenças entre obesos e magros, e alelos de proteção e de risco cardiometabólico, respectivamente dos genes CD36 e TAS1R2
BACKGROUND: Childhood obesity is a major public health problem and it has a direct impact on the quality of life of children and adolescents, as well as the future risk for development of chronic diseases. The dietary pattern rich in fats and sugars associated to the low intake of dietary fibers, vitamins and minerals is widespread for the rise of obesity. However the factors that contribute to the preference for foods rich in these nutrients are not well established. Taste is recognized as an important predictor of food choices, and polymorphisms in genes encoding its receptors may explain the variability of taste preference and food intake on population. OBJECTIVE: To evaluate the influence of polymorphisms of fat (CD36), sweet (TAS1R2) and bitter (TAS2R38) taste receptor genes in diet and metabolic profile in obese children and adolescents. METHODS: Cross-sectional study with 668 obese children and adolescents and a control group of 135 normal-weight children. The molecular study was made for single nucleotide polymorphisms (SNPs) rs1761667 and rs1527483 of CD36, rs9701796 and rs35874116 of TAS1R2, rs1726866 and rs713598 of TAS2R38, and the analysis of food intake and metabolic profile. RESULTS: In relation to CD36, the A allele of rs1761667 was associated with lower intake of total fat, poly and monounsaturated fats, consumption of fatty flavor food, intake of vegetable oils and total sugars in obese. The A allele of rs1527483 was associated with lower percentile of diastolic blood pressure, lower fat mass and increased fat-free mass in obese. Regarding TAS1R2 gene, the variant rs9701796 was associated to increased metabolic risk according to waist-height ratio, as well as with higher consumption of chocolate powder in obese. The variant rs35874116 showed a lower intake of dietary fiber. In TAS2R38, the G allele of rs1726866 was associated with a lower intake of monounsaturated fat and a higher intake of total sugars in obese. The G allele of rs713598 was related to the higher carbohydrate intake, consumption of sweet tasting food, soda drinks and less fiber intake by normal weight children. CONCLUSION: There was no relationship between genotypes and risk of obesity. The findings show the association between polymorphisms of taste receptor genes with dietary intake, indicating differences between obese and lean children, as well as the protective and risk alleles for cardiometabolic risk in CD36 and TAS1R2, respectively

The aim of this master’s thesis is to examine how Swedish public libraries approach and regard lesbian pulp fiction as a genre, from both a historical and modern perspective, and also to visualize and critique the surrounding discourses that influence the perception and reception of the genre. The method is twofold and consists of qualitative interviews as well as discourse analysis inspired by Foucault. The data consists of interviews with three librarians responsible for library collections, selection and purchase of new library materials which is combined with a survey reading of Biblioteksbladet, the periodical of Svensk Biblioteksförening, from 1945–1990. Michel Foucaults theories on discourses and the principles and mechanisms of exclusion, and Pierre Bourdieus theories on taste and distinction, guide the analysis. The analysis focuses to a great extent on discursive patterns, especially concerning the relationship between popular and quality fiction, and components of Bourdieus field theory and how this contributes to the creation of taste through distinction. Throughout the analysis possible explanations regarding the position of lesbian pulp fiction are given which covers areas from classification and interpretation of literary genres to quality assessment, selection and purchase of literature. The results of the study shows that lesbian pulp fiction is quite invisible in Swedish public libraries which is mainly seen as an effect of discursive practices that surround and influence the genre such as the societal and historical view of homosexuality but also the view on popular literature. Conclusions are that librarians are not making conscious exclusions of lesbian pulp fiction per se, they are if anything quite unaware of the genre’s existence, but that the practices that shape the field of public libraries has contributed to the genre’s position. The study is a two years master’s thesis in Library and Information Science written at Uppsala university.

A pesquisa para a elaboração da tese \"Gosto ou Licença? Como interpretar as suite sonates de Jacques Martin Hotteterre - Le Romain (1674-1763) através da flauta doce\" teve por finalidade investigar se a forma híbrida da música instrumental europeia - suite sonate [suitte sonate] do compositor francês setecentista - foi um exemplo precursor do gênero que conhecemos como gostos reunidos. Os objetos estudados são de fundamental importância, pois no século XVIII fomentaram a criação de um novo estilo musical nacional, o estilo alemão. Para tal contextualização, foi necessária a busca pelos significados dos termos \'gosto\', \'gênio\', \'maneira\', \'estilo\' e \'licença\', relacionados ao conceito de imitação da natureza nas artes setecentistas através da fundamentação teórica de Charles Batteux (1713-1780), apresentando neste texto uma teoria do percurso do termo \'gosto\'. Essa transformação do termo \'gosto\' está presente tanto no âmbito da criação da obra quanto no da execução - interpretação da prática musical do período barroco. Por essa razão, esse texto avalia os elementos cabíveis a uma interpretação atual de um texto musical setecentista. Dessa forma, além dos conceitos teóricos e práticos, será possível conhecer também a grande contribuição do flautista e compositor francês para a sua arte, como sua preocupação didática em seu tratado, em seu manual, além de seu cuidado não usual de prover informações de execução em suas partituras; sua expressiva e repleta de licenças música de câmara; sua inventividade na reunião de dois estilos musicais setecentistas; e sua responsabilidade nas mudanças da técnica flautística da época.
The research for writing this dissertation, titled \"Taste and Licence? How to interpret the Jacques Martin Hotteterre - Le Romain (1674-1763) sonates on the recorder\", was meant to investigate whether a hybrid European instrumental music form - suite sonate [suitte sonate] by the eighteenth century composer - was a forerunner example of the genre we know as Reunited Styles. The objects studied herein have great importance, because they promoted a new musical style created in the eighteenth century, the German style. For such context, it was necessary to investigate the meanings of terms such as \'taste\', \'genius\', \'manner\', \'style\', and \'license\', related to the seventeenth century arts\' concept of imitation of nature, as per the theoretical fundaments by Charles Batteux (1713-1780). A theory about the course of the term \'taste\' is presented in this dissertation. Such transformation of that term can be found both in the creation of the musical work and in its execution - baroque music historically informed performance. For the aforementioned reasons, this dissertation assesses the appropriate elements necessary for a contemporary interpretation of an eighteenth century musical text. Thus, besides the theoretical and practical concepts, it will be possible to know the French composer and flautist\'s greatest contribution to his art: the didactic concerns in his treatise, in his practical guide, as well as having the unusual care to provide performance information in his scores; his chamber music, so expressive and filled with licenses; his resourcefulness when uniting two eighteenth century musical styles and his part in the flute technique changes in that time

Les principaux objets étudiés dans cette thèse sont les équations décrivant le morphisme de groupe sur une variété abélienne, plongée dans un espace projectif, et leurs applications en cryptographie. Notons g sa dimension et k son corps de définition. Ce mémoire est composé de deux parties. La première porte sur l'étude des courbes d'Edwards, un modèle pour les courbes elliptiques possédant un sous-groupe de points k-rationnels cyclique d'ordre 4, connues en cryptographie pour l'efficacité de leur loi d'addition et la possibilité qu'elle soit définie pour toute paire de points k-rationnels (loi d'addition k-complète). Nous en donnons une interprétation géométrique et en déduisons des formules explicites pour le calcul du couplage de Tate réduit sur courbes d'Edwards tordues, dont l'efficacité rivalise avec les modèles elliptiques couramment utilisés. Cette partie se conclut par la génération, spécifique au calcul de couplages, de courbes d'Edwards dont les tailles correspondent aux standards cryptographiques actuellement en vigueur. Dans la seconde partie nous nous intéressons à la notion de complétude introduite ci-dessus. Cette propriété est cryptographiquement importante car elle permet d'éviter des attaques physiques, comme les attaques par canaux cachés, sur des cryptosystèmes basés sur les courbes elliptiques ou hyperelliptiques. Un précédent travail de Lange et Ruppert, basé sur la cohomologie des fibrés en droite, permet une approche théorique des lois d'addition. Nous présentons trois résultats importants : tout d'abord nous généralisons un résultat de Bosma et Lenstra en démontrant que le morphisme de groupe ne peut être décrit par strictement moins de g+1 lois d'addition sur la clôture algébrique de k. Ensuite nous démontrons que si le groupe de Galois absolu de k est infini, alors toute variété abélienne peut être plongée dans un espace projectif de manière à ce qu'il existe une loi d'addition k-complète. De plus, l'utilisation des variétés abéliennes nous limitant à celles de dimension un ou deux, nous démontrons qu'une telle loi existe pour leur plongement projectif usuel. Finalement, nous développons un algorithme, basé sur la théorie des fonctions thêta, calculant celle-ci dans P^15 sur la jacobienne d'une courbe de genre deux donnée par sa forme de Rosenhain. Il est désormais intégré au package AVIsogenies de Magma
The main objects we study in this PhD thesis are the equations describing the group morphism on an abelian variety, embedded in a projective space, and their applications in cryptograhy. We denote by g its dimension and k its field of definition. This thesis is built in two parts. The first one is concerned by the study of Edwards curves, a model for elliptic curves having a cyclic subgroup of k-rational points of order 4, known in cryptography for the efficiency of their addition law and the fact that it can be defined for any couple of k-rational points (k-complete addition law). We give the corresponding geometric interpretation and deduce explicit formulae to calculate the reduced Tate pairing on twisted Edwards curves, whose efficiency compete with currently used elliptic models. The part ends with the generation, specific to pairing computation, of Edwards curves with today's cryptographic standard sizes. In the second part, we are interested in the notion of completeness introduced above. This property is cryptographically significant, indeed it permits to avoid physical attacks as side channel attacks, on elliptic -- or hyperelliptic -- curves cryptosystems. A preceeding work of Lange and Ruppert, based on cohomology of line bundles, brings a theoretic approach of addition laws. We present three important results: first of all we generalize a result of Bosma and Lenstra by proving that the group morphism can not be described by less than g+1 addition laws on the algebraic closure of k. Next, we prove that if the absolute Galois group of k is infinite, then any abelian variety can be projectively embedded together with a k-complete addition law. Moreover, a cryptographic use of abelian varieties restricting us to the dimension one and two cases, we prove that such a law exists for their classical projective embedding. Finally, we develop an algorithm, based on the theory of theta functions, computing this addition law in P^15 on the Jacobian of a genus two curve given in Rosenhain form. It is now included in AVIsogenies, a Magma package

Gustation, also known as taste perception, is critical for the survival of most animal species. The fruit fly Drosophila melanogaster employs 68 different gustatory receptors (GRs) for the detection of sugars, bitter or toxic compounds, and pheromones. However, with a few notable exceptions, the functions of most GRs involved in feeding are unknown. Our research has focused on a cluster of highly-related Drosophila Grs, known as the Gr64 family, that have been shown to be critical for the perception of multiple sugars. Furthermore, we have demonstrated that another gene related to the Gr64 genes, Gr61a, is a sugar receptor that is narrowly tuned to a subset of pyranose sugars and may (along with the Gr64 genes) be indispensable for early fly development.

As a complementary approach to our behavioral analysis, we have examined the expression pattern of the Drosophila sugar receptors using knock-in driver alleles created by homologous recombination. As expected, most of these drivers have shown strong expression in various taste tissues. Intriguingly, some of these knock-in alleles also show expression in the maxillary palp and antenna, tissues previously thought to be involved only in olfaction. These expression patterns raise interesting questions about the true range of function of these chemosensory receptors and whether or not they might be involved in olfaction as well as gustation.

Dissertation

The topic of my diploma thesis is how listeners of metal identify themselves with metal as a music genre and which form of colectivity they generate on the basis of their common musical taste. At first I introduce a short history and development of metal music and then I characterize the concepts of social sciences, that deals with the study of musical cultures and also the concepts of subcultural capital and identity, which I use in my work. The main part of my work constitutes an interpretation of data from my research between metalists, which took place on metal concerts in Prague and on metal festivals in the Czech Republic in the form of participant observation and half-structured and non-formal interviews with listeners of this genre. My research ascertained what does it mean to be a metalist, how important part of life metal represents for its listeners, which shared attitudes and values metal generates, what produces the sense of belonging of metalists and if there is any inner division between them.