Submitted by Chaylane Marques (chaylane.marques@ufpe.br) on 2015-03-12T19:50:41Z No. of bitstreams: 2 JoaoPacificoBezerraNeto_Dissertação_Mestrado_PPGG2012.pdf: 5337016 bytes, checksum: dd95563c1fc978c7a83bb7ff2526ef28 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-12T19:50:41Z (GMT). No. of bitstreams: 2 JoaoPacificoBezerraNeto_Dissertação_Mestrado_PPGG2012.pdf: 5337016 bytes, checksum: dd95563c1fc978c7a83bb7ff2526ef28 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012 / CAPES; CNPQ; FACEPE; BNB; FINEP / O feijão-caupi é uma das mais antigas leguminosas cultivadas, com destacada importância em áreas tropicais e subtropicais. No Brasil, é uma das principais fontes de nutrientes para a dieta humana e animal, representando 80% da produção de grãos nas regiões norte e nordeste. Entretanto, fatores como seca e salinidade (as duas principais adversidades ambientais em regiões semiáridas) têm prejudicado tanto a quantidade quanto a qualidade da produção do feijão-caupi. Neste sentido, o estudo de proteínas que agem como facilitadoras da passagem de água entre as membranas biológicas e na prevenção da passagem de íons e outros solutos na célula é fundamental para o entendimento de como algumas plantas respondem a tais adversidades. Entre estas proteínas as aquaporinas merecem atenção, tratandose de uma família de pequenas proteínas transmembranas (24-30 kDa), dividida em quatro subfamílias, incluindo as Proteínas de Membrana Plasmática (PIP), Proteínas de Membrana de Tonoplasto (TIP), Proteínas de Membrana de Nódulos (NIP) e Pequenas Proteínas Básicas Intrínsecas de Membrana (SIP). Apesar da grande quantidade de dados sobre aquaporinas nos vegetais, nada se sabe sobre estes transportadores em algumas culturas de importância econômica, como o feijãocaupi. Utilizando dados de EST (Expressed Sequence Tags), 37 transcritos candidatos a aquaporinas foram identificados em feijão-caupi por meio de buscas com ferramentas de bioinformática, onde 27 apresentavam o domínio íntegro e 10 encontravam-se incompletas. Análises fenéticas das sequências de aminoácidos dividiram esta família nas quatro subfamílias já conhecidas para outras espécies vegetais, sendo 11 PIPs (cinco PIP1 e seis PIP2), 10 TIPs (quatro TIP3 e seis TIP), quatro NIPs e duas SIPs. Os alinhamentos múltiplos gerados a partir das sequências com domínio MIP completo, indicaram que as regiões ar/R das aquaporinas do feijão-caupi, em sua maioria, são similares às presentes em Arabidopsis, milho e arroz, apontando para afinidades com o mesmo tipo de soluto transportado. A expressão dos transcritos foi observada em todos os tecidos vegetais, estando associadas ao transporte de diferentes tipos de solutos nos compartimentos celulares. As aquaporinas identificadas neste estudo representam um importante recurso genético, fornecendo alvos em potencial para modificar as propriedades do uso de água em feijão-caupi ou em outras leguminosas relacionadas.

La première partie de la thèse traite de la recherche de biomarqueurs du cancer. Lors de la transcription, il apparaît que certains nucléotides peuvent être remplacés par un autre nucléotide. On s'intéresse alors à la comparaison des probabilités de survenue de ces infidélités de transcription dans des ARNm cancéreux et dans des ARNm sains. Pour cela, une procédure de tests multiples menée sur les positions des séquences de référence de 17 gènes est réalisée via les EST (Expressed Sequence Tag). On constate alors que ces erreurs de transcription sont majoritairement plus fréquentes dans les tissus cancéreux que dans les tissus sains. Ce phénomène conduirait ainsi à la production de protéines dites aberrantes, dont la mesure permettrait par la suite de détecter les patients atteints de formes précoces de cancer. La deuxième partie de la thèse s'attache à l'étude de l'allergie à l'arachide. Afin de diagnostiquer l'allergie à l'arachide et de mesurer la sévérité des symptômes, un TPO (Test de Provocation Orale) est réalisé en clinique. Le protocole consiste à faire ingérer des doses croissantes d'arachide au patient jusqu'à l'apparition de symptômes objectifs. Le TPO pouvant se révéler dangereux pour le patient, des analyses discriminantes de l'allergie à l'arachide, du score du TPO, du score du premier accident et de la dose réactogène sont menées à partir d'un échantillon de 243 patients, recrutés dans deux centres différents, et sur lesquels sont mesurés 6 dosages immunologiques et 30 tests cutanés. Les facteurs issus d'une Analyse Factorielle Multiple sont également utilisés comme prédicteurs. De plus, un algorithme regroupant simultanément en classes des intervalles comprenant les doses réactogènes et sélectionnant des variables explicatives est proposé, afin de mettre ensuite en compétition des règles de classement. La principale conclusion de cette étude est que les mesures de certains anticorps peuvent apporter de l'information sur l'allergie à l'arachide et sa sévérité, en particulier ceux dirigés contre rAra-h1, rAra-h2 et rAra-h3. / The first part of this doctoral dissertation deals with the research of cancer biomarkers. During transcription it was observed that some nucleotides are replaced mistakenly by others. We sought to compare the probabilities of these transcription infidelities in mRNA originating from normal and cancerous tissues. To do this, a multiple testing procedure was performed on the positions of 17 genes by considering their ESTs (Expressed Sequence Tag). The conclusion was reached that the proportions of these transcription errors are mainly increased in cancer tissues as compared to normal ones. This phenomenon would lead to the translation of aberrant proteins, whose detection could help in identifying patients with cancer. The main goals of the second part are the diagnosis of peanut allergy and the prediction of its severity. Diagnosing peanut allergy and evaluating the intensity of the symptoms are currently accomplished with a double blind placebo controlled food challenge (DBPCFC). Patients are given increasing peanut doses until the first clinical reaction appears. Since DBPCFC can result in life-threatening responses, we propose an alternate procedure with the long term goal of replacing invasive allergy tests. Discriminant analyses of peanut allergy, DBPCFC score, the eliciting dose and the first accidental exposure score were performed in 243 allergic patients using 6 immunoassays and 30 skin prick tests. A Multiple Factorial Analysis was performed to use new factors as predictors. We also developed an algorithm for simultaneously clustering eliciting dose values and selecting discriminant variables. Our main conclusion is that antibody measurements provide information on the allergy and its severity, especially those directed against the peanut allergens rAra-h1, rAra-h2 and rAra-h3.

Submitted by Alisson Mota (alisson.davidbeckam@gmail.com) on 2015-07-13T19:18:49Z No. of bitstreams: 1 Tese - Marcicleide Lima do Espirito Santo.pdf: 7339955 bytes, checksum: 22519cc9c5e5f14e2991f1e20ddb938f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-15T18:14:34Z (GMT) No. of bitstreams: 1 Tese - Marcicleide Lima do Espirito Santo.pdf: 7339955 bytes, checksum: 22519cc9c5e5f14e2991f1e20ddb938f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-15T18:19:56Z (GMT) No. of bitstreams: 1 Tese - Marcicleide Lima do Espirito Santo.pdf: 7339955 bytes, checksum: 22519cc9c5e5f14e2991f1e20ddb938f (MD5) / Made available in DSpace on 2015-07-15T18:19:56Z (GMT). No. of bitstreams: 1 Tese - Marcicleide Lima do Espirito Santo.pdf: 7339955 bytes, checksum: 22519cc9c5e5f14e2991f1e20ddb938f (MD5) Previous issue date: 2006-06-22 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / The camu-camu (Myrciaria dubia (H.B.K.) McVaugh) is a native sort of the Amazonian region, whose fruit presents elevated content of ascorbic acid (vitamin C). The study of the functional genome in camu-camu fruits has like base the expressed sequence tags sequencing - ESTs. Faced with the displayed the present thesis is going to analyze and identify express genes in camu-camu fruits by means of ESTs sequencing. The total RNA was extracted from the shell-pulp. The extremity 5’sequencing' of cDNA insert was carried out so much in the Technology of the DNA Laboratory (UFAM) and in the Sequencing Platform (EMBRAPA/CENARGEN). The ESTs sequences obtained were submitted to the System Genome, program of genomic annotation that integrates analysis management programs and viewing of nucleotides sequences. It developed an efficient procedure for total RNA extraction of camu-camu fruits that enabled the obtaining of mRNAs of quality, utilized in the making of cDNAs of sizes varied (500pb to 4Kb). From the sequencing were obtained 3196 ESTs valid, being formed 1546 singletons and 358 contigs, resulting of 2586 ESTs sequences in total with similarity the sequences found in the gene bank. The analysis library clusterization revealed an index of 81% novelty and 32,54% redundancy. Around 90% of the contigs presented decrease redundancy (2-4 reads by contigs). The facts of the categorization of the proteins identified detached the posttranslational modification, protein turnover, chaperones (13,2%) category. From the hoist of the species with bigger number of ESTs with similarity the camu-camu sequences detached itself Arabidopsis thaliana with 49%. Around 10 uniques presented very high similarity (and-value 0.0) to known genes. The ESTs more abundantly express in camu-camu fruits encode to gluthatione s-transferase. They were observed around 3% sequences (97 ESTs) with decrease similarity (e-value > e-10) and 15% did not they present similarity with no contained sequence in the gene bank. They were identified 138 ESTs sequences (4,3%) that they encode molecular chaperones with prevalence of the sHSP family that represents 33% of express chaperones. ESTs related to the ascorbic acid metabolism also were identified, being nine related the synthesis and six come back for ascorbic acid conversion and recycling. ESTs related to the ripening and mechanisms of defense of the fruit also were noticeable. / O camu-camu (Myrciaria dúbia (H.B.K.) McVaugh) é uma espécie nativa da região Amazônica, cujo fruto apresenta elevado teor de ácido ascórbico (vitamina C). O estudo do genoma funcional em frutos de camu-camu tem como base o seqüenciamento de fragmentos de seqüências expressas - ESTs (Expressed Sequence Tags). Diante do exposto a presente tese pretende analisar e identificar genes expressos em frutos de camu-camu por meio de seqüenciamento de ESTs. O RNA total foi extraído a partir da casca-polpa. O seqüenciamento da extremidade 5’ de insertos de cDNA foi realizado tanto no Laboratório de Tecnologia do DNA da UFAM e como na Plataforma de Seqüenciamento da EMBRAPA/CENARGEN. As seqüências ESTs obtidas foram submetidas ao Sistema Genoma, programa de anotação genômica que integra programas de gerenciamento de análise e visualização de seqüências nucleotídicas. Os resultados obtidos foram o desenvolvimento de um procedimento eficiente para extração de RNA total de frutos de camu-camu que possibilitou a obtenção de mRNAs de qualidade, utilizados na confecção de cDNAs de tamanhos variados (500pb a 4Kb). A partir do seqüenciamento foram obtidas 3196 ESTs válidas, sendo formados 1546 singletons e 358 contigs, resultando num total de 2586 seqüências ESTs com similaridade a seqüências encontradas no banco de genes. A análise da clusterização da biblioteca revelou um índice de 81% de novidade e 33% de redundância. Cerca de 90% dos contigs apresentaram baixa redundância (2-4 reads por contigs). Os dados da categorização das proteínas identificadas destacaram a categoria modificação pós-traducional, proteína turnover, chaperonas (13,2%). A partir do levantamento das espécies com maior número de ESTs com similaridade a seqüências de camu-camu destacou-se Arabidopsis thaliana com 49%. Cerca de 10 uniques apresentaram altíssima similaridade (e-value 0.0) a genes conhecidos. Os ESTs mais abundantemente expresso em frutos de camu-camu codificam a glutationa s-transferase. Foram observados cerca de 3% de seqüências (97 ESTs) com baixa similaridade (e-value > e-1010) e 15% não apresentaram similaridade com nenhuma seqüência contida no banco de genes. Foram identificadas 138 seqüências ESTs (4,3%) que codificam chaperonas moleculares com destaque à família sHSP que representa 33% das chaperonas expressas. ESTs relacionados ao metabolismo do ácido ascórbico também foram identificados, sendo nove relacionados a síntese e seis voltados para conversão e reciclagem do ácido ascórbico. ESTs relacionados ao amadurecimento e mecanismos de defesa do fruto também foram destacados.

Expressed sequence tags (ESTs) are derived from the developing tilapia brain was established in our lab. There are 9 transcripts were identified as thermosensitive/Neural development-related gene. The effects of different temperatures on the ontogenetic expression of these thermosensitive/Neural development-related gene during the critical period of brain sexual differentiation were investigated in the present study. The ontogenetic expression of inhibitor of DNA binding/differentiation protein 2 (Id2), thermosensitive/Neural development-related gene, were enhanced by both lower (20¢J) and higher (32¢J) temperatures before 10 days post-hatching. In this study, bioinformatics were searched for Id2, which is a gene with 738 bp of patial cDNA sequence, open reading frame (ORF) is 411bp, and deduced 137 amino acids of protein sequence. The protein of Id2 was expressed in a prokaryotic system, BL21 (Escherichia coli) and purified with Ni-NTA affinity chromatography. Also, the ORF of Id2 was cloned into pEGFP vector, and plasmid (pEGFP-Id2) was transfected into the eukaryotic system, mouse neuroblastoma cell (Neuro-2a cell). The distribution of Id2 expressed in the Neuro-2a cell was identified by fluorescence microscopy.

Thesis (MSc (Genetics))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The South African abalone, Haliotis midae, is the only endemic species of commercial value. Aquaculture remains the only avenue for expanding the industry, since the closure of the fishery. The current focus is on implementing a molecular breeding programme; thus the development of molecular markers for linkage mapping and QTL analysis is a priority. Various markers, mainly anonymous, have been developed for H. midae; however emphasis is being placed on the development of gene-linked type I molecular markers. The present study investigates and demonstrates the use of public sequence collections to develop type I markers for a species with limited genomic resources, via three strategies: Surveying anonymous H. midae microsatellite markers’ flanking regions to find homology to gene sequences in public databases, cross-species marker transfer of anonymous markers from H. rubra and H. discus hannai demonstrating putative gene associations and lastly EST marker mining (SNP and microsatellites) from various Haliotids and testing transfer to the target species. Approximately 17% of H. midae anonymous markers showed significant similarity to genes. The current study also reports higher cross-species transferability from both H. rubra and H. discus hannai to H. midae (39% and 20.5%, respectively) than previously demonstrated and 15 EST-microsatellites and 16 EST-SNPs were successfully mined. Furthermore, the non-random distribution of microsatellites and high nucleotide diversity in the H. midae genome was confirmed. This is a low cost and time effective method for marker development and presents a continuous and dynamic resource that could be used for future marker development and characterisation as sequence information in public databases grow exponentially. / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse perlemoen, Haliotis midae, is die enigste van vyf inheemse spesies van kommersiële waarde. Na die noodgedwonge sluiting van die vissery, is akwakultuur die mees praktiese oplossing om die perlemoen industrie uit te brei. Die huidige fokus is gerig op die implementering van ‘n molekulêre teel-program en dus is die ontwikkeling van molekulêre merkers vir genetiese kartering en kwantitatiewe kenmerk lokus analise, van uiterste belang. Tipe II merkers is voorheen vir die perlemoen ontwikkel, maar huidige tendense lê klem op die ontwikkeling van geen-gekoppelde tipe I merkers. Die huidige studie ondersoek die gebruik van publieke databasisse vir die ontwikkeling van tipe I molekulêre merkers vir ‘n spesie met beperkte genomiese bronne. Drie strategieë is geïmplementeer: Eerstens is ‘n opname gemaak van die homologie van perlemoen tipe II merker-vleuelende volgordes met geen volgordes in databasisse. Verder is die oordraagbaarheid van tipe II merkers vanaf H. rubra en H. discus hannai wat assosiasie met gene toon ondersoek. Laastens is ‘n Uitgedrukte Volgorde Merk (UVM) (Expressed Sequence Tag, EST) merker-ontginnings metode vanaf verskeie Haliotis spesies en toetsing van oordraagbaarheid na die teiken spesie uitgevoer. Ongeveer 17% van die tipe II H. midae merkers het geniese assosiasie getoon. ‘n Hoër tussen-spesie oordraagbaarheid vanaf beide H. rubra en H. discus hannai na H. midae (39% en 20.5%, onderskeidelik) word gerapporteer in vergelyking met vorige studies en 15 UVM-mikrosatelliete en 16 UVM-enkel nukleotied polimorfismes (single nucleotide polimorphism, SNP) is ontwikkel. Verder bevestig die studie die nie-lukrake verspreiding van mikrosatelliete en hoë nukleotied diversiteit in die perlemoen genoom. Die gebruik van publieke databasise vir die ontwikkeling en karakterisering van tipe I molekulêre merkers is tyd- en koste-besparend en bied ‘n volgehoue en dinamiese bron vir toekomstige gebruik.

Resumo: Sob condições de estresse hídrico, a cana-de-açúcar pode sofrer mudanças fisiológicas e bioquímicas, tais como diminuição nas atividades fotoquímicas, redução da fixação de CO2 e acúmulo de osmólitos e osmoprotetores. O objetivo deste trabalho foi identificar, através da técnica de macroarranjo de cDNA, o perfil de expressão de genes promotores das diferentes vias metabólicas em palmitos da variedade de cana-de-açúcar SP80-3280 submetidas ao estresse hídrico nos dias 5, 9, 13 e 17 após o início da condição de supressão de água, sendo considerado o dia 1 como controle. Os resultados do macroarranjo mostraram que as proteínas mais expressas sob déficit hídrico pertencem a quatro categorias das quais as ESTs mais importantes foram selecionadas. As quatro categorias descritas abaixo estão discutidas neste trabalho. As ESTs da via do metabolismo de açúcar e amido (invertase de parede celular (INV), sacarose fosfato sintase (SFS), sacarose fosfato fosfatase (SFF), trealose fosfato sintase (TFS), trealose fosfato sintase/fosfatase (TFS/F) e hexoquinase (HXQ)) pertencem a categoria de bioenergética. Colina monooxigenase (CMO) e betaína aldeído desidrogenase (BADH) as quais pertencem a via do metabolismo de glicina betaína, foram selecionadas a partir da categoria do metabolismo secundário. A terceira categoria compreende as ESTs do metabolismo de aminoácido (D-pirrolina-5- carboxilato sintase (P5CS), ornithina -aminotransferase (OAT) e prolil 4-hidroxilase (PH)) as quais pertencem a via da biossíntese de prolina, e a quarta categoria, resposta ao estresse, compreende as ESTs aleno oxido sintase (AOS), aleno oxido ciclase (AOC) e lipoxigenase (LOX), pertencentes a via de biossíntese do jasmonato. / Abstract: Under water deficit, sugarcane undergoes physiological and biochemical alterations such as photochemical activity reduction, CO2 fixation reduction and the accumulation of osmolytes and osmoprotectants. This work was undertaken to identify the gene expression profile in sugarcane (var. SP80-3280) under water deficit through the cDNA macroarray technique. Leafroll tissues were collected from plants subjected to 5, 9, 13 and 17 days of water restriction, and day 1 was used as control. Macroarray results showed that most proteins expressed under water restriction belong to four categories, from which the most important ESTs were selected. The four categories described below are discussed in this work. Sugar and starch metabolism pathway ESTs (cell wall invertase (CWI), sucrose phosphate synthase (SPS), sucrose phosphate phosphatase (SPP), trehalose phosphate synthase (TPS), trehalose phosphate synthase phosphatase (TSP/P) and hexoquinase (HXQ) were selected from the bioenergetics category. Choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH), which belong to the glycine betaine metabolism pathway, were selected from the secondary metabolism category. The third category comprised the amino acid metabolism ESTs D- pyrroline-5-carboxylate synthase (P5CS), Ornithine - aminotransferase (OAT) and Prolyl 4-hydroxylase (PH), which belong to the proline biosynthesis pathway, and the fourth category, stress response, comprised the ESTs for Allene oxide synthase (AOS), Allene oxide cyclase (AOC) and Lipoxygenase (LOX), which belong to the jasmonate biosynthesis pathway. / Orientador: Maria Inês Tiraboschi Ferro / Coorientador: Sonia Marli Zingaretti / Coorientador: Roberto Willians Noda / Banca: João Suzuki / Banca: Poliana Fernanda Giachetto / Mestre

Doctor of Philosophy / Department of Entomology / C. M. Smith / Brenda Oppert / Coleopteran insects compensate for dietary protease inhibitors by a number of mechanisms. To study this compensation response at the molecular level, the digestive proteases of Tenebrio molitor were studied. Biochemical studies of the pH optima and inhibitor sensitivity of proteases indicated the cysteine proteases were mostly in the anterior and serine proteases were in the posterior midgut of T. molitor larvae. Expressed Sequence Tags (ESTs) from T. molitor larval midgut cDNA libraries contained sequences encoding putative digestive proteases. Of a total of 1,528 cDNA sequences, 92 cDNAs encoded proteases, and 50 full-length cDNAs were grouped into serine, cysteine and metallo protease classes. Sequences tmt1a, tmt1b and tmt1c were identified as genes encoding isoforms of T. molitor trypsin, and tmc1a encoded T. molitor chymotrypsin. The general distribution cysteine protease transcripts in the anterior and serine protease transcripts in the posterior midgut, of T. molitor larvae, was in agreement with the biochemically-characterized compartmentalization of proteases. Expression analyses of selected transcripts demonstrated varied expression patterns across five developmental stages of T. molitor, with maximal expression of most protease transcripts in first instar larvae. Dietary serine and cysteine protease inhibitors fed in combination to early-instar T. molitor larvae caused a significant delay in larval growth in 21-day-old larvae. Real-time quantitative PCR analysis of RNA isolated from larvae fed different protease inhibitor treatments indicated that dietary inhibitors affected the expression of serine and cysteine proteases. Larvae fed soybean trypsin inhibitor, a serine protease inhibitor, compensated by the hyperproduction of proteases from the same class, as well as the upregulation of cysteine proteases. A cysteine protease inhibitor, E-64, caused a reduction in the hyperproduction of all proteases, and, in combination with the soybean trypsin inhibitor, lowered the compensation response of T. molitor larvae to negligible levels. These data suggest that T. molitor larvae are more sensitive to the effects of cysteine protease inhibitors, perhaps because these proteases are the first line of defense for larvae against plant protease inhibitor. The bioassay and molecular studies suggested that combinations of inhibitors that target both serine and cysteine proteases are needed to effectively control larval infestations of T. molitor.

Safeners are the chemicals used to protect plants from detrimental effects of herbicides, but their mode of action at the molecular level is not well understood. As an initial step towards understanding the molecular mechanism of safener action in trees, homologous genes in hybrid poplar (Populus nigra x Populus maximowiczii) that were induced by a safener were identified. We here describe the identification of differentially expressed genes in Populus that are induced by Concep-III, a herbicide safener. Expressed sequence tags (ESTs) enriched for transcriptionally induced genes were isolated by suppressive subtractive hybridization (SSH). The SSH library cDNA inserts were used to construct a cDNA microarray for high-throughput validation of the up-regulated expression of safener-induced genes. Single-pass and partial sequences of 1,344 safener-induced ESTs were assembled into 418 single-tons and 328 clusters, but the putative functions of almost 53% of the ESTs are not known. Genes encoding proteins involved in all three different phases of safener action, viz., oxidation, conjugation, and sequestration, were found in the SSH library. Almost 75% of genes that showed greater than 2-fold expression upon safener treatment were redundant in the SSH library. The expression pattern for selected genes was validated by reverse transcription-polymerase chain reaction. A few safener-induced genes that were not previously reported to be induced by safeners, but which may have a role in herbicide metabolism, were identified. The newly identified genes could have potential for application in genetic engineering of plants for herbicide detoxification and tolerance.

This thesis provides an in-depth analyze of expressed sequence tags (EST) that represent pieces of eukaryotic mRNA by using unsupervised hidden Markov model (HMM). ESTs are short nucleotide sequences that are used primarily for rapid identificationof new genes with potential coding regions (CDS). ESTs are made by sequencing on double-stranded cDNA and the synthesizedESTs are stored in digital form, usually in FASTA format. Since sequencing is often randomized and that parts of mRNA contain non-coding regions, some ESTs will not represent CDS.It is desired to remove these unwanted ESTs if the purpose is to identifygenes associated with CDS. Application of stochastic HMM allow identification of region contents in a EST. Softwares like ESTScanuse HMM in which a training of the HMM is done by supervised learning with annotated data. However, because there are not always annotated data at hand this thesis focus on the ability to train an HMM with unsupervised learning on data containing ESTs, both with and without CDS. But the data used for training is not annotated, i.e. the regions that an EST consists of are unknown. In this thesis a new HMM is introduced where the parameters of the HMM are in focus so that they are reasonablyconsistent with biologically important regionsof an mRNA such as the Kozak sequence, poly(A)-signals and poly(A)-tails to guide the training and decoding correctly with ESTs to proper statesin the HMM. Transition probabilities in the HMMhas been adapted so that it represents the mean length and distribution of the different regions in mRNA. Testing of the HMM's specificity and sensitivityhave been performed via BLAST by blasting each EST and compare the BLAST results with the HMM prediction results.A regression analysis test shows that the length of ESTs used when training the HMM is significantly important, the longer the better. The final resultsshows that it is possible to train an HMM with unsupervised machine learning but to be comparable to supervised machine learning as ESTScan, further expansion of the HMM is necessary such as frame-shift correction of ESTs byimproving the HMM's ability to choose correctly positioned start codons or nucleotides. Usually the false positive results are because of incorrectly positioned start codons leadingto too short CDS lengths. Since no frame-shift correction is implemented, short predicted CDS lengths are not acceptable and is hence not counted as coding regionsduring prediction. However, when there is a lack of supervised models then unsupervised HMM is a potential replacement with stable performance and able to be adapted forany eukaryotic organism.

Les éléments transposables sont des composants majeurs de la plupart des génomes, et leur impact sur l’évolution des génomes est maintenant bien documenté. Cependant, la manière par laquelle ils participent au transcriptome n’est pas encore clairement établie. En utilisant le génome séquencé de Drosophila melanogaster et les bibliothèques d’EST, nous avons déterminé les insertions d’éléments transposables qui sont transcrites sans équivoque, ainsi que leur localisation dans le génome séquencé de D.melanogaster. Nous montrons que la plupart des familles d’éléments transposables sont transcrites, et nous identifions spécifiquement 69 insertions d’éléments transposables exprimés, dont la moitié réside dans des gènes, la plupart dans des introns et des régions régulatrices 5’UTR. / Transposable elements (TEs) are major components of most genomes, and their impact on genome evolution is now well documented. However, the way they affect the transcriptome is still not clearly established. Using the sequenced genome of Drosophila melanogaster and EST libraries (“Expressed Sequence Tag”, large tags (~500bp) corresponding to subsequences of a transcribed cDNA sequences), we describe here the TE insertions that are unequivocally transcribed, and we have determined their location in the sequenced genome of Drosophila melanogaster. We show that most TE families are transcribed, and we have specifically identified 69 expressed TE insertions, half of which are located inside genes, mostly within introns and 5′UTRs regulatory regions.