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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

PRESENCE OF NEGLECTED BACTERIA IN THE INFANT GUT MICROBIOTA

SAGHEDDU, VALERIA 31 May 2017 (has links)
Il tratto gastro intestinale infantile al momento del parto è considerato virtualmente sterile e viene rapidamente colonizzato da microrganismi di origine materna e/o ambientale nei primi giorni di vita. Studi accoppiati di microbiologia classica e molecolare hanno dimostrato come la cavità amniotica sia popolata da microrganismi alcuni dei quali appartenenti a taxa non ancora coltivati e caratterizzati. Lo scopo del presente lavoro di tesi è stato quello di valutare la composizione del microbiota infantile durante i primi due anni di vita, in particolare, di popolazioni parzialmente “trascurate”. La tesi è suddivisibile in tre tematiche principali: presenza di popolazioni idrogenotrofiche, la distribuzione della famiglia delle Lachnospiraceae in soggetti sani prima del secondo anno di vita, e la possibile correlazione tra gli archaea metanogeni e la dieta in modello animale. Le tecniche impiegate nel presente lavoro di tesi sono state la PCR-DGGE e la PCR quantitativa (qPCR) e il sequenziamento Illumina. Le principali conclusioni derivabili dai tre studi sono correlate alla necessità di sviluppare nuove coppie di primers che meglio possano descrivere la complessa ecologia delle comunità microbiche intestinali. L’ambizioso obiettivo potrà considerarsi raggiunto quando si potranno identificare e stimare in modo preciso e corretto anche le popolazioni batteriche poco abbondanti nel microbiota intestinale infantile. / At birth, the gastrointestinal tract is virtually sterile, but is rapidly colonized during the first days of life until a relatively stable state is reached. Several studies using both bacterial culture techniques and bio-molecular methods revealed that the amniotic cavity harbors microorganisms and, among them, uncultivated and uncharacterized taxa. The aim of the present PhD thesis was to evaluate the composition of some neglected populations inhabiting the infant gut microbiota until the second year of life. The PhD thesis is composed of three main chapters related to the presence of hydrogenotrophic populations, the occurrence of the Lachnospiraceae family in healthy subjects before the second year and the possible linkage between methanogens and diet in a piglet’s model. PCR-DGGE, the quantitative PCR (qPCR) and the Illumina deep sequencing have been the prevalent molecular techniques used in this work. Main conclusions obtained from these studies were mainly linked to the need of new primer sets that better describe the ecological complexity of the gut microbial community. This ambitious objective will be reached when it is possible to properly identify and quantify less represented bacterial populations within the infant gut ecosystem.
22

Isolamento e caracterização de um novo vírus gigante de amebas : Golden mussel marseillevirus / Isolation and characterization of a new giant virus in amoebae : Golden mussel marseillevirus

Santos, Raíssa Nunes dos January 2016 (has links)
Marseilleviridae é uma família de vírus gigantes cujos membros infectam amebas de vida livre. Esses vírus têm sido encontrados em amostras ambientais de água, larvas de inseto, torres de resfriamento e mais recentemente em amostras humanas. Eles possuem capsídeo icosaédrico medindo entre 190-250 nm e genoma de DNA dupla fita circular ou linear. Sua replicação ocorre no citoplasma amebiano onde observam-se fábricas virais. Este trabalho tem como objetivo investigar a presença de vírus gigantes em mexilhões-dourados (Limnoperna fortunei) que habitam o Lago Guaíba, Porto Alegre, Brasil. Quarenta indivíduos foram coletados e agrupados em pools de 5 amostras (água interna e corpo, totalizando dezesseis pools). Os pools foram homogeneizados em tampão fosfato, centrifugados e o sobrenadante filtrado em membrana de 0,45μM. Foram cultivadas amebas da espécie Acanthamoeba polyphaga em meio PYG em microplacas de 24 poços, inoculadas com os sobrenadantes, incubadas a 30ºC e examinadas diariamente em busca de efeito citopático (ECP) até 72 horas após a inoculação. Quando CPE era evidente, os sobrenadantes foram coletados e ultracentrifugados através de um gradiente de sacarose de 25%. Um dos dezesseis pools induzindo CPE claro foi submetido à extração de DNA e sequenciamento do genoma viral completo um sequenciador de nova geração (Illumina MiSeq). O genoma do vírus chamado Golden mussel marseillevirus consiste de uma única molécula de DNA de 360610 pb, com um teor de G+C de 43,1%. A análise da sequência de nucleotídeos traduzida revelou a presença de proteínas virais que apresentam homologia com proteínas de outros membros da família Marseilleviridae, como Lausanevirus e vírus Insectomime, porém grande parte do seu genoma não apresenta identidade com proteínas depositadas no banco de dados. A análise filogenética do gene D6/D11 Helicase sugere que este vírus faça parte de uma nova linhagem de marseillevirus. Este é o primeiro estudo que demonstra o isolamento de um vírus gigante a partir de tecidos de mexilhão-dourado e infere que estes vírus estão distribuídos amplamente no meio ambiente. / Marseilleviridae is a family of giant viruses whose members infect free living amoebae. These viruses have been found in environmental samples of water, insect larvae, cooling towers and, more recently, in human samples. They have icosahedral capsids measuring between 190-250 nm and their genome is double-stranded circular or linear DNA. Replication occurs in the host cell cytoplasm, inside the viral factories. This study aims to investigate the presence of giant viruses in tissues of golden mussels (Limnoperna fortunei) that inhabit the Guaiba Lake, Porto Alegre, Brazil. Forty specimens were pooled in groups of 5 specimens (internal water and body, totalizing sixteen pools). The pools were homogenized with phosphate buffer, centrifuged and the supernatant was filtered in 0,45μM. Monolayers of Acanthamoeba polyphaga were cultivated with PYG medium in 24-well microplates, inoculated with the pooled samples, incubated at 30 ºC and examined daily in search for cytopathic effect (CPE) up to 72 hours after inoculation. When CPE was evident, the supernatants were collected, clarified and ultra centrifuged through a 25% sucrose cushion. One out of the sixteen CPE positive pools was submitted to DNA extraction and complete sequencing of the viral genome in a NGS apparatus (Illumina MiSeq). The genome of the virus named Golden mussel marseillevirus consists of a single DNA molecule of 360,610 bp, with a G+C content of 43.1%. The analysis of the translated nucleotide sequence reveals the presence of proteins which are homologs to proteins predicted in other members of the family Marseilleviridae like, e.g. Lausannevirus and Isectomime virus. However, part of the viral genome has no identity with the nucleotide sequences available at the database. The phylogenetic analysis of the D6/D11 Helicase gene suggests that this virus is part of a new lineage of marseillevirus. This is the first study where the isolation of a giant virus from golden mussel tissues is achieved, suggesting that these viruses are widely distributed in the environment.
23

THE ROLE OF POLYADENYLATION IN SEED GERMINATION

Ma, Liuyin 01 January 2013 (has links)
Seed germination has many impacts on the uses of seeds, and is an important subject for study. Seed germination is regulated at both transcriptional and post-transcriptional levels. Therefore, it is important to study how polyadenylation regulates gene expression during seed germination. To this end, a modified Illumina GAIIx sequencing protocol (described in Chapter Two) was developed that allows deep coverage of poly(A) site position and distribution. Alternative polyadenylation (APA) regulates gene expression by choosing one potential poly(A) site on a precursor RNA consequentially shortening/lengthening the mRNA relative to other possible sites. To further explore this phenomenon, genes affected by APA during seed germination and other developmental stages were identified (Chapter Three). These genes were categorized based on the location of poly(A) sites. Several genes were chosen to demonstrate how APA, especially that occurring in the coding regions and 5’ untranslated regions, might down regulate gene expression by generating truncated transcripts. In animal oocytes, maternally-derived mRNAs are stored with short poly(A) tails and reactivated by the cytoplasmic polyadenylation complex. It has been reported that seeds also contain stored mRNAs. Moreover, germination and its completion are less sensitive to de novo transcription inhibitors than to poly(A) polymerase inhibitors. Together, these considerations suggest that stored RNA without or with a short poly(A) tail (stored, unadenylated RNA) may be present in dry seed and function in seed germination upon reactivation by cytoplasmic polyadenylation. To further explore this, in Chapter Four, mRNA polyadenylation was studied through the course of germination using a combination of transcriptional inhibitors and the modified sequencing protocol described in Chapter Two. 273 putative stored, unadenylated RNAs were identified. Gene ontology analysis revealed that genes whose products are involved in translation are overrepresented; these genes encode 21 60S- and 10 40S-ribosomal proteins. These results indicate that transcripts whose products are involved in translation might be a major component of the stored, unadenylated RNA pool and, more importantly, translation might be the first cellular process to be activated during seed germination.
24

Massively parallel analysis of cells and nucleic acids

Sandberg, Julia January 2011 (has links)
Recent proceedings in biotechnology have enabled completely new avenues in life science research to be explored. By allowing increased parallelization an ever-increasing complexity of cell samples or experiments can be investigated in shorter time and at a lower cost. This facilitates for example large-scale efforts to study cell heterogeneity at the single cell level, by analyzing cells in parallel that also can include global genomic analyses. The work presented in this thesis focuses on massively parallel analysis of cells or nucleic acid samples, demonstrating technology developments in the field as well as use of the technology in life sciences. In stem cell research issues such as cell morphology, cell differentiation and effects of reprogramming factors are frequently studied, and to obtain information on cell heterogeneity these experiments are preferably carried out on single cells. In paper I we used a high-density microwell device in silicon and glass for culturing and screening of stem cells. Maintained pluripotency in stem cells from human and mouse was demonstrated in a screening assay by antibody staining and the chip was furthermore used for studying neural differentiation. The chip format allows for low sample volumes and rapid high-throughput analysis of single cells, and is compatible with Fluorescence Activated Cell Sorting (FACS) for precise cell selection. Massively parallel DNA sequencing is revolutionizing genomics research throughout the life sciences by constantly producing increasing amounts of data from one sequencing run. However, the reagent costs and labor requirements in current massively parallel sequencing protocols are still substantial. In paper II-IV we have focused on flow-sorting techniques for improved sample preparation in bead-based massive sequencing platforms, with the aim of increasing the amount of quality data output, as demonstrated on the Roche/454 platform. In paper II we demonstrate a rapid alternative to the existing shotgun sample titration protocol and also use flow-sorting to enrich for beads that carry amplified template DNA after emulsion PCR, thus obtaining pure samples and with no downstream sacrifice of DNA sequencing quality. This should be seen in comparison to the standard 454-enrichment protocol, which gives rise to varying degrees of sample purity, thus affecting the sequence data output of the sequencing run. Massively parallel sequencing is also useful for deep sequencing of specific PCR-amplified targets in parallel. However, unspecific product formation is a common problem in amplicon sequencing and since these shorter products may be difficult to fully remove by standard procedures such as gel purification, and their presence inevitably reduces the number of target sequence reads that can be obtained in each sequencing run. In paper III a gene-specific fluorescent probe was used for target-specific FACS enrichment to specifically enrich for beads with an amplified target gene on the surface. Through this procedure a nearly three-fold increase in fraction of informative sequences was obtained and with no sequence bias introduced. Barcode labeling of different DNA libraries prior to pooling and emulsion PCR is standard procedure to maximize the number of experiments that can be run in one sequencing lane, while also decreasing the impact of technical noise. However, variation between libraries in quality and GC content affects amplification efficiency, which may result in biased fractions of the different libraries in the sequencing data. In paper IV barcode specific labeling and flow-sorting for normalization of beads with different barcodes on the surface was used in order to weigh the proportion of data obtained from different samples, while also removing mixed beads, and beads with no or poorly amplified product on the surface, hence also resulting in an increased sequence quality. In paper V, cell heterogeneity within a human being is being investigated by low-coverage whole genome sequencing of single cell material. By focusing on the most variable portion of the human genome, polyguanine nucleotide repeat regions, variability between different cells is investigated and highly variable polyguanine repeat loci are identified. By selectively amplifying and sequencing polyguanine nucleotide repeats from single cells for which the phylogenetic relationship is known, we demonstrate that massively parallel sequencing can be used to study cell-cell variation in length of these repeats, based on which a phylogenetic tree can be drawn. / QC 20111031
25

Isolamento e caracterização de um novo vírus gigante de amebas : Golden mussel marseillevirus / Isolation and characterization of a new giant virus in amoebae : Golden mussel marseillevirus

Santos, Raíssa Nunes dos January 2016 (has links)
Marseilleviridae é uma família de vírus gigantes cujos membros infectam amebas de vida livre. Esses vírus têm sido encontrados em amostras ambientais de água, larvas de inseto, torres de resfriamento e mais recentemente em amostras humanas. Eles possuem capsídeo icosaédrico medindo entre 190-250 nm e genoma de DNA dupla fita circular ou linear. Sua replicação ocorre no citoplasma amebiano onde observam-se fábricas virais. Este trabalho tem como objetivo investigar a presença de vírus gigantes em mexilhões-dourados (Limnoperna fortunei) que habitam o Lago Guaíba, Porto Alegre, Brasil. Quarenta indivíduos foram coletados e agrupados em pools de 5 amostras (água interna e corpo, totalizando dezesseis pools). Os pools foram homogeneizados em tampão fosfato, centrifugados e o sobrenadante filtrado em membrana de 0,45μM. Foram cultivadas amebas da espécie Acanthamoeba polyphaga em meio PYG em microplacas de 24 poços, inoculadas com os sobrenadantes, incubadas a 30ºC e examinadas diariamente em busca de efeito citopático (ECP) até 72 horas após a inoculação. Quando CPE era evidente, os sobrenadantes foram coletados e ultracentrifugados através de um gradiente de sacarose de 25%. Um dos dezesseis pools induzindo CPE claro foi submetido à extração de DNA e sequenciamento do genoma viral completo um sequenciador de nova geração (Illumina MiSeq). O genoma do vírus chamado Golden mussel marseillevirus consiste de uma única molécula de DNA de 360610 pb, com um teor de G+C de 43,1%. A análise da sequência de nucleotídeos traduzida revelou a presença de proteínas virais que apresentam homologia com proteínas de outros membros da família Marseilleviridae, como Lausanevirus e vírus Insectomime, porém grande parte do seu genoma não apresenta identidade com proteínas depositadas no banco de dados. A análise filogenética do gene D6/D11 Helicase sugere que este vírus faça parte de uma nova linhagem de marseillevirus. Este é o primeiro estudo que demonstra o isolamento de um vírus gigante a partir de tecidos de mexilhão-dourado e infere que estes vírus estão distribuídos amplamente no meio ambiente. / Marseilleviridae is a family of giant viruses whose members infect free living amoebae. These viruses have been found in environmental samples of water, insect larvae, cooling towers and, more recently, in human samples. They have icosahedral capsids measuring between 190-250 nm and their genome is double-stranded circular or linear DNA. Replication occurs in the host cell cytoplasm, inside the viral factories. This study aims to investigate the presence of giant viruses in tissues of golden mussels (Limnoperna fortunei) that inhabit the Guaiba Lake, Porto Alegre, Brazil. Forty specimens were pooled in groups of 5 specimens (internal water and body, totalizing sixteen pools). The pools were homogenized with phosphate buffer, centrifuged and the supernatant was filtered in 0,45μM. Monolayers of Acanthamoeba polyphaga were cultivated with PYG medium in 24-well microplates, inoculated with the pooled samples, incubated at 30 ºC and examined daily in search for cytopathic effect (CPE) up to 72 hours after inoculation. When CPE was evident, the supernatants were collected, clarified and ultra centrifuged through a 25% sucrose cushion. One out of the sixteen CPE positive pools was submitted to DNA extraction and complete sequencing of the viral genome in a NGS apparatus (Illumina MiSeq). The genome of the virus named Golden mussel marseillevirus consists of a single DNA molecule of 360,610 bp, with a G+C content of 43.1%. The analysis of the translated nucleotide sequence reveals the presence of proteins which are homologs to proteins predicted in other members of the family Marseilleviridae like, e.g. Lausannevirus and Isectomime virus. However, part of the viral genome has no identity with the nucleotide sequences available at the database. The phylogenetic analysis of the D6/D11 Helicase gene suggests that this virus is part of a new lineage of marseillevirus. This is the first study where the isolation of a giant virus from golden mussel tissues is achieved, suggesting that these viruses are widely distributed in the environment.
26

Isolamento e caracterização de um novo vírus gigante de amebas : Golden mussel marseillevirus / Isolation and characterization of a new giant virus in amoebae : Golden mussel marseillevirus

Santos, Raíssa Nunes dos January 2016 (has links)
Marseilleviridae é uma família de vírus gigantes cujos membros infectam amebas de vida livre. Esses vírus têm sido encontrados em amostras ambientais de água, larvas de inseto, torres de resfriamento e mais recentemente em amostras humanas. Eles possuem capsídeo icosaédrico medindo entre 190-250 nm e genoma de DNA dupla fita circular ou linear. Sua replicação ocorre no citoplasma amebiano onde observam-se fábricas virais. Este trabalho tem como objetivo investigar a presença de vírus gigantes em mexilhões-dourados (Limnoperna fortunei) que habitam o Lago Guaíba, Porto Alegre, Brasil. Quarenta indivíduos foram coletados e agrupados em pools de 5 amostras (água interna e corpo, totalizando dezesseis pools). Os pools foram homogeneizados em tampão fosfato, centrifugados e o sobrenadante filtrado em membrana de 0,45μM. Foram cultivadas amebas da espécie Acanthamoeba polyphaga em meio PYG em microplacas de 24 poços, inoculadas com os sobrenadantes, incubadas a 30ºC e examinadas diariamente em busca de efeito citopático (ECP) até 72 horas após a inoculação. Quando CPE era evidente, os sobrenadantes foram coletados e ultracentrifugados através de um gradiente de sacarose de 25%. Um dos dezesseis pools induzindo CPE claro foi submetido à extração de DNA e sequenciamento do genoma viral completo um sequenciador de nova geração (Illumina MiSeq). O genoma do vírus chamado Golden mussel marseillevirus consiste de uma única molécula de DNA de 360610 pb, com um teor de G+C de 43,1%. A análise da sequência de nucleotídeos traduzida revelou a presença de proteínas virais que apresentam homologia com proteínas de outros membros da família Marseilleviridae, como Lausanevirus e vírus Insectomime, porém grande parte do seu genoma não apresenta identidade com proteínas depositadas no banco de dados. A análise filogenética do gene D6/D11 Helicase sugere que este vírus faça parte de uma nova linhagem de marseillevirus. Este é o primeiro estudo que demonstra o isolamento de um vírus gigante a partir de tecidos de mexilhão-dourado e infere que estes vírus estão distribuídos amplamente no meio ambiente. / Marseilleviridae is a family of giant viruses whose members infect free living amoebae. These viruses have been found in environmental samples of water, insect larvae, cooling towers and, more recently, in human samples. They have icosahedral capsids measuring between 190-250 nm and their genome is double-stranded circular or linear DNA. Replication occurs in the host cell cytoplasm, inside the viral factories. This study aims to investigate the presence of giant viruses in tissues of golden mussels (Limnoperna fortunei) that inhabit the Guaiba Lake, Porto Alegre, Brazil. Forty specimens were pooled in groups of 5 specimens (internal water and body, totalizing sixteen pools). The pools were homogenized with phosphate buffer, centrifuged and the supernatant was filtered in 0,45μM. Monolayers of Acanthamoeba polyphaga were cultivated with PYG medium in 24-well microplates, inoculated with the pooled samples, incubated at 30 ºC and examined daily in search for cytopathic effect (CPE) up to 72 hours after inoculation. When CPE was evident, the supernatants were collected, clarified and ultra centrifuged through a 25% sucrose cushion. One out of the sixteen CPE positive pools was submitted to DNA extraction and complete sequencing of the viral genome in a NGS apparatus (Illumina MiSeq). The genome of the virus named Golden mussel marseillevirus consists of a single DNA molecule of 360,610 bp, with a G+C content of 43.1%. The analysis of the translated nucleotide sequence reveals the presence of proteins which are homologs to proteins predicted in other members of the family Marseilleviridae like, e.g. Lausannevirus and Isectomime virus. However, part of the viral genome has no identity with the nucleotide sequences available at the database. The phylogenetic analysis of the D6/D11 Helicase gene suggests that this virus is part of a new lineage of marseillevirus. This is the first study where the isolation of a giant virus from golden mussel tissues is achieved, suggesting that these viruses are widely distributed in the environment.
27

Imputação e estudos genômicos de bovinos Nelore / Imputation and genomic studies in bovine Nelore

Bernardes, Priscila Arrigucci 29 June 2018 (has links)
Submitted by Priscila Arrigucci Bernardes (p.arrigucci@yahoo.com.br) on 2018-07-25T18:53:46Z No. of bitstreams: 1 Tese_Priscila_Arrigucci_Bernardes.pdf: 3025957 bytes, checksum: 866a988a470ab68070a7e7a922fc2993 (MD5) / Approved for entry into archive by Karina Gimenes Fernandes null (karinagi@fcav.unesp.br) on 2018-07-26T10:33:53Z (GMT) No. of bitstreams: 1 bernardes_pa_dr_jabo.pdf: 3025957 bytes, checksum: 866a988a470ab68070a7e7a922fc2993 (MD5) / Made available in DSpace on 2018-07-26T10:33:53Z (GMT). No. of bitstreams: 1 bernardes_pa_dr_jabo.pdf: 3025957 bytes, checksum: 866a988a470ab68070a7e7a922fc2993 (MD5) Previous issue date: 2018-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dentre as informações fornecidas pelas metodologias que utilizam marcadores do tipo polimorfismo de nucleotídeo único (SNPs), as de segmentos de homozigose (ROH) e de desequilíbrio de ligação têm colaborado para estudos de aplicação direta da informação genômica em populações de bovinos de corte, como em estudos de associação com cobertura ampla do genoma, de seleção genômica e de estrutura da população, dentre outros. Atualmente a imputação vem sendo utilizada principalmente para reduzir custos com a genotipagem dos animais e pode ser utilizada combinando informações genômicas de diferentes painéis. Para que dados imputados sejam utilizados de forma eficiente, é necessário que a imputação tenha sido implementada de forma que todos os animais tenham seus genótipos inferidos com elevada acurácia. No entanto, esta é verificada apenas se houver o genótipo real para avaliar a confiabilidade do genótipo imputado. Dessa maneira, os objetivos deste trabalho foram: (1) estudar a imputação de painéis comercial e customizados de baixa densidade para painéis de alta densidade (Illumina e Affymetrix), assim como para um painel combinado (Illumina + Affymetrix) para bovinos da raça Nelore, e estudar o desequilíbrio de ligação e conformação de blocos de haplótipos antes e após a imputação; (2) estudar estratégias para predição da acurácia de imputação, utilizando redes neurais artificiais e regressão linear múltipla; (3) estudar os segmentos de homozigose e, com isso, a endogamia presente em uma população de bovinos da raça Nelore, assim como identificar os genes presentes nos segmentos de homozigose mais frequentes na população. Os estudos de ROH foram realizados com utilização de informações de 34 touros de diferentes linhagens e suas progênies, totalizando 809 animais genotipados da raça Nelore com informação de 509.107 SNPs (Illumina). Para as análises de imputação e de predição da acurácia de imputação foram utilizados os mesmos animais, sendo que 93 destes também foram genotipados com o painel “Axion Genome-Wide BOS 1 Array Plate”. A partir dos resultados das análises de imputação demonstrou-se que o uso combinado de painéis pode ser uma alternativa para aumentar a densidade e o número de bloco de haplótipos, aumentando a probabilidade de obter um marcador próximo a um QTL de interesse. Além disso, essa estratégia indica que a escolha de SNPs em comum entre os painéis de alta densidade (Ilumina e Affymetrix) pode ser utilizada para customizar um painel de menor densidade, permitindo elevar a acurácia de imputação do painel da Illumina e Affymetrix. Na análise de predição da acurácia de imputação, a utilização de redes neurais artificiais foi mais eficiente comparada ao modelo de regressão linear múltipla, podendo ser utilizada com esta finalidade. A partir dos resultados das análises de ROH observou-se que a população encontra-se com baixo nível de endogamia, no entanto os reprodutores apresentaram maior valor de endogamia comparado a progênie, o qual somado a presença de segmentos de homozigose mais longos nestes animais podem indicar que tenha ocorrido intensa utilização de poucos reprodutores nas gerações mais recentes em algumas famílias. / Among all the information provided by methodologies that use single nucleotide polymorphism (SNPs), the runs of homozygosity (ROH) and linkage disequilibrium have been used for studies that explore genomic information in beef cattle population, as the genome-wide association, genomic selection, the structure of population and others. Nowadays, the imputation is used in these studies to reduce genomic costs and this also can be used combining genomic information from different panels. The animals used to be imputed should present genotypes inferred with high accuracy to allow the use imputed genotypes in other studies. However, the accuracy is verified only if there is a real genotype to evaluate the imputed genotype. Therefore, this study aimed: (1) Evaluate imputation of commercial and customized low density panels to high density panels (Illumina and Affymetrix), as well as to a combined panel (Illumina + Affymetrix) in Nelore beef cattle, and estimating linkage disequilibrium and haplotype blocks conformation to high density panels individually and after imputation; (2) Study a strategy to predict imputation accuracy using artificial neural network and linear regression; (3) Study runs of homozygosity and inbreeding in a populations from Nelore beef cattle, as well as identify genes present in ROH with high frequency in population. For ROH studies were used 34 bulls from different lines and the progeny, totalizing 809 Nelore animals genotyped with information of 509.107 SNPs (Illumina). The imputation analysis and imputation accuracy prediction used the same animals, wherein 93 were also genotyped with Axion Genome-Wide BOS 1 Array Plate. The imputation analysis demonstrates that the combined panels used from different panels can be considered due to increasing the density and number of haplotype blocks, increasing the probability to find a marker close to an important QTL. Furthermore, this strategy indicates that the choice for common SNPs between high-density panels Illumina and Affymetrix to customize a lower density panel can increase the imputation accuracy to Illumina and Affymetrix. The prediction of imputation accuracy analysis showed that the neural network is more efficient compared to linear regression, and could be used for this purpose. The results from ROH analysis showed low population inbreeding, however the sires presented higher inbreeding compared to progenies and longer runs of homozigosity, which suggest that has occurred intense use of few sires in recent generations in some families. / FAPESP: 2015/25096-6 e 2016/22940-3.
28

Caracterização da região Bru1 no genoma da cultivar RB867515 (Saccharum spp.) utilizando sequenciamento de nova geração / Characterization of Bru1 region of sugarcane cultivar RB867515 using next generation sequencing

Souza, Isabela Pavanelli de 25 September 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-18T14:12:04Z No. of bitstreams: 2 Dissertação - Isabela Pavanelli de Souza - 2014.pdf: 8334281 bytes, checksum: 3dab37e35c18875483625a1b3a46036d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-18T14:13:10Z (GMT) No. of bitstreams: 2 Dissertação - Isabela Pavanelli de Souza - 2014.pdf: 8334281 bytes, checksum: 3dab37e35c18875483625a1b3a46036d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-18T14:13:10Z (GMT). No. of bitstreams: 2 Dissertação - Isabela Pavanelli de Souza - 2014.pdf: 8334281 bytes, checksum: 3dab37e35c18875483625a1b3a46036d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-09-25 / Financiadora de Estudos e Projetos- Finep / Outro / Sugarcane is known as one of the most important crops of the word for its sub products utilization. Four countries, led by Brazil, supply the sugar international trade. Ethanol is other important sugarcane sub product, recognized as an alternative product to sugar, and had great demand in Brazilian trade, for its utilization as non-fossil fuel. The sugarcane genome is one of the most complex among crops, with 10 Gb. Its complete genome is not available, but the recent innovations in genomics tools open up new possibilities for the investigations about the sugarcane’s genome. We did a genome assembly and annotation of a Brazilian sugarcane cultivar (RB867515) genome region, correspondent to eight R570 homologous sequences already published. We use high qualities paired-ends libraries produced by Illumina HiSeq 2000 sequencing platform. The reads were aligned against eight R570 BACs (Bacterial Artificial Chromosome) sequences stored in NCBI using Bowtie2. We used MaSuRCA to assemble the aligned reads de novo, and the consensus sequences were obtained with SAMtools mpileup option. The transposable elements were identified using RepeatMasker and the gene regions were annotated with Blastx against the GenBank non-redundant protein database. After that, the consensus sequences were aligned with the matching reference (R570) using ClustalW in Mega software, to look for the percentage of mismatches and conserved sites between them. We obtained the number of scaffolds bigger than 1 kb ranging from 607 to 2,884, and the longest scaffold had near 21 kb. The consensus sequence length ranged from 81 to 142 kb, and the recovery rate relative to the reference ranged from 82% to 97%. The sequences amounted 1 Mb of RB867515 cultivar genome. We identified 5,145 repeated elements, which 4,662 were microsatellite and 460 were transposable elements, amounted 225 kb of repeated sequences. Among the mobile elements, the retrotransposons comprises 15% of nucleotide composition, ranging from 8% to 29% among BACs. The 134 genes identified on the eight BAC consensus sequences comprised a total of 243 kb, resulting in a density of one gene per 7.2 kb. The average number of genes per BAC was 16, with an average gene length of 1,841 bp. The percentage of mismatches between the RB867515 and R570 BACs ranged from 0.27% to 1.32%. The sugarcane BACs correspond to homeologous genomic regions, with this alignment we can suggest high divergence inside an homeologous group. / A cana-de-açúcar é reconhecida como uma das mais importante culturas do mundo, pela utilização dos seus subprodutos. O genoma da cana-de-açúcar é um dos mais complexos entre as plantas cultivadas, com aproximadamente 10 Gb. Seu genoma completo ainda não foi sequenciado, mas o surgimento e a popularização de novas ferramentas de análise genômica possibilitaram estudos refinados sobre essa cultura. Com o grande volume de informações que é possível gerar, a demanda atual é a produção ferramentas eficientes para o processamento dos dados. Foi realizado um assembly e anotação de uma região do genoma da cultivar RB867515 correspondente às sequências de 8 BACs da cultivar R570. As regiões correspondentes foram obtidas por alinhamento usando Bowtie2 com reads de bibliotecas paired-ends produzidos por sequenciador automático de nova geração e montados de novo utilizando MaSuRCA. Os scaffolds foram alinhados às sequência de referência usando BWA-SW, e as sequências consenso foram obtidas pela opção mplieup do SAMtools. Reads de cDNA de cinco tecidos vegetais, provenientes de 30 genótipos de cana-de-açúcar obtidos pela estratégia RNA-seq, foram mapeados nas sequências consenso a fim de identificar as regiões gênicas, que foram anotadas utilizando Blastx contra o banco de proteínas não redundante no GenBank. As regiões repetitivas foram determinadas pelo RepeatMasker e os microssatélites pelo IMEX. Para a comparação entre as sequências das duas cultivares, foi realizado uma alinhamento das sequências correspondentes nos dois genomas utilizando ClustalW no software Mega. O assembly das oito regiões, gerou de 607 à 2884 scaffolds maiores que 1 kb, com o maior scaffold chegando a 21 kb. As sequências consenso variam de 81 a 142 kb de tamanho, representando uma taxa de recuperação em relação à referência de 82% a 97%. O tamanho total das sequências montadas somou quase 1 Mb do genoma da cultivar de cana-deaçúcar. Em relação à anotação, foram identificados 5145 elementos genéticos repetitivos, em que 4662 são microssatélites e 460 são transposons, totalizando 225 kb em sequências repetidas ao longo dos BACs. Dentro do grupo dos elementos genéticos móveis os retrotransposons são maioria, com 15% da composição nucleotídica, variando de 8% a 29% entre os BACs. Foram identificados 134 genes nas oito sequências de cana-de-açúcar analisadas, totalizando 243 kb. O número de genes por BAC variou de 11 a 26, com uma média de 16 genes por BAC. Os genes encontrados apresentaram tamanho médio de 1841 pb, variando de 443 (BAC1) à 6316 pb (BAC3). A densidade de genes média foi de 1 gene por 7,2 kb. A porcentagem de mismatches entres as sequências dos BACs de RB867515 variou de 0,27% a 1,32%. Os BACs de cana-deaçúcar correspondem a regiões genômicas homeólogas, com o alinhamento realizado com as duas cultivares pode-se sugerir que existe alta divergência dentro do grupo de homeologia.
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Hippocampal Transcriptomic Profiles: Subfield Vulnerability to Age and Cognitive Impairment

Ianov, Lara, De Both, Matt, Chawla, Monica K., Rani, Asha, Kennedy, Andrew J., Piras, Ignazio, Day, Jeremy J., Siniard, Ashley, Kumar, Ashok, Sweatt, J. David, Barnes, Carol A., Huentelman, Matthew J., Foster, Thomas C. 08 December 2017 (has links)
The current study employed next-generation RNA sequencing to examine gene expression differences related to brain aging, cognitive decline, and hippocampal subfields. Young and aged rats were trained on a spatial episodic memory task. Hippocampal regions CA1, CA3, and the dentate gyrus were isolated. Poly-A mRNA was examined using two different sequencing platforms, Illumina, and Ion Proton. The Illumina platform was used to generate seed lists of genes that were statistically differentially expressed across regions, ages, or in association with cognitive function. The gene lists were then retested using the data from the Ion Proton platform. The results indicate hippocampal subfield differences in gene expression and point to regional differences in vulnerability to aging. Aging was associated with increased expression of immune response-related genes, particularly in the dentate gyrus. For the memory task, impaired performance of aged animals was linked to the regulation of Ca2+ and synaptic function in region CA1. Finally, we provide a transcriptomic characterization of the three subfields regardless of age or cognitive status, highlighting and confirming a correspondence between cytoarchitectural boundaries and molecular profiling.
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Fine-Grained Bacterial Compositional Analsysis of the Port Everglades Inlet (Broward County, FL) Microbiome using High Throughput DNA Sequencing

O'Connell, Lauren M 28 October 2015 (has links)
Port Everglades Inlet is one of the busiest ports in the country and is a point source of pollution to surrounding beaches and offshore corals from heavy boat traffic and urban runoff. Understanding fluctuations of bacterioplankton communities in major port inlets is important due to their impacts on surrounding marine environments. To understand annual microbial fluctuations, the 16s rRNA V4 hypervariable region was sequenced using Illumina high-throughput DNA sequencing technology. Surface samples were taken weekly for one year to generate baseline fluctuations in the microbial community. Total reads of 1.4 million were generated with a final count of 16,384 Operational Taxonomic Units. The dominant phyla were Proteobacteria, Cyanobacteria, Bacteroidetes, and Actinobacteria. Pathogenic genera were detected at low abundances during peak shipping and tourist months (November –April). Results indicate significant differences in alpha diversity when comparing microbial communities in August with other times. This was likely caused by low community richness and abundance, and below-average August rainfall levels. Differences in beta diversity were significant when comparing monthly and seasonal changes. Rainfall, temperature, and nutrient trends may have affected microbial composition, specifically during the dry season that was warmer and wetter than historical averages for 2013-2014. Increased nitrogen and phosphorous concentrations were observed in the dry season months of October, December, and January potentially creating optimal bacterial growth conditions. These results can be compared with historical and future data regarding inlet microbial communities to determine underlying baselines of bacterioplankton communities and monitor the health of marine and recreational environments they impact. This study represents the first to characterize at this scale and use Illumina MiSeq technology to analyze water samples from Port Everglades.

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