Summary: Breast cancer (BC) is the most frequent cancer type in female population of Europe. Approximately 5 - 10 % accounts for its hereditary form which is characterized by high penetrance, early onset, risen recurrence risk and development of other cancers. Mutational analyses of high risk patients identify a predisposing mutation in one of the most studied genes (BRCA1, BRCA2, TP53, ATM, CHEK2, NBS1, PALB2) only in less than one third of tested breast cancer patients. Lately, with the use of new methods of next-generation sequencing, a number of other susceptibility or candidate genes were characterized, but the incidence of their pathogenic alteration is often geographically different. A notable proportion of high risk patients from families with hereditary BC can represent carriers of population-specific, or private mutations. Most of the to date identified BC susceptibility genes codes for proteins involved in DNA repair, especially repair of double strand break DNA repair. Nevertheless the mutation analysis was conducted only on a small fraction of these DNA repair genes. We can expect that in the group of yet nontested genes coding for DNA repair proteins a rare, but clinically important genetic alterations predisposing to BC in affected families can be discovered. This work describes a...

Next-Generation Sequencing (NGS) technologies have been evolving at an unparalleled pace. The ability to generate millions of base pairs of data in a short time and at lower cost than previously has led to a dramatic expansion of technologies within the field. This dissertation discusses the development and validation of new methods for assessing genomic variation, dynamic changes in gene expression, high-accuracy sequencing, and analysis of recombination events. By reducing the cost of analyzing many samples for genetic divergence by genotyping the same region of the genome in multiple samples, researchers can pursue investigations on a larger scale. Next-RAD (Nextera fragmentation with Restriction-Associated Digestion) allows analysis of a uniform subset of loci between organisms for comparison of populations by genetic differences with reduced burdens of cost and data analysis. This method was applied to the Anopheles darlingi mosquito to identify three distinct species that were thought to be a uniform population. The lowering cost of large-scale sequencing investigations allows for massively parallel analysis of genomic function in a single assay. Regulation of gene expression in response to stress is a complex process which can only be understood by analyzing many pathways in tandem. A novel method is described which quantifies on a genome-wide scale the expression of millions of randomer tags driven by associated transcriptional enhancers. This method provides novel data in the form of high-resolution analysis of gene regulation. Aside from generating novel data types, another force behind development of new technologies is to improve data quality. One limitation of NGS is the inherent error rate. PELE-Seq (Paired End Low Error Sequencing) was developed to address this problem, by employing completely overlapping paired-end reads as well as a dual barcoding strategy to eliminate incorrect sequences resulting from final library amplification. This new tool improves data quality dramatically. Finally, the rapid expansion of tools necessitates the identification of new applications for these technologies. To this end, 10x Genomics Linked-Read sequencing was employed to identify recombination events in multiple species. The haplotype-resolved nature of the data generated from such assays has many promising applications.

Breast cancer is a clinically and molecularly heterogeneous disease displaying distinct therapeutic responses. Although recent studies have explored the genomic and transcriptomic landscapes of breast cancer, the epigenetic architecture has received less attention. To address this, an optimised Reduced Representation Bisulfite Sequencing protocol was performed on 1482 primary breast tumours (and 237 matched adjacent normal tissues). This constitutes the largest breast cancer methylome yet, and this thesis describes the bioinformatics and statistical analysis of this study. Noticeable epigenetic drift (both gain and loss of homogeneous DNA methylation patterns) was observed in breast tumours when compared to normal tissues, with markedly higher differences in late replicating genomic regions. The extent of epigenetic drift was also found to be highly heterogeneous between the breast tumours and was sharply correlated with the tumour’s mitotic index, indicating that epigenetic drift is largely a consequence of the accumulation of passive cell division related errors. A novel algorithm called DMARC (Directed Methylation Altered Regions in Cancer) was developed that utilised the tumour-specific drift rates to discriminate between methylation alterations attained as a consequence of stochastic cell division errors (background) and those reflecting a more instructive biological process (directed). Directed methylation alterations were significantly enriched for gene expression changes in breast cancer, compared to background alterations. Characterising these methylation aberrations with gene expression led to the identification of breast cancer subtype-specific epigenetic genes with consequences on transcription and prognosis. Cancer genes may be deregulated by multiple mechanisms. By integrating with existing copy number and gene expression profiles for these tumours, DNA methylation alterations were revealed as the predominant mechanism correlated with differentially expressed genes in breast cancer. The crucial role of DNA methylation as a mechanism to target the silencing of specific genes within copy number amplifications is also explored which led to the identification of a putative tumour suppressor gene, THSZ2. Finally, the first genome-wide assessment of epigenomic evolution in breast cancer is conducted. Both, the level of intratumoural heterogeneity, and the extent of epiallelic burden were found to be prognostic, and revealed an extraordinary distinction in the role of epiclonal dynamics in different breast cancer subtypes. Collectively, the results presented in this thesis have shed light on the somatic DNA methylation basis of inter-patient as well as intra-tumour heterogeneity in breast cancer. This complements our genetic knowledge of the disease, and will help move us towards tailoring treatments to the patient's molecular profile.

Sepsis is one of the leading causes for fatalities in the intensive care unit, and also one of the biggest health problems worldwide. It is a disease caused primarily by bacterial infections but can also be caused by viral or fungal infections. Since it is such a big health problem being associated with increased risk of sepsis, coupled with longer stays in the intensive care unit, the need for fast diagnosis and treatment is very important. Currently, culture is the leading diagnostic method for identification of bacteria, although other methods are currently being tested to improve identification time and decrease cost and workload. Next generation sequencing (NGS) has the capacity to output several million reads in a single experiment, making it very fast and relatively cheap compared to other older sequencing methods such as Sanger sequencing. The ability to analyze genes and even whole genomes, opens the possibilities to identify factors such as bacterial species, virulence genes and antibiotic resistance genes. The aim of this study was to find any possible correlations between 16 species of streptococci and clinical data in patients with suspected sepsis. Initial species identification was performed using MALDI-TOF before the samples were sequenced using NGS. Sequence files were then quality controlled and trimmed before being assembled. Following assembly, coverage was controlled for all assembled genomes before the downstream analysis started. Different tools such as 16S RNA species identification, multi locus sequence typing and antibiotic resistance finder were used, among other tools. The results were extremely mixed, with the overall quality of the data being of good quality, but the assembly and downstream analysis being worse. The most consistent species was S. pyogenes. No correlation between sepsis patients and relevant clinical data was found. The mixed quality of results from assembly and downstream analysis were most likely contributed to difficulties in culturing and sequencing of the streptococci. Finding ways to circumvent these problems would most likely aid in general sequencing of streptococcal species, and hopefully in clinical applications as well.

abstract: Rapid advancements in genomic technologies have increased our understanding of rare human disease. Generation of multiple types of biological data including genetic variation from genome or exome, expression from transcriptome, methylation patterns from epigenome, protein complexity from proteome and metabolite information from metabolome is feasible. "Omics" tools provide comprehensive view into biological mechanisms that impact disease trait and risk. In spite of available data types and ability to collect them simultaneously from patients, researchers still rely on their independent analysis. Combining information from multiple biological data can reduce missing information, increase confidence in single data findings, and provide a more complete view of genotype-phenotype correlations. Although rare disease genetics has been greatly improved by exome sequencing, a substantial portion of clinical patients remain undiagnosed. Multiple frameworks for integrative analysis of genomic and transcriptomic data are presented with focus on identifying functional genetic variations in patients with undiagnosed, rare childhood conditions. Direct quantitation of X inactivation ratio was developed from genomic and transcriptomic data using allele specific expression and segregation analysis to determine magnitude and inheritance mode of X inactivation. This approach was applied in two families revealing non-random X inactivation in female patients. Expression based analysis of X inactivation showed high correlation with standard clinical assay. These findings improved understanding of molecular mechanisms underlying X-linked disorders. In addition multivariate outlier analysis of gene and exon level data from RNA-seq using Mahalanobis distance, and its integration of distance scores with genomic data found genotype-phenotype correlations in variant prioritization process in 25 families. Mahalanobis distance scores revealed variants with large transcriptional impact in patients. In this dataset, frameshift variants were more likely result in outlier expression signatures than other types of functional variants. Integration of outlier estimates with genetic variants corroborated previously identified, presumed causal variants and highlighted new candidate in previously un-diagnosed case. Integrative genomic approaches in easily attainable tissue will facilitate the search for biomarkers that impact disease trait, uncover pharmacogenomics targets, provide novel insight into molecular underpinnings of un-characterized conditions, and help improve analytical approaches that use large datasets. / Dissertation/Thesis / Doctoral Dissertation Molecular and Cellular Biology 2015

abstract: Obesity and its underlying insulin resistance are caused by environmental and genetic factors. DNA methylation provides a mechanism by which environmental factors can regulate transcriptional activity. The overall goal of the work herein was to (1) identify alterations in DNA methylation in human skeletal muscle with obesity and its underlying insulin resistance, (2) to determine if these changes in methylation can be altered through weight-loss induced by bariatric surgery, and (3) to identify DNA methylation biomarkers in whole blood that can be used as a surrogate for skeletal muscle. Assessment of DNA methylation was performed on human skeletal muscle and blood using reduced representation bisulfite sequencing (RRBS) for high-throughput identification and pyrosequencing for site-specific confirmation. Sorbin and SH3 homology domain 3 (SORBS3) was identified in skeletal muscle to be increased in methylation (+5.0 to +24.4 %) in the promoter and 5’untranslated region (UTR) in the obese participants (n= 10) compared to lean (n=12), and this finding corresponded with a decrease in gene expression (fold change: -1.9, P=0.0001). Furthermore, SORBS3 was demonstrated in a separate cohort of morbidly obese participants (n=7) undergoing weight-loss induced by surgery, to decrease in methylation (-5.6 to -24.2%) and increase in gene expression (fold change: +1.7; P=0.05) post-surgery. Moreover, SORBS3 promoter methylation was demonstrated in vitro to inhibit transcriptional activity (P=0.000003). The methylation and transcriptional changes for SORBS3 were significantly (P≤0.05) correlated with obesity measures and fasting insulin levels. SORBS3 was not identified in the blood methylation analysis of lean (n=10) and obese (n=10) participants suggesting that it is a muscle specific marker. However, solute carrier family 19 member 1 (SLC19A1) was identified in blood and skeletal muscle to have decreased 5’UTR methylation in obese participants, and this was significantly (P≤0.05) predicted by insulin sensitivity. These findings suggest SLC19A1 as a potential blood-based biomarker for obese, insulin resistant states. The collective findings of SORBS3 DNA methylation and gene expression present an exciting novel target in skeletal muscle for further understanding obesity and its underlying insulin resistance. Moreover, the dynamic changes to SORBS3 in response to metabolic improvements and weight-loss induced by surgery. / Dissertation/Thesis / Appendix A / Appendix B / Appendix C / Appendix D / Appendix G / Doctoral Dissertation Biology 2017

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response system and can occur when the immune system over- or under- reacts to an infection. Klebsiella spp. has been found to be one of the leading causes of sepsis, and the increasing occurrence of antibiotic resistance observed has become a major concern in clinical care. To study the genome and increase knowledge of the biodiversity of K. pneumoniae, K. variicola, and K. oxytoca, bacterial isolates were collected from blood, urine, nasopharynx, and wounds of patients with suspected sepsis. Next-generation sequencing was performed, and the presence of antibiotic resistance genes and plasmids were studied. Furthermore, a prediction of traits for each phylogroup was performed and the results from whole-genome sequencing were compared to phenotypic results. Among the K. pneumoniae isolates obtained, almost half had been misidentified by standard phenotypic methods and were found to be K. variicola, K. quasipneumoniae, and K. quasivariicola. A significant difference in the number of antibiotic resistance genes were observed between K. pneumoniae and K. variicola compared to K. oxytoca, however no significant difference was observed between K. pneumoniae and K. variicola, suggesting the underestimated pathogenicity of K. variicola. A genetic agreement was observed between the type of beta-lactamase harboured and presence or absence of nitrogen-fixation genes to the phylogroup, providing a way of species identification. Further studies should be conducted on the pathogenicity and virulence of K. variicola and K. quasipneumoniae to avoid misidentification, find organism-specific treatments, and narrow down the antibiotic prescription. / Biodiversitet vid Sepsis

Submitted by Guilherme Batista do Nascimento null (guilhermebn@msn.com) on 2018-03-16T12:24:54Z No. of bitstreams: 1 Tese_Guilherme_Batista_do_Nascimento.pdf: 1770231 bytes, checksum: ad03948ecc7b09b89d46d26b7c9e3bf8 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-03-16T19:03:02Z (GMT) No. of bitstreams: 1 nascimento_gb_dr_jabo.pdf: 1770231 bytes, checksum: ad03948ecc7b09b89d46d26b7c9e3bf8 (MD5) / Made available in DSpace on 2018-03-16T19:03:02Z (GMT). No. of bitstreams: 1 nascimento_gb_dr_jabo.pdf: 1770231 bytes, checksum: ad03948ecc7b09b89d46d26b7c9e3bf8 (MD5) Previous issue date: 2018-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A implementação de dados de sequenciamento de nova geração - “next-generation sequence” (NGS) em programas de melhoramento genético animal representa a mais recente ferramenta na utilização de dados genotípicos nos modelos de associação genômica, tendo em vista que todo polimorfismo é considerado nas associações entre registros fenotípicos e dados de sequenciamento. Como em toda nova tecnologia, a prospecção das variantes ainda representa um desafio no sentido computacional e de viabilidade dos custos para sua implementação em larga escala. Diante desses desafios, neste trabalho buscou-se meios de explorar os benefícios na utilização da NGS nas predições genômicas e superar as limitações inerentes a esse processo. Registros fenotípicos e genotípicos (Illumina Bovine HD BeadChip) de 2.279 animais da raça Gir (Bos taurus indicus) foram disponibilizados pela Embrapa Gado de Leite (MG) e utilizados para as análises de associação genômica. Além disso, dados de sequenciamento de 53 animais do 1000 “Bulls Project” deram origem à população de referência de imputação. Visando verificar a eficiência de imputação, foram testados diferentes cenários quanto a sua acurácia de imputação por meio da análise “leave-one-out”, utilizando apenas os dados de sequenciamento, que apresentaram eficiências de até 84%, no cenário com todos os 51 animais disponíveis após o controle de qualidade. Também foram verificadas as influências das variantes em baixa frequência na acurácia de imputação em diferentes regiões do genoma. Com a escolha da melhor estrutura da população de referência de imputação e aplicação dos controles de qualidade nos dados de NGS e genômicos, foi possível imputar os 2.237 animais genotipados, que passaram pelo controle de qualidade para dados de sequenciamento e realizar análise de associação genômica para as características produção de leite (PL305), teor de gordura (PG305), proteína (PP305) e sólidos totais (PS305), mensuradas aos 305 dias em animais da raça Gir leiteiro. Para tal, foram utilizados os valores genéticos desregredidos (dEBV) como variável resposta no modelo de regressão múltipla. Regiões de 1Mb que contivessem 100 ou mais variantes com “False Discovery Rate” (FDR) inferior a 0,05, foram consideradas significativas e submetidas a análise de enriquecimento por meio dos termos MeSh (“Medical Subject Headings”). As três regiões significativas (FDR<0,05) para PS305 foram observadas nos cromossomos 11, 12 e 28 e a única região significativa em PG305 foi no cromossomo 6. Tais regiões apresentaram variantes associadas com vias metabólicas da produção de leite, ausentes nos painéis comerciais de genotipagem, podendo representar genes candidatos a seleção. / - Implementing "next-generation sequence" (NGS) data in animal breeding programs represents the latest tool in the use of genotypic data in genomic association models, since all polymorphisms are considered in the associations between phenotypic records and sequencing data. As with any new technology, variant prospecting still represents a computational and cost-effective challenge for large-scale implementation. Front to these challenges, this work sought ways to explore the benefits of using NGS in genomic predictions and overcome the inherent limitations of this process. Phenotypic and genotypic (Illumina Bovine HD BeadChip) records of 2,279 Gir animals (Bos taurus indicus) were made available by Embrapa Gado de Leite (MG) and used for genomic association analysis. In addition, sequence data of 53 animals from the 1000 Bulls Project gave rise to the imputation reference population. In order to verify the imputation efficiency, different scenarios were tested for their imputation accuracy through the leave-one-out analysis, using only the sequencing data, which presented efficiencies of up to 84%, in the scenario with all the 51 animals available after quality control. Influences from the low-frequency variants on the accuracy of imputation in different regions of the genome were also verified. After identifying the best reference population structure of imputation and applying the quality controls in the NGS and genomic data, it was possible to impute the 2 237 genotyped animals that passed in the quality control to sequencing data and perform genomic association analysis for (PL305), fat content (PG305), protein (PP305) and total solids (PS305), measured at 305 days in dairy Gir animals. For this, unregulated genetic values (dEBV) were used as response variable in the multiple regression model. Regions of 1Mb containing 100 or more variants with a False Discovery Rate (FDR) lower than 0.05 were considered statistically significant and submitted to pathways enrichment analysis using the MeSh (Medical Subject Headings) terms. The three significant regions (FDR <0.05) for PS305 were observed on chromosomes 11, 12 and 28 and only one significant region in PG305, was on chromosome 6. These regions presented variants associated with metabolic pathways of milk production, absent in the panels genotyping, and may represent genes that are candidates for selection / convênio Capes/Embrapa (edital 15/2014)

Submitted by RENATA ZUGAIB null (rzugaib@gmail.com) on 2017-01-20T15:02:38Z No. of bitstreams: 1 Dissertação Renata - Defesa.pdf: 1638667 bytes, checksum: f166690438b6f00c2e9fe2b0da55497d (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-01-24T18:09:13Z (GMT) No. of bitstreams: 1 zugaib_r_me_bot.pdf: 1638667 bytes, checksum: f166690438b6f00c2e9fe2b0da55497d (MD5) / Made available in DSpace on 2017-01-24T18:09:13Z (GMT). No. of bitstreams: 1 zugaib_r_me_bot.pdf: 1638667 bytes, checksum: f166690438b6f00c2e9fe2b0da55497d (MD5) Previous issue date: 2017-01-13 / O vírus da hepatite C (VHC) constitui a principal causa de doença hepática crônica, que representa um dos maiores problemas de saúde pública. O carcinoma hepatocelular (CHC), altamente associado a infecção crônica pelo vírus da hepatite C (VHC), é um dos tumores malignos mais comuns no mundo, com um alto índice de causa de óbito. Com o avanço das técnicas moleculares, tornou-se possível uma nova abordagem nos estudos gênicos para um melhor entendimento molecular de processos infecciosos e crônicos. Estudos evidenciando uma associação da transcrição gênica ao processo patológico e a importância de análises mais abrangentes. O sequenciamento de nova geração fornece uma maneira poderosa para a avaliação global do transcriptoma com alta resolução e um menor custo, possibilitando uma análise do perfil transcricional da doença. Assim, este estudo teve por objetivo avaliar o perfil de expressão gênica diferencial de pacientes infectados pelo VHC com CHC e comparar com amostras de tecidos não tumorais através do sequenciamento em larga escala do transcriptoma, a fim de identificar potenciais biomarcadores de diagnóstico e prognóstico de CHC. Foram analisados três fragmentos de tecido tumoral e três fragmentos de tecido hepático não tumoral como controle através do sequenciamento de RNAs (RNA-Seq). Os resultados obtidos demonstraram uma expressão diferencial de 4.792 genes. Avaliando os 10 genes mais e menos expressos, foi observada uma grande associação de variações nesses genes em diversos tipos de tumores. Também foram observados, entre os menos expressos, genes intimamente relacionados a função hepática ou relacionados a componentes produzidos pelo fígado. Esses achados sugerem que COL11A1, SFRP4, SFRP2, LRRC15, CCL18, ADAMDEC1, COL1A1, COL10A1, CTHRC1 e OLR1, superexpressos, possam atuar juntos no processo tumoral servindo como marcadores moleculares tumorais, e que a presença do tumor possa provocar uma desregulação nos genes associados ao fígado aqui encontrados, contudo, estudos mais específicos devem ser conduzidos para a confirmação dessa hipótese. / Hepatitis C virus (HCV) is the leading cause of chronic liver disease, one of the major public health problems. Hepatocellular carcinoma (HCC), highly associated with chronic hepatitis C virus (HCV) infection, is one of the most common malignant tumors in the world, with a high cause of death. With the advancement of molecular techniques, a new approach in gene studies has become possible for a better molecular understanding of infectious and chronic processes. Studies evidencing an association of the gene transcription to the pathological process and the importance of more comprehensive analyzes. Next generation sequencing provides a powerful way for the global evaluation of the transcriptome with high resolution and a lower cost, allowing an analysis of the transcriptional profile of the disease. Thus, this study aimed to evaluate the differential gene expression profile of HCV infected patients in their highest degree of chronicity (HCC) and to compare with non-tumor tissue samples through large-scale sequencing of the transcriptome in order to identify potential biomarkers for diagnosis and prognosis of HCC. Three fragments of tumor tissue and three fragments of non-tumor liver tissue were analyzed through the sequencing of RNAs (RNA-Seq). The results obtained demonstrated a differential expression of 4.792 genes. Evaluating the 10 over and down regulated genes, a high association of variations in these genes was observed in several types of tumors. Among the least expressed, genes closely related to liver function or related to components produced by the liver were also observed. These findings suggest that COL11A1, SFRP4, SFRP2, LRRC15, CCL18, ADAMDEC1, COL1A1, COL10A1, CTHRC1 and OLR1, overexpressed, may act together in the tumor process serving as molecular tumor markers, and that the presence of the tumor may lead to dysregulation in the genes associated with the liver found here, however, more specific studies should be conducted to confirm this hypothesis.

abstract: Photosynthesis is the primary source of energy for most living organisms. Light harvesting complexes (LHC) play a vital role in harvesting sunlight and passing it on to the protein complexes of the electron transfer chain which create the electrochemical potential across the membrane which drives ATP synthesis. phycobilisomes (PBS) are the most important LHCs in cyanobacteria. PBS is a complex of three light harvesting proteins: phycoerythrin (PE), phycocyanin (PC) and allophycocyanin (APC). This work has been done on a newly discovered cyanobacterium called Leptolyngbya Heron Island (L.HI). This study has three important goals: 1) Sequencing, assembly and annotation of the L.HI genome - Since this is a newly discovered cyanobacterium, its genome was not previously elucidated. Illumina sequencing, a type of next generation sequencing (NGS) technology was employed to sequence the genome. Unfortunately, the natural isolate contained other contaminating and potentially symbiotic bacterial populations. A novel bioinformatics strategy for separating DNA from contaminating bacterial populations from that of L.HI was devised which involves a combination of tetranucleotide frequency, %(G+C), BLAST analysis and gene annotation. 2) Structural elucidation of phycoerythrin - Phycoerythrin is the most important protein in the PBS assembly because it is one of the few light harvesting proteins which absorbs green light. The protein was crystallized and its structure solved to a resolution of 2Å. This protein contains two chemically distinct types of chromophores: phycourobilin and phycoerythrobilin. Energy transfer calculations indicate that there is unidirectional flow of energy from phycourobilin to phycoerythrobilin. Energy transfer time constants using Forster energy transfer theory have been found to be consistent with experimental data available in literature. 3) Effect of chromatic acclimation on photosystems - Chromatic acclimation is a phenomenon in which an organism modulates the ratio of PE/PC with change in light conditions. Our investigation in case of L.HI has revealed that the PE is expressed more in green light than PC in red light. This leads to unequal harvesting of light in these two states. Therefore, photosystem II expression is increased in red-light acclimatized cells coupled with an increase in number of PBS. / Dissertation/Thesis / Ph.D. Chemistry 2014