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Polimorfismos de nucleotídeo único afetam a predição de alvos de microRNAs em bovinos /Sousa, Marco Antonio Perpétuo de January 2019 (has links)
Orientador: Flávia Lombardi Lopes / Resumo: O melhoramento genético em bovinos visa a seleção de características para facilitar o manejo, a qualidade da carne, a resistência a doenças e a adaptação ao meio ambiente. Polimorfismos de nucleotídeo único (SNPs) podem gerar grandes efeitos sobre essas características fenotípicas. Os microRNAs são pequenos RNAs não-codificadores que atuam como reguladores da expressão pós-transcricional através de sua ligação a mRNAs alvo. No presente estudo, realizamos o cruzamento de dados entre ~56 milhões de SNPs contra todas as seqüências conhecidas de miRNA bovino e analisamos in silico, seus possíveis efeitos. Seguindo a predição dos alvos, mostramos que 82% dos alvos foram alterados como consequência dos SNPs que ocorrem na região de seed de miRNAs maduros. Em seguida, identificamos variações na Energia Livre Mínima (MFE) que representam a capacidade de alterar a estabilidade das moléculas e, consequentemente, a maturação dos miRNAs. Também encontramos 129 SNPs em miRNAs, que alteraram sua predição com alvos, ocorrendo em regiões de QTL e, por último, a análise dos escores de conservação evolutiva para cada locus de SNP sugeriu que eles têm uma função biológica conservada através do processo evolutivo. Nossos resultados sugerem que os SNPs em microRNAs têm o potencial de alterar os fenótipos bovinos e são de grande valor para a pesquisa de melhoramento genético, bem como para a produção. / Abstract: Genetic improvement of cattle is aimed at selection of characteristics to facilitate the handling, quality of the meat, resistance to diseases and adaptation to the environment. Single nucleotide polymorphisms (SNPs) can generate large effects on these phenotypic characteristics. MicroRNAs are small non-coding RNAs that act as regulators of posttranscriptional expression through their binding to target mRNAs. In the present study, we scanned ~56 million SNPs against all known bovine miRNA sequences and analyzed in silico, their possible effects. Following target prediction, we show that 82% of targets were altered as a consequence of SNPs that occur in the seed region of mature miRNAs. Next, we identified variations in the Minimum Free Energy (MFE) which represent the capacity to alter molecule stability and, consequently, the maturation of the miRNAs. We have also found 129 SNPs in miRNAs, with altered target prediction, occurring in QTL regions and, lastly, analysis of evolutionary conservation scores for each SNP locus suggested that they have a conserved biological function through the evolutionary process. Our results suggest that SNPs in microRNAs have the potential to alter bovine phenotypes and are of great value for genetic improvement research, as well as production. / Mestre
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Ansiedade na performance musical: estudo molecular de associação e validação da escala de \"K-MPAI / Music performance anxiety: molecular Association Study and Validation of the K-MPAI ScaleRocha, Sergio de Figueiredo 02 March 2012 (has links)
A performance musical requer um alto nível de habilidade em diversos parâmetros como coordenação motora, atenção e memória, o que a torna uma atividade particularmente susceptível aos estados de ansiedade. Pesquisas nessa área têm avançado com a introdução de instrumentos específicos para abordar a ansiedade na performance musical (MPA), como é o caso da the Kenny Music Performance Anxiety Inventory (K-MPAI). Estudos recentes apontam polimorfismos genéticos envolvidos na base do quadro de ansiedade os quais já foram descritos no genoma humano e avaliados em pacientes com autismo, ataque de pânico e na depressão. No entanto, não existia na literatura mundial qualquer estudo relacionando polimorfismos de DNA e MPA. O presente estudo teve duas fases. A primeira fase, com objetivo traduzir, adaptar e validar a K-MPAI para a língua portuguesa e a segunda fase, o objetivo foi avaliar polimorfismos genéticos possivelmente associados à MPA. Após a autorização da autora, a escala KMPAI foi traduzida e validada. A escala em língua portuguesa foi aplicada a 218 músicos de ambos os sexos, amadores e profissionais. Para a validação concorrente, foi utilizado o Inventário de Ansiedade Traço-Estado (IDATE), versão validada na língua portuguesa da State Trait Anxiety Inventory (STAI). A análise da consistência interna apresentou alfa de Cronbach=0.957 com p<0.001, reprodutibilidade com p=0.378 e validação concorrente com a IDATE com alfa de Cronbach=0.642 e p<0.001. O estudo de validação permitiu considerar a amostra com graus de confiabilidade e reprodutibilidade elevados, o que traduz este estudo como provindo de uma amostra não tendenciada e replicável a outras populações. A validação concorrente entre a K-MPAI e a IDATE permite inferir que ambas são comparáveis na capacidade de medir os níveis de MPA. Na segunda fase, foi analisada a associação entre polimorfismos dos genes GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) e TMEM132D (rs900256) e o quadro de MPA. Após a aplicação da escala K-MPAI em 307 músicos (197 homens e 110 mulheres) amostras de sangue periférico foram coletadas de dos 80 sujeitos das extremidades da curva de distribuição de scores da K-MPAI (35 homens e 45 mulheres), sendo seu DNA usado para genotipagens. Análises das freqüências genotípicas e alélicas não evidenciaram diferenças estatisticamente significativas entre os grupos polares, muito embora tendências à significância fossem observadas em alguns casos, quando os gêneros foram avaliados separadamente, sugerindo que mais indivíduos devam ser analisados. A detecção de polimorfismos de DNA associados à MPA poderá permitir uma melhor compreensão dos mecanismos moleculares associados a este quadro que também ocorre em outras situações de exposição em diversas áreas de atuação. Além disso, futuros estudos poderão permitir delinear exames prognósticos e diagnósticos mais precisos, levando a um melhor conhecimento da origem da MPA / Music performance requires high levels of ability in parameters such as coordination, attention and memory, which makes it particularly susceptible to anxiety states. Scales were recently developed to evaluate and quantify music performance anxiety (MPA). However, although we are able to measure MPA, biomarkers for this condition are not available and its biological basis has not been established. On the first part of this work, we translated, adapted and validated the K-MPAI to Portuguese, generating the first MPA evaluation instrument in the language. After authorization from the author, the K-MPAI scale was translated and validated. The scale in the Portuguese language was applied to 218 musicians of both genders, professionals and amateurs. For the concurrent validation, the IDATE inventory, a validated version of the STAI Inventory (State Trait Anxiety Inventory) was used. Consistency analyses showed Cronbach\'s alpha=0.957 with p<0.001, reproducibility with p=0.378 and concurrent validation with IDATE with Cronbach\'s alpha=0.642 and p<0.001. The validation study allowed the samples to be considered with high degrees of certainty and reproducibility, which shows that this study is based on an unbiased sample and can be replicable to other populations. On the second part of this work, we strived to contribute to the knowledge of the biological basis of MPA, validating and analyzing the frequency of DNA polymorphisms possibly associated to this condition. We searched for genes that could be involved with the anxiety processes and evaluated the polymorphisms with higher frequency and/or more capacity of causing functional alterations. The genes and the polymorphisms selected (presented with their identification codes in the dbSNP database) were: GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) and TMEM132D (rs900256). The status of these polymorphisms was determined in a process of selective genotyping, from a group of 80 subjects who had the higher and lower scores in the distribution curve of the K-MPAI scores (derivating from a total of 307 musicians, having scores deviating at least 1 standard deviation in average). Tests for these polymorphisms were designed, validated and evaluated with the DNA of these 80 subjects. Analysis of the allelic and genotypic frequencies of these polymorphisms did not show associations that were statistically significant. Tendencies to significance were observed when analyses were conducted separately in each gender, suggesting that studies with higher sample size should be performed. The study of genetic polymorphisms associated to MPA has the potential for contributing to a better understanding of the biological basis of anxiety
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Ansiedade na performance musical: estudo molecular de associação e validação da escala de \"K-MPAI / Music performance anxiety: molecular Association Study and Validation of the K-MPAI ScaleSergio de Figueiredo Rocha 02 March 2012 (has links)
A performance musical requer um alto nível de habilidade em diversos parâmetros como coordenação motora, atenção e memória, o que a torna uma atividade particularmente susceptível aos estados de ansiedade. Pesquisas nessa área têm avançado com a introdução de instrumentos específicos para abordar a ansiedade na performance musical (MPA), como é o caso da the Kenny Music Performance Anxiety Inventory (K-MPAI). Estudos recentes apontam polimorfismos genéticos envolvidos na base do quadro de ansiedade os quais já foram descritos no genoma humano e avaliados em pacientes com autismo, ataque de pânico e na depressão. No entanto, não existia na literatura mundial qualquer estudo relacionando polimorfismos de DNA e MPA. O presente estudo teve duas fases. A primeira fase, com objetivo traduzir, adaptar e validar a K-MPAI para a língua portuguesa e a segunda fase, o objetivo foi avaliar polimorfismos genéticos possivelmente associados à MPA. Após a autorização da autora, a escala KMPAI foi traduzida e validada. A escala em língua portuguesa foi aplicada a 218 músicos de ambos os sexos, amadores e profissionais. Para a validação concorrente, foi utilizado o Inventário de Ansiedade Traço-Estado (IDATE), versão validada na língua portuguesa da State Trait Anxiety Inventory (STAI). A análise da consistência interna apresentou alfa de Cronbach=0.957 com p<0.001, reprodutibilidade com p=0.378 e validação concorrente com a IDATE com alfa de Cronbach=0.642 e p<0.001. O estudo de validação permitiu considerar a amostra com graus de confiabilidade e reprodutibilidade elevados, o que traduz este estudo como provindo de uma amostra não tendenciada e replicável a outras populações. A validação concorrente entre a K-MPAI e a IDATE permite inferir que ambas são comparáveis na capacidade de medir os níveis de MPA. Na segunda fase, foi analisada a associação entre polimorfismos dos genes GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) e TMEM132D (rs900256) e o quadro de MPA. Após a aplicação da escala K-MPAI em 307 músicos (197 homens e 110 mulheres) amostras de sangue periférico foram coletadas de dos 80 sujeitos das extremidades da curva de distribuição de scores da K-MPAI (35 homens e 45 mulheres), sendo seu DNA usado para genotipagens. Análises das freqüências genotípicas e alélicas não evidenciaram diferenças estatisticamente significativas entre os grupos polares, muito embora tendências à significância fossem observadas em alguns casos, quando os gêneros foram avaliados separadamente, sugerindo que mais indivíduos devam ser analisados. A detecção de polimorfismos de DNA associados à MPA poderá permitir uma melhor compreensão dos mecanismos moleculares associados a este quadro que também ocorre em outras situações de exposição em diversas áreas de atuação. Além disso, futuros estudos poderão permitir delinear exames prognósticos e diagnósticos mais precisos, levando a um melhor conhecimento da origem da MPA / Music performance requires high levels of ability in parameters such as coordination, attention and memory, which makes it particularly susceptible to anxiety states. Scales were recently developed to evaluate and quantify music performance anxiety (MPA). However, although we are able to measure MPA, biomarkers for this condition are not available and its biological basis has not been established. On the first part of this work, we translated, adapted and validated the K-MPAI to Portuguese, generating the first MPA evaluation instrument in the language. After authorization from the author, the K-MPAI scale was translated and validated. The scale in the Portuguese language was applied to 218 musicians of both genders, professionals and amateurs. For the concurrent validation, the IDATE inventory, a validated version of the STAI Inventory (State Trait Anxiety Inventory) was used. Consistency analyses showed Cronbach\'s alpha=0.957 with p<0.001, reproducibility with p=0.378 and concurrent validation with IDATE with Cronbach\'s alpha=0.642 and p<0.001. The validation study allowed the samples to be considered with high degrees of certainty and reproducibility, which shows that this study is based on an unbiased sample and can be replicable to other populations. On the second part of this work, we strived to contribute to the knowledge of the biological basis of MPA, validating and analyzing the frequency of DNA polymorphisms possibly associated to this condition. We searched for genes that could be involved with the anxiety processes and evaluated the polymorphisms with higher frequency and/or more capacity of causing functional alterations. The genes and the polymorphisms selected (presented with their identification codes in the dbSNP database) were: GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) and TMEM132D (rs900256). The status of these polymorphisms was determined in a process of selective genotyping, from a group of 80 subjects who had the higher and lower scores in the distribution curve of the K-MPAI scores (derivating from a total of 307 musicians, having scores deviating at least 1 standard deviation in average). Tests for these polymorphisms were designed, validated and evaluated with the DNA of these 80 subjects. Analysis of the allelic and genotypic frequencies of these polymorphisms did not show associations that were statistically significant. Tendencies to significance were observed when analyses were conducted separately in each gender, suggesting that studies with higher sample size should be performed. The study of genetic polymorphisms associated to MPA has the potential for contributing to a better understanding of the biological basis of anxiety
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Development of a COMT PCR multiplex to investigate resilience, anxiety and childhood trauma in a South African populationJacobs, Sarah January 2020 (has links)
>Magister Scientiae - MSc / Anxiety, resilience and childhood trauma can be categorized as functional behavioural categories, with a wealth of research behind each. The research approach adopted for each, in most cases, is either from a genetic or neuropsychological standpoint, with few studies combining both to better understand all three functional behavioural categories as a multidimensional construct A number of candidate genes have been identified as markers for anxiety, resilience and childhood trauma, of which Catechol-methyl-transferase (COMT) and several respective single nucleotide polymorphisms (SNPs) are included. Although COMT SNPs have been linked to at least one of the functional categories, with a handful of haplotypes identified, to our knowledge no study has investigated the combination of SNPs selected for this study (rs6269, rs4818, rs4680, rs4633, rs737865, rs2075507) as a possible haplotype, specifically in a South African population. The use of SNaPshot for the genotyping of genes is an efficient and reliable means of identifying genotype frequencies and haplotypes in large sample groups, yet when selecting more than two SNPs of interest, the development of a multiplex assay is ideal. The first aim of the study was to design and optimize a multiplex assay to genotype several COMT SNPs. The primer design, multiplex optimization and SNaPshot conditions used showed good working parameters that can be utilized and further improved by optimization. Self-report measures are widely used to measure psychiatric disorders, such as anxiety, and has also been used for the measurement of resilience and childhood trauma. With each functional behavioural category well investigated in its respective domain, there is a need to investigate all three as a collective in a South African population due to the high rate of anxiety and childhood trauma exposure in communities. The second aim of the study was to investigate the prevalence of anxiety, resilience and childhood as functional behavioural categories in the full South African sample group; and the role of sex, through established self-report measures and respective normative data. Additionally, this carried over into investigating the correlation between anxiety, resilience and childhood trauma as a multidimensional construct in both the full South African sample and between sexes. There is a clear relationship which exists between all three functional behavioural categories, as they show a correlation in various dimensions
independent of one another. Higher anxiety levels amongst females were reported, with no difference between sexes for resiliency. The empirical data collected from both COMT SNP and self-report measures for male and female where explored and reviewed against current literature for better understanding and insight into the association of COMT SNPs with anxiety, resilience and childhood trauma in a
South African population. The results of this study to understand the complexity and association of all three functional behavioural categories as a multidimensional construct will be invaluable and may assist in the identification of possible risk factors which are essential
for the promotion of better mental health in society.
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Aneuploidy: Using genetic instability to preserve a haploid genome?Ramdath, Ramona Sherry 14 July 2009 (has links)
No description available.
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Σχεδιασμός, υλοποίηση και εφαρμογή μεθόδων υπολογιστικής νοημοσύνης για την πρόβλεψη παθογόνων μονονουκλεοτιδικών πολυμορφισμώνΡαπακούλια, Τρισεύγενη 11 October 2013 (has links)
Η πιο απλή μορφή γενετικής διαφοροποίησης στον άνθρωπο είναι οι μονονουκλεοτιδικοί πολυμορφισμοί (Single Nucleotide Polymorphisms - SNPs). Ο αριθμός αυτού του είδους πολυμορφισμών που έχουν βρεθεί στο ανθρώπινο γονιδίωμα και επηρεάζουν την παραγόμενη πρωτεΐνη αυξάνεται συνεχώς, αλλά η αντιστοίχηση τους σε πιθανές ασθένειες με πειραματικές μεθόδους είναι ασύμφορη από θέμα χρόνου και κόστους. Για αυτό τον λόγο έχουν αναπτυχθεί διάφορες υπολογιστικές μέθοδοι με σκοπό να ταξινομήσουν τους μονονουκλεοτιδικούς πολυμορφισμούς σε παθογόνους και μη. Οι περισσότερες από αυτές τις μεθόδους χρησιμοποιούν ταξινομητές, οι οποίοι παίρνοντας σαν είσοδο ένα σύνολο δομικών, λειτουργικών, ακολουθιακών και εξελικτικών χαρακτηριστικών, επιχειρούν να προβλέψουν αν ένας μονονουκλεοτιδικός πολυμορφισμός είναι παθογόνος ή μη. Για την εκπαίδευση αυτών των ταξινομητών, χρησιμοποιούνται δύο σύνολα μονονουκλεοτιδικών πολυμορφισμών. Το πρώτο αποτελείται από μονονουκλεοτιδικούς πολυμορφισμούς που έχει βρεθεί πειραματικά ότι οδηγούν σε παθογένεια και το δεύτερο από μονονουκλεοτιδικούς πολυμορφισμούς που έχει αποδειχθεί πειραματικά ότι είναι αδρανείς. Οι μέθοδοι αυτές διαφέρουν στα χαρακτηριστικά των μεταλλάξεων που λαμβάνουν υπόψη στην πρόβλεψη τους, καθώς επίσης και στην εκπαίδευση και τη φύση των τεχνικών ταξινόμησης, που χρησιμοποιούν για τη λήψη των αποφάσεων. Το βασικότερο προβλήματα τους ωστόσο έγκειται στο γεγονός ότι καθορίζουν τα χαρακτηριστικά, που θα χρησιμοποιήσουν σαν είσοδο στους ταξινομητές τους με τρόπο εμπειρικό και μάλιστα διαφορετικές μέθοδοι προτείνουν και χρησιμοποιούν διαφορετικά χαρακτηριστικά, χωρίς να τεκμηριώνουν επαρκώς τις αιτίες αυτής της διαφοροποίησης. Δύο ακόμα προβλήματα που δεν έχουν καταφέρει να αντιμετωπίσουν οι υπάρχουσες μεθοδολογίες είναι το πρόβλημα της ανισορροπίας των δύο κλάσεων ταξινόμησης και των ελλιπών τιμών σε πολλά από τα χαρακτηριστικά εισόδου των ταξινομητών, ώστε να επιτυγχάνουν πιο ακριβή και αξιόπιστα αποτελέσματα. Από τα παραπάνω είναι ξεκάθαρο πως υπάρχει μεγάλο περιθώριο βελτίωσης των υπάρχουσων μεθοδολογιών για το συγκεκριμένο πρόβλημα ταξινόμησης.
Στην παρούσα διπλωματική εργασία προτείνουμε μια νέα υβριδική μεθοδολογία υπολογιστικής νοημοσύνης, που ξεπερνά πολλά από τα προβλήματα των υπάρχοντων μεθοδολογιών και βελτιώνει με τον τρόπο αυτό την απόδοσή τους. Δύο είναι τα βασικά βήματα που ακολουθήσαμε για την επίτευξη του στόχου αυτού. Πρώτον, συγκεντρώσαμε από τις διαθέσιμες δημόσιες βάσεις δεδομένων, τους μονονουκλεοτιδικούς πολυμορφισμούς που χρησιμοποιήθηκαν για την εκπαίδευση και τον έλεγχο των μοντέλων μηχανικής μάθησης. Συγκεκριμένα, συλλέχθησαν και φιλτραρίστηκαν τα θετικά και αρνητικά σύνολα εκπαίδευσης και ελέγχου, που αποτελούνται από μονονουκλεοτιδικούς πολυμορφισμούς που είτε οδηγούν σε παθογένεια, είτε είναι ουδέτεροι. Για κάθε πολυμορφισμό των δύο συνόλων υπολογίσαμε χρησιμοποιώντας υπάρχοντα διαθέσιμα εργαλεία όσο το δυνατό περισσότερα δομικά, λειτουργικά, ακολουθιακά και εξελικτικά χαρακτηριστικά. Για εκείνα τα χαρακτηριστικά, για τα οποία δεν υπήρχε κάποιο διαθέσιμο εργαλείο υπολογισμού τους, υλοποιήσαμε τον κατάλληλο κώδικα για τον υπολογισμό τους.
Το δεύτερο βήμα της διπλωματικής αφορούσε το σχεδιασμό και την υλοποίηση της κατάλληλης υβριδικής μεθόδου για την επίλυση του προβλήματος που μελετάμε. Χρησιμοποιήσαμε μια νέα μέθοδο ταξινόμησης την EnsembleGASVR. Πρόκειται για μια ensemble μεθοδολογία, που συνδυάζει σε ένα ενιαίο πλαίσιο ταξινόμησης οκτώ διαφορετικούς ταξινομητές. Κάθε ένας από αυτούς τους ταξινομητές βασίζεται στον υβριδικό συνδυασμό των Γενετικών Αλγορίθμων και των μοντέλων Παλινδρόμησης Διανυσμάτων Υποστήριξης (nu-Support Vector Regression). Συγκεκριμένα ένας Προσαρμοζόμενος Γενετικός Αλγόριθμος χρησιμοποιείται για να καθοριστεί το βέλτιστο υποσύνολο χαρακτηριστικών, καθώς και οι βέλτιστες τιμές των παραμέτρων των ταξινομητών. Σαν μέθοδο ταξινόμησης των μεταλλάξεων σε ουδέτερες και παθογενείς, προτείνουμε τον nu-SVR ταξινομητή, καθώς παρουσιάζει υψηλή απόδοση, καλή γενίκευση, δεν παγιδεύεται σε τοπικά βέλτιστα, ενώ ταυτόχρονα επιτυγχάνει την ισορροπία μεταξύ της ακρίβειας και της πολυπλοκότητας του μοντέλου. Μάλιστα για να ξεπεράσουμε τα πρόβληματα των ελλιπών τιμών και της ανισορροπίας των δύο κλάσεων ταξινόμησης, αλλά και για να βελτιώσουμε τη συνολική απόδοση της μεθοδολογίας μας, επεκτείναμε τον υβριδικό αλγόριθμο, ώστε να λειτουργεί σαν μία ensemble-συλλογική τεχνική, συνδυάζοντας οκτώ επί μέρους μοντέλα ταξινόμησης. Τα πειραματικά αποτελέσματα της προτεινόμενης μεθοδολογίας ήταν εξαιρετικά ελπιδοφόρα, καθώς η EnsembleGASVR μεθοδολογία υπερτερεί σημαντικά έναντι άλλων ευρέως γνωστών μεθόδων ταξινόμησης παθογενών μεταλλάξεων. / Single Nucleotide Polymorphisms (SNPs) are the most common form of genetic variations in humans. The number of SNPs that have been found in human genome and affect protein functionality is constantly increasing. Finding matches between SNPs and diseases using experimental techniques, is excessive disadvantageous in terms of time and cost. For this reason, several computational methods have been developed. These methods classify polymorphisms as pathogenic and non-pathogenic. Most of them use classifiers, which take as input a set of structural, functional, sequential and evolutionary features and predict whether a single nucleotide polymorphism is pathogenic or neutral. For training these classifiers use two sets of SNPs. The first one consists of SNPs that have been experimentally proven as pathogenic, whereas the second set consists of SNPs that have been experimentally characterized as benign. These methods differ in the classification methods they deploy and in the features they use as inputs. However, the main problem is the determination of an empirically verified set of features for training. Specifically, different methods suggest different feature sets, without adequately documenting the causes of this differentiation. In addition, the existing methodologies do not tackle efficiently the class imbalance problem between positive and negative training sets and the problem of missing values in the datasets.
In this thesis a new hybrid computational intelligence methodology is proposed, that overcomes many of the problems of existing methodologies. The proposed method achieves high classification performance and systematizes the selection of relevant features. In the first phase of this study the polymorphisms were gathered from the available public databases and they were used for training and testing of the machine learning models. Specifically, the positive and negative training and test sets were collected and filtered. They consist of single nucleotide polymorphisms that lead to either pathogenesis or are neutral. For each polymorphism of the two sets, using existing available tools, a wide range of structural, functional, sequential and evolutionary features were calculated. For those features for which there was no available tool, the suitable program (code) was developed in order to compute them.
In the second step a new embedded hybrid classification method called EnsembleGASVR is designed and implemented. The method uses an ensemble methodology, based on hybrid combination of Genetic Algorithms and nu-Support Vector Regression (nu-SVR) models. An Adaptive Genetic Algorithm is used to determine the optimal subset of features and the optimal values of the parameters of classifiers. We propose the nu-SVR classifier, since it exhibits high performance, good generalization ability, it is not trapped in local optima and achieves a balance between accuracy and complexity of the model. In order to overcome the problem of missing values and class imbalance, we extended the above algorithm to function as a collective ensemble-technique, combining eight individual classification models. In overall, the method achieves 87.45% accuracy, 71.78% sensitivity and 93.16% specificity. These priliminary results are very promising and shows that EnsembleGASVR methodology significantly outperforms other well-known classification methods for pathogenic mutations.
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Genetics of litter size and prenatal survival in pigsHernández Velasco, Silvia Clara January 2012 (has links)
Female reproductive performance is a critical component of sustainable pig production systems. There is abundant evidence of genetic variation in these traits among pig breeds. The aims of this study were to identify quantitative trait loci (QTL) affecting reproductive traits and to identify and characterise positional candidate gene(s) underlying the QTL. A Large White - Meishan F2 population was scanned for QTL with effects on reproductive traits. This analysis revealed 13 putative QTLs on seven different chromosomes with effects on five different traits: ovulation rate (OR), teat number (TN), prenatal survival (PS), total born alive (TBA) and litter size (LS). QTL for PS and LS on chromosome 8 were fine mapped and Secreted Phosphoprotein 1 (SPP1) confirmed as a candidate gene. A genome-wide association study was performed on a diverse population of different breeds and crosses lines, for reproductive traits including LS, TBA, number of stillborn piglets, and number of mummified piglets. Fourteen SNPs were found significantly associated with reproductive traits. The functional study of SPP1 examined the hypothesis that differences in foetal growth may be associated with the effectiveness of conceptus attachment, as measured by SPP1 expression. Patterns of SPP1 mRNA and protein expression in placental and uterine tissues supplying the smallest and a normal-sized foetus from the same uterus were examined in Large White-Landrace (LW-LR), Large White (LW) and Meishan (MS) females 40 and 45 of pregnancy. The smallest LW-LR foetuses tended to have a higher level of SPP1 mRNA in endometrium tissue compared to the normal-sized foetuses. However, placenta expression was higher in the normal-sized foetuses compared to the smallest ones. SPP1 protein levels in normal sized foetuses were significantly higher than in the smallest litter mates for all the tissues. Significantly higher levels of SPP1 mRNA and protein were found in MS compared to LW. In both breeds, significant differences between sizes were found in some tissues, with similar expression patterns in respect to size, for both mRNA and protein in endometrial tissues when compared to contemporary LW. In placenta, the direction of the expression differed between breeds, with a higher expression of mRNA and protein in the normal-sized MS foetuses and in the smallest sized LW foetuses. The comparison of SPP1 expression between different foetal sizes and different breeds revealed associations between breed, foetal size, and SPP1 protein, factors implicated in PS and LS. These results together with the genetic evidence indicate that the potential role of SPP1 in placental and foetal development merits further investigation.
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Transtorno depressivo maior e transtorno bipolar: diferenciação por fatores genéticos, hormonais e exposição a estresse precoce / Major depressive disorder and bipolar disorder: differentiation by genetic and hormonal factors, and exposure to early-life stressMenezes, Itiana Castro 14 March 2019 (has links)
Ainda são escassos estudos que avaliem biomarcadores para diferenciação de transtorno depressivo maior (TDM) e transtorno bipolar (TB), principalmente relativo à etiologia desses transtornos e sua relação com os receptores glicocorticoides (GR) e, principalmente, com os receptores mineralocorticoides (MR). Objetivo: Encontrar biomarcadores genéticos e/ou hormonais e observar sua associação entre si e/ou a fatores externos (estresse precoce - EP) para compreender melhor sua fisiopatogenia e auxiliar no diagnóstico diferencial entre TDM e TB. Material e Métodos: Participaram deste estudo N=273 sujeitos, sendo n=113 controles, n=78 unipolares e n=82 bipolares. A triagem diagnóstica de todos os sujeitos foi realizada por meio do MINI PLUS, checagem de história de trauma na infância pela CTQ, avaliação de sintomas depressivos pela GRID-HAM-D21, e demais comorbidades pela BAI, BHS e BSI. Na busca de biomarcador genético, observou-se as frequências genotípicas e alélicas de 3 polimorfismos de receptor de glicocorticoide (GR) (N363S, R22/23K e BclI) e de 2 polimorfismos de MR (MI180V e -2G/C) após realizada a discriminação alélica por reação em cadeia da polimerase quantitativa (qPCR). Foram avaliados de forma intragrupo as variáveis genéticas e endócrinas (e combinadas) e o efeito do EP sobre tais variáveis. Também, as variáveis polimorfismos, níveis hormonais e exposição a EP foram comparadas entre grupos para avaliar se havia diferença de prevalência, de perfil endócrino, ou se havia suscetibilidade maior por parte dos unipolares ou bipolares para alteração dos níveis hormonais e/ou intensidade do quadro depressivo frente a EP ou a determinado genótipo. Resultados: Todos os sujeitos unipolares e bipolares mostraram piora de seus sintomas depressivos frente a EP e seus subtipos, sendo eles unipolares ou bipolares. Como biomarcador hormonal, comparando-se controles x unipolares x bipolares, ou apenas unipolares x\' bipolares, foi possível observar que os níveis de cortisol e os níveis de aldosterona apresentaram-se os altos em unipolares e os baixos mais em bipolares, quando estes pacientes estavam com depressão grave ou gravíssima. Também, bipolares expostos a EP global, abuso físico e emocional mostraram níveis mais baixos de aldosterona que bipolares que não foram expostos. Frente a exposição a esses EP global e abuso físico, os bipolares tenderam a se mostrar mais suscetíveis que os unipolares a alteração dos níveis de aldosterona. Para biomarcador genético, frequência de genótipos ou alelos não diferenciaram unipolares de bipolares. Entretanto, houve maior prevalência do genótipo heterozigoto AG de GR N363S em pacientes depressivos uni e bipolares quando comparados com controles. Combinando-se os biomarcadores genéticos e hormonais, unipolares apresentaram níveis mais baixos de cortisol e de aldosterona quando carregavam genótipo variante GG de MR -2G/C, enquanto bipolares mostraram tendência a redução de cortisol quando carregavam o alelo variante G de MR MI180V. Quando comparados os genótipos por si só, intragrupo, novamente o polimorfismo MR -2G/C mostra influência sobre o fenótipo unipolar. Em unipolares, presença do alelo variante G de MR -2G/C piora significativamente o quadro depressivo, mas o alelo variante G de MI180V mostrou-se protetor frente a EP. Tanto os unipolares frente aos outros 4 polimorfismos, quanto os bipolares frente a todos os polimorfismos estudados, apresentaram piora significativa de seu quadro depressivo se expostos a EP. Bipolares mostraram uma tendência a ser mais suscetíveis que unipolares a alterações endócrinas (aldosterona) quando expostos a EP global e abuso físico. Conclusão: Tendo em vista os vários achados significativos a cerca dos polimorfismos de MR, tanto para unipolar quanto para bipolar, sua influência sobre os níveis de aldosterona e cortisol basais, reforça-se a importância do papel dos receptores MR dentro da etiologia dos transtornos depressivos unipolares e bipolares, e a forma diferente de funcionamento do MR para a distinção entre TDM e TB / There are still few studies assessing biomarkers for differentiation of major depressive disorder (MDD) and bipolar disorder (TB), mainly related to the etiology of these disorders and its relationship with glucocorticoid receptors (GR) and, manily, with mineralocorticoid receptors (MR). Aim: Finding genetic and / or hormonal biomarkers and observing their association to each other and / or external factors (early-life stress - ELS) for better comprehend their pathophysiology and, then, assisting in differential diagnosis between MDD and TB. Material and Methods: A total of N = 273 subjects composed the study sample, being n = 113 control, n = 78 unipolar, and n = 82 bipolar subjects. The diagnostic screening of all subjects was performed applying MINI PLUS, for history of ELS, CTQ; assessment of depressive symptoms, GRID-HAM-D21; and assessment of other comorbidities, BAI, BHS, and BSI. Researching for genetic biomarker, genotypic and allelic frequencies of 3 GR polymorphisms (N363S, R22 / 23K and BclI) and 2 MR polymorphisms (MI180V and -2G/C) were evaluated after allelic discrimination by quantitative polymerase chain reaction (qPCR). Genetic and endocrine variables (and their combination), and the effect of ELS over these variables were assessed intragrups. Also, polymorphisms, hormonal levels and history to ELS were compared between groups to assess whether there was difference in prevalence, endocrine profile, or whether there was greater susceptibility on the part of unipolar or bipolar for alteration of hormonal levels and / or severity of depressive symptoms considering history of ELS and/or a specific genotype. Results: All unipolar and bipolar subjects showed worsening of their depressive symptoms in the presence of ELS and its subtypes. As hormonal biomarker, comparing unipolar x bipolar x control subjects, or comparing unipolar x bipolar, cortisol and aldosterone levels were higher in unipolar subjects, and lower in bipolar subjects, when these patients presented severe or very severe depressive symptoms. Also, bipolar subjects\' exposed to global ELS, physical and emotional abuse showed lower basal levels of aldosterone than did bipolar who were not exposed to ELS. Concerning global ELS and physical abuse, bipolar tended to be more susceptible than unipolar for aldosterone levels to change. For genetic biomarker, frequency of genotypes or alleles did not distinguished unipolar from bipolar sample. However, there was a higher prevalence of GR N363S heterozygous genotype (AG) in unipolar and bipolar depressive patients when compared to controls. Combining the genetic and hormonal biomarkers, unipolar had lower levels of cortisol and aldosterone when carrying GG variant genotype of MR-2G / C, while bipolar showed tendency to reduce cortisol when carrying the variant G allele of MR MI180V. When comparing the genotypes (intragroup), again, MR-2G/C polymorphism shows influence on the unipolar phenotype. In unipolar, the presence of the variant G allele of MR-2G / C significantly worsens the depressive condition, unlike variant G allele of MI180V has shown to be protective against ELS. Both the unipolar compared to the other 4 polymorphisms, and the bipolar ones against all polymorphisms studied, presented a significant worsening of their depressive condition if exposed to ELS. Bipolar tend to be more susceptible than unipolar to endocrine changes (aldosterone) when exposed to global ELS and physical abuse. Conclusion: Considering the several significant findings regarding MR polymorphisms, for both unipolar and bipolar subjects, and their influence on basal aldosterone and cortisol levels, we highlight importance of the role of MR receptors within the etiology of depressive unipolar and bipolar disorders, and different way of MR functioning in each disorder for assisting the distinction between MDD and TB
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Développement de représentations et d'algorithmes efficaces pour l'apprentissage statistique sur des données génomiques / Learning from genomic data : efficient representations and algorithms.Le Morvan, Marine 03 July 2018 (has links)
Depuis le premier séquençage du génome humain au début des années 2000, de grandes initiatives se sont lancé le défi de construire la carte des variabilités génétiques inter-individuelles, ou bien encore celle des altérations de l'ADN tumoral. Ces projets ont posé les fondations nécessaires à l'émergence de la médecine de précision, dont le but est d'intégrer aux dossiers médicaux conventionnels les spécificités génétiques d'un individu, afin de mieux adapter les traitements et les stratégies de prévention. La traduction des variations et des altérations de l'ADN en prédictions phénotypiques constitue toutefois un problème difficile. Les séquenceurs ou puces à ADN mesurent plus de variables qu'il n'y a d'échantillons, posant ainsi des problèmes statistiques. Les données brutes sont aussi sujettes aux biais techniques et au bruit inhérent à ces technologies. Enfin, les vastes réseaux d'interactions à l'échelle des protéines obscurcissent l'impact des variations génétiques sur le comportement de la cellule, et incitent au développement de modèles prédictifs capables de capturer un certain degré de complexité.Cette thèse présente de nouvelles contributions méthodologiques pour répondre à ces défis.Tout d'abord, nous définissons une nouvelle représentation des profils de mutations tumorales, qui exploite leur position dans les réseaux d'interaction protéine-protéine. Pour certains cancers, cette représentation permet d'améliorer les prédictions de survie à partir des données de mutations, et de stratifier les cohortes de patients en sous-groupes informatifs. Nous présentons ensuite une nouvelle méthode d'apprentissage permettant de gérer conjointement la normalisation des données et l'estimation d'un modèle linéaire. Nos expériences montrent que cette méthode améliore les performances prédictives par rapport à une gestion séquentielle de la normalisation puis de l'estimation. Pour finir, nous accélérons l'estimation de modèles linéaires parcimonieux, prenant en compte des interactions deux à deux, grâce à un nouvel algorithme. L'accélération obtenue rend cette estimation possible et efficace sur des jeux de données comportant plusieurs centaines de milliers de variables originales, permettant ainsi d'étendre la portée de ces modèles aux données des études d'associations pangénomiques. / Since the first sequencing of the human genome in the early 2000s, large endeavours have set out to map the genetic variability among individuals, or DNA alterations in cancer cells. They have laid foundations for the emergence of precision medicine, which aims at integrating the genetic specificities of an individual with its conventional medical record to adapt treatment, or prevention strategies.Translating DNA variations and alterations into phenotypic predictions is however a difficult problem. DNA sequencers and microarrays measure more variables than there are samples, which poses statistical issues. The data is also subject to technical biases and noise inherent in these technologies. Finally, the vast and intricate networks of interactions among proteins obscure the impact of DNA variations on the cell behaviour, prompting the need for predictive models that are able to capture a certain degree of complexity. This thesis presents novel methodological contributions to address these challenges. First, we define a novel representation for tumour mutation profiles that exploits prior knowledge on protein-protein interaction networks. For certain cancers, this representation allows improving survival predictions from mutation data as well as stratifying patients into meaningful subgroups. Second, we present a new learning framework to jointly handle data normalisation with the estimation of a linear model. Our experiments show that it improves prediction performances compared to handling these tasks sequentially. Finally, we propose a new algorithm to scale up sparse linear models estimation with two-way interactions. The obtained speed-up makes this estimation possible and efficient for datasets with hundreds of thousands of main effects, thereby extending the scope of such models to the data from genome-wide association studies.
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Genetic analysis of mitochondrial DNA within Southern African populations.Brecht, Gadean January 2020 (has links)
>Magister Scientiae - MSc / As human beings we are curious about our origin and ancestry. A curiosity has led to an investigation of human evolution and expansion across the world by means of population genetics and phylo-genetics by evaluating a region in Southern Africa that is largely unknown.
The objective of this study was to develop a quick, inexpensive and accurate hierarchical diagnostic screening system of the MtDNA phylogenetic tree, AI-SNPs in the mtDNA genome by using High Resolution Melting analysis to evaluate the population composition and ancestral haplogroups of Southern African populations in Limpopo. The admixture between the ‘Khoesan’ hunter-gatherers, herders and the Bantu speaking populations led to population growth and expansion in Limpopo. This has contributed to populations settling in Limpopo and has thus shaped the ancestral contemporary populations. No research on these individuals residing in Limpopo has been done before, thus an investigation of their ancestral origin was necessary. A total of 760 saliva samples were collected from individuals residing in Limpopo. Only 500 saliva samples were extracted by means of an optimized salting out technique. Five hundred extracted genomic samples were genotyped by means of a quick, inexpensive High-resolution melting analysis. Of the 500 samples, the genotyping results showed 95 individuals derived for the L3 haplogroup which gives a 19% ratio of individuals screened with Multiplex 1. Only 56 individuals were derived for the L1 haplogroup, which gives a percentage of 11%. A total of 249 individuals were derived for the L0 haplogroup, making up a 50% of the total individuals genotyped. Only 100 samples were derived for L0a, making up 20% of individuals screened with Multiplex 1. Of the 95 samples derived for the L3 haplogroup, the results showed 87 individuals to be ancestral for both M and N, making up 91.57% of individuals screened with Multiplex 2. http://etd.uwc.ac.za/. In population genetics using SNPs to infer population history and ancestral origin has become significant, this study allowed researchers to evaluate population groups by investigating their genetic markers and the application of the results allowed for downstream analyses. Finally, this study provides a quick and simple screening method for the selection of lineages that are of interest for further studies.
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