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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.
11

Utility of the Cytochrome Oxidase I gene (COI) for Species Identification and Phylogeographic Analysis in Black Flies (Diptera: Simuliidae)

Rivera Castillo, Julio Martin 26 February 2009 (has links)
A short sequence of ca. 658-bp of the mitochondrial gene COI was used to investigate its utility as a DNA barcode in the medically important Simuliidae or black flies. Sixty-five species and species complexes were tested. Results indicate that the barcoding gene discriminated among morphologically distinct species with nearly 100% of efficacy and proved useful for revealing cryptic diversity. The DNA barcoding gene was also tested for revealing phylogeographic patterns in the western cordilleran Prosimulium travisi and the Prosimulium neomacropyga species-group. Phylogeographic analyses on these species revealed areas that acted as glacial refugia, postglacial history, cryptic speciation episodes and timing of the events that lead to their present-day distribution. The results obtained concur with other phylogeographic studies on similarly-distributed cordilleran organisms. In conclusion, the barcoding gene not only resulted useful for species discrimination in black flies but also for studies at the population level, providing value-added to this molecular marker.
12

Utility of the Cytochrome Oxidase I gene (COI) for Species Identification and Phylogeographic Analysis in Black Flies (Diptera: Simuliidae)

Rivera Castillo, Julio Martin 26 February 2009 (has links)
A short sequence of ca. 658-bp of the mitochondrial gene COI was used to investigate its utility as a DNA barcode in the medically important Simuliidae or black flies. Sixty-five species and species complexes were tested. Results indicate that the barcoding gene discriminated among morphologically distinct species with nearly 100% of efficacy and proved useful for revealing cryptic diversity. The DNA barcoding gene was also tested for revealing phylogeographic patterns in the western cordilleran Prosimulium travisi and the Prosimulium neomacropyga species-group. Phylogeographic analyses on these species revealed areas that acted as glacial refugia, postglacial history, cryptic speciation episodes and timing of the events that lead to their present-day distribution. The results obtained concur with other phylogeographic studies on similarly-distributed cordilleran organisms. In conclusion, the barcoding gene not only resulted useful for species discrimination in black flies but also for studies at the population level, providing value-added to this molecular marker.
13

Species Richness and Genome Size Diversity in Hymenoptera with Different Developmental Strategies: A DNA Barcoding Enabled Study

Lima, João 11 September 2012 (has links)
A species threshold was used to assign unidentified Hymenoptera into DNA barcode Operational Taxa (DbOT) for both an assessment of species richness in rose gall communities and as part of a broad scale survey of genome size diversity. The species threshold of 2.2% was calculated from minimum interspecific divergence of DNA barcode (COI, mtDNA) and internal transcribed spacer region 1 (ITS1, rDNA) sequences from both identified and unidentified Hymenoptera associated with rose galls induced by Diplolepis (Cynipidae). Analysis of both DNA barcodes and ITS1 sequences suggested that several described species of Diplolepis (Cynipidae), Periclistus (Cynipidae), and Torymus (Torymidae) require re-examination to define species boundaries. It was also determined that the total number of DbOTs is higher than previous estimates of species richness of Hymenoptera associated with rose galls induced by Diplolepis. Additionally, genome size estimations were determined for 51 DbOTs from all eight families of Hymenoptera associated with rose galls induced by Diplolepis, five of which did not have any previous genome size estimates. A subsequent large-scale survey of Hymenoptera enabled by the use of the DbOT approach produced genome size estimations for 309 DbOTs from 36 families in 13 superfamilies. It was shown that Hymenoptera do not have smaller genome sizes than other holometabolous orders, and that a parasitoid lifestyle does not appear to constrain genome size. The suggested positive relationship between genome size and development time was investigated by comparing mean genome size of taxa with known or apparent differences in development rate. It was concluded that statistical comparisons between taxa that are grouped in broad categories would be unlikely to detect significant differences in mean genome size because the range of biological features within such categories is highly variable. However, comparisons between interacting groups with narrowly defined development strategies determined that mean genome size was statistically smaller in taxa that obtained resources within a narrow window of opportunity. This result suggests that rapid development in relation to competitors may be important in species of Hymenoptera with higher mortality risk.
14

Community phylogenetics: methodological approaches and patterns in subarctic freshwater insect systems

Boyle, Elizabeth 03 October 2012 (has links)
I aimed to expand our understanding of community assembly and species co-existence by examining the implications of phylogenetic robustness on metrics describing phylogenetic community structure, as well as the phylogenetic patterns of co-occurring insect species in Churchill, MB. Using a variety of tree reconstruction methods, I found that cytochrome c oxidase subunit I (COI) was able to accurately estimate phylogenetic community structure metrics calculated from a multi-gene phylogeny when using more biologically realistic approaches. This included incorporating known phylogenetic relationships among families, and methods that employ best-fit models of molecular evolution (i.e. Bayesian inference). My second study examined the phylogenetic community patterns of freshwater insects. Overall communities were phylogenetically clustered suggesting environmental filtering, but community structure varied with time, habitat, taxonomic group, and water chemistry (particularly pH and turbidity). My thesis has suggested more robust techniques for calculating phylogenetic community structure, and described patterns of phylogenetic community composition in subarctic freshwater insects. / Natural Sciences and Engineering Research Council of Canada (NSERC), International Barcode of Life (iBOL), Genome Canada, Ontario Genomics Institute, Canadian Foundation for Innovation, Ontario Ministry of Research and Innovation, Churchill Northern Studies Centre, and Aboriginal Affairs and Northern Development Canada.
15

Phylogenetics and molecular identification of the Ochlerotatus communis and Oc. punctor complexes (Diptera: Culicidae)

Hosseinzadeh Namin, Hooman 10 September 2013 (has links)
Accurate identification of pathogens and vectors is essential in epidemiological studies of mosquito-borne pathogens. However, the members of the communis and punctor complexes are difficult to distinguish because they are highly cryptic species, with little to no species-specific morphological characters. The objective of this thesis is to develop molecular tools, including RFLP and DNA barcoding using cytochrome oxidase I (COI), internal transcribed spacer 2 (ITS2) and the intron of ribosomal protein S12 (RPS12) to facilitate identification of the members of these two complexes in Manitoba. A distinct interspecific distance for COI was found between the members of the communis complex included here, and diagnostic RFLP profiles were developed for Oc. communis and Oc. churchillensis. Relatively low average interspecific genetic distances using COI, ITS2 and RPS12 were observed between the members of the punctor complex, indicates no discernable boundaries between these species based on DNA barcoding.
16

Phylogenetics and molecular identification of the Ochlerotatus communis and Oc. punctor complexes (Diptera: Culicidae)

Hosseinzadeh Namin, Hooman 10 September 2013 (has links)
Accurate identification of pathogens and vectors is essential in epidemiological studies of mosquito-borne pathogens. However, the members of the communis and punctor complexes are difficult to distinguish because they are highly cryptic species, with little to no species-specific morphological characters. The objective of this thesis is to develop molecular tools, including RFLP and DNA barcoding using cytochrome oxidase I (COI), internal transcribed spacer 2 (ITS2) and the intron of ribosomal protein S12 (RPS12) to facilitate identification of the members of these two complexes in Manitoba. A distinct interspecific distance for COI was found between the members of the communis complex included here, and diagnostic RFLP profiles were developed for Oc. communis and Oc. churchillensis. Relatively low average interspecific genetic distances using COI, ITS2 and RPS12 were observed between the members of the punctor complex, indicates no discernable boundaries between these species based on DNA barcoding.
17

Aplikace molekulárních metod na identifikaci nekrofágních zástupců řádu Diptera, typických pro Jihomoravský kraj

Mifková, Tamara January 2016 (has links)
Necrophagous insects plays an important role, especially in forensic practice, especially in determining the time of death. This work was aimed to monitor necrophagous species of the Diptera order in selected localities of South Moravian Region - Rakvice and Sokolnice. Furthermore, these necrophagous species were identified with anatomical-morphological and molecular genetic methods, which have been compared to each other. For this purpose it was necessary to isolate a DNA segment and amplify cytochrome oxidase I (COI) gene by the PCR method and with further processing to obtain the sequence of selected individuals from the mitochondrial genome. The results of the experiment more coincided with morphological identification database BOLD outputs than with outputs from the BLAST database. Anatomical and morphological identification cannot always accurately determine the genus and species necrophags, the assesment is not dependent not only on the development stage of the insect and its condition, but also on the expertise of the determinator. Most accurater results are achieved with use the combination of anatomical and morphological and molecular-genetic methods of determination, which is confirmed by the results of this thesis.
18

Druhová identifikace u Lepidopter pomocí jaderných genů CAD a EF-1?

Wijacki, Jan January 2016 (has links)
Biodiversity is an important element to conserve life on earth. We can divide it into three main categories: gene diversity, species diversity and the complex ecosystem diversity. In the world there are an estimated 10 million plant and animal species, but only about 1.5 million are described. DNA barcoding is a molecular method which helps to identify species by comparing the sequences of mitochondrial or nuclear genes. Within lime hawk-moth (Mimas tiliae) species could exist four different subspecies. The aim of this thesis is to verify usability of the nuclear genes CAD and EF-1a by the DNA barcoding method and to compare these results with the analysis of mitochondrial COI gene.
19

Biodiversidade dos Loricariidae (Teleostei Siluriformes) das bacias costeiras do sudeste e sul do Brasil /

Souza, Camila da Silva de January 2017 (has links)
Orientador: Claudio de Oliveira / Abstract: The coastal drainages of Southern and Southeastern Brazil are part of the Eastern basin, currently composed by different drainages. The large distribution area and variety of habitats along these drainages have a direct influence on the species diversity and their high level of endemism. However, this region has been suffered intense exploration and loss of habitat due to anthropic actions. The present study aimed to identify Operational Taxonomic Units (OTUs) of the Loricariidae and to delimit ecoregions through their distribution patterns. A total of 499 partial sequences of the mitochondrial COI gene were analyzed, belonging to 47 Loricariidae species. 58 OTUs were delimited along 31 drainages of Southeastern and Southern coastal revealing a previously unrecognized genetic diversity for some groups. The 31 drainages based on Parsimony Analysis of Endemicity (PAE), were divided in five groups, characterizing areas that are favorable to the delimitation of ecoregions. The Jacuí, Ribeira de Iguape and Paraíba do Sul rivers presented fairly exclusive faunas in relation to morphological and genetic patterns, being essential for preservation. The stream capture and paleoclimatic events are largely responsible for the distribution of the Loricariidae along the drainages. / Resumo: Os rios costeiros da região Sul e Sudeste do Brasil fazem parte do complexo hidrográfico da bacia do Leste, que abriga diferentes drenagens isoladas atualmente, entre as quais destacamse, na região Sul e Sudeste as do Paraíba do Sul, Ribeira de Iguape, Itajaí e Jacuí. A grande área de distribuição e variedade de habitats ao longo dessas drenagens têm influência direta na diversidade de espécies e no seu alto nível de endemismo. No entanto, essa região vem sofrendo intensa exploração e perda de habitas por ações antrópicas. Trabalhos de zoneamento dessa região vêm sendo realizados com o intuito de fornecer melhores dados para a sua preservação. Nesse sentido, o presente trabalho teve como objetivo identificar unidades taxonômicas operacionais (OTUs) da família Loricariidae e delimitar ecorregiões através de seus padrões de distribuição. Foram analisadas 499 sequências parciais do gene mitocondrial Citocromo c Oxidase subunidade I (COI), representantes de 47 espécies de Loricariidae e encontradas 58 OTUs distribuídas ao longo de 31 drenagens da região costeira Sul e Sudeste do Brasil, revelando uma diversidade genética antes não reconhecida para alguns grupos. As 31 drenagens, com base na Análise de Parcimônia de Endemismo (PAE), foram divididas em cinco grupos, caracterizando áreas propícias à delimitação de ecorregiões. As drenagens Jacuí, Ribeira de Iguape e Paraíba do Sul, apresentaram faunas bastante exclusivas em relação a padrões morfológicos e genéticos, sendo imprescin... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
20

DISCRIMINAÇÃO GENÉTICA DE ESPÉCIES DE PFAFFIA SPP. (GINSENG BRASILEIRO) USANDO CÓDIGO DE BARRAS DE DNA

FIALHO, V. L. S. 09 March 2017 (has links)
Made available in DSpace on 2018-08-01T20:28:07Z (GMT). No. of bitstreams: 1 tese_11108_Dissertação_Verônica Luiza S. Fialho.pdf: 825449 bytes, checksum: 700df7d34ebe1579f26a45eb08933658 (MD5) Previous issue date: 2017-03-09 / Plantas das espécies Pfaffia spp. são amplamente utilizadas em território nacional e são popularmente conhecidas como Ginseng-brasileiro. As espécies mais conhecidas são a Pfaffia glomeratae a Pfaffia paniculata. Há indicações de uso como tônico e revigorante geral, no tratamento de fadiga física, esgotamento mental, falta de memória, como auxiliar no tratamento de distúrbios circulatórios, dentre outros. Embora as duas espécies sejam utilizadas com os mesmos propósitos, deve-se considerar que a diferença química entre elas pode interferir nos espectros de ações farmacológicas e toxicológicas. A identificação morfológica das raízes é tarefa difícil sobretudo devido a sua forma de comercialização. Por isso, faz-se necessário o desenvolvimento de novas metodologias de identificação das espécies comercializadas. O objetivo principal deste trabalho foi identificar, em nível de espécie, amostras de Ginseng-brasileiro vendidos no mercado brasileiro, utilizando, para isso, o código de barras de DNA (DNA barcode). O DNA de 60 amostras comerciais foi extraído e os genes matK e rbcL foram amplificados por PCR e sequenciados. Além disso, amostras referência, morfologicamente identificadas, das duas espécies foram utilizadas para comparação e submetidas ao mesmo protocolo. Posteriormente, as amostras foram confrontadas com amostras referências e com o banco de dados BOLD (Barcode of Life Data Systems). Dentre as amostras referências, 90% amplificaram, tanto para matK quanto para rbcL. As amostras comerciais obtiveram taxa de amplificação de 95% para ambos os genes. Todas amostras foram sequenciadas. Encontrou-se uma diferença interespecífica entre P. glomerata e P. paniculata de 1,92% para matK e 1,90% para rbcL. Não foi encontrada variação intraespecífica. Das 58 amostras avaliadas, 67,24% foram identificadas, sendo 61,54% P. glomerata e 38,46% P. paniculata. O restante, 32,76% não foram identificadas conforme o rótulo, caracterizando adulteração. Desses, 22,41% não foram identificadas e 10,34% apresentaram substituição de espécies. O método de identificação por DNA bacode possibilitou a identificação, em nível de espécie, das amostras comercializadas como Ginseng brasileiro obtidas do mercado brasileiro, como P. glomerata e P. paniculata.

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