Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-04-06Bitstream added on 2014-06-13T20:53:58Z : No. of bitstreams: 1 spenassatto_c_me_botib.pdf: 1377275 bytes, checksum: 6cf6a389dd380de975e39f9fc9268330 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Aedes aegypti, culicídeo de hábitos diurnos, é originário do continente africano e está globalmente distribuído pelos trópicos em associação com as populações humanas. É considerado de grande importância epidemiológica por ser o principal vetor dos quatro sorotipos do vírus da dengue e da febre amarela. Uma das primeiras detecções da presença do mosquito no Estado de São Paulo aconteceu na década de 80 na cidade de Santos. Atualmente não há disponível nenhuma vacina ou medicamento eficiente contra a dengue, assim o controle da doença está restrito ao controle do vetor. Uma das alternativas de controle e entendimento das relações vetor-patógeno-homem se baseiam no desenvolvimento de ferramentas moleculares que utilizam técnicas baseadas em PCR, as quais têm possibilitado o estudo genético das populações do Ae. aegypti. Em tais estudos, vários marcadores foram envolvidos, tais como os SNPs (Single Nucleotide Polymorphisms) e marcadores mitocondriais. Nós desenvolvemos ensaios utilizando metodologia TaqMan® para o estudo genético populacional de duas populações do mosquito Aedes aegypti de cidades portuárias do Estado de São Paulo, utilizando nove marcadores SNPs. Verificamos que esta metodologia é reprodutível, rápida, de baixo custo e eficiente para estudos em larga escala. Pela análise AMOVA encontramos uma baixa, mas significativa diferenciação genética entre as populações do estudo (FST = 0,0324; P < 0,01), e uma alta taxa de migrantes por geração (8,72 entre as populações 2007 e 5,39 entre as populações 2008), indicando fluxo gênico entre as populações. A análise implementada no software Structure 2.3.1, evidenciou a existência de três clusters baseados em semelhanças genotípicas, distribuídos em dois grupos, confirmando uma moderada estruturação populacional. Verificamos através da análise de fragmentos... / Aedes aegypti, is a diurnal mosquito, originated from the African continent and is globally distributed through the tropics in association with human populations. It is considered of great epidemiological importance for being the main vector of the four serotypes of Dengue and Yellow Fever. One of the first detections of the presence of the mosquito in the State of São Paulo happened in the 80's, in the city of Santos. Currently there is no available vaccine or effective medicine against dengue fever, and disease control is restricted to vector control. An alternative to control and understanding of vectorpathogen- man relationships are based on the development of molecular tools that use PCR-based techniques, which have enabled the genetic study of populations of Ae. aegypti. In such studies, several markers were involved, such as SNPs (Single Nucleotide Polymorphisms) and mitochondrial ones. We have developed assays using TaqMan® methodology for population genetic studies of two populations of Aedes aegypti from the port cities of São Paulo, using nine SNPs markers. We found that this methodology is reproducible, fast, inexpensive and efficient for large-scale studies. AMOVA analysis found a low but significant genetic differentiation between the studied populations (FST = 0.0324, P <0.01), and a high rate of migrants per generation (8.72 among populations in 2007 and 5.39 among populations in 2008), indicating gene flow between populations. The analysis implemented in software Structure 2.3.1, revealed the existence of three clusters based on genotypic similarities, divided into two groups, confirming a moderate population structure. We verified through the analysis of the mitochondrial gene fragments NADH dehydrogenase subunit 4 (ND4) a high genetic differentiation between the two study populations (FST = 0.18034, P <0.01), and a rate of migrants per generation considered high... (Complete abstract click electronic access below)

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Currently, the most widely used in vivo mutation monitoring system in humans is the hypoxanthine-guanine phosphoribosyltransferase (hprt) T-cell clonal assay. This dissertation examines the current state of the hprt monitoring system and the usefulness of hprt mutational spectra in revealing environmental exposures. The nature of spontaneous mutational spectra recovered through the implementation of this system is detailed. An examination of hprt mutation frequencies obtained from a set of monozygotic twins revealed a striking influence of genetic factors. As age increases, the influence of genetic factors controlling mutation frequency appears to be modified by environmental factors. Mutational spectra obtained from Russian individuals living in Moscow were distinct from the spectrum of mutation observed in age-matched Western controls. Analysis of the relationship between mutation frequency and subject age clearly demonstrated the lack of any relationship for subjects after the age of 55. This finding contradicts many previously published reports on the relationship between mutation frequency and age. Finally, the influence of tobacco smoking on mutational frequency is clear, however, no change in the mutational spectrum of smokers was revealed. Changes in mutational spectrum are analyzed in the context of the T-cell biology and reveal that the dynamics of this tissue are likely responsible for the observations made in this dissertation. Although the hprt gene is a highly robust and suitable target for the analysis of mutation, the target has not yet been saturated, and new single base-pair substitutions are still being characterized. The data clearly suggest that the T-cell clonal assay in its current state may not be a suitable mutational monitoring system for human populations. This dissertation concludes that new mutational assays need to be developed for monitoring mutations in human populations. / Graduate

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Parametric excitation and dispersal are added to discrete-time population models. Discrete-time models for growth with dispersal share many of the attributes of reaction-diffusion equations. At the same time, these models readily exhibit period doubling and chaos. Large parametric excitation (seasonality) is inevitably destabilizing, but mild seasonality may have a pronounced stabilizing effect. Seasonality also allows for the coexistence of alternative stable states (equilibria, cycles, chaos). Many examples are presented.

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Genetic variation contains detailed and quantitative evidence about the history of populations. The historical traces of demographic growth and contraction, as well as the history of human disease, have left traces on the patterns of modern variation and can be studied by sampling present-day populations. However, the data sets that are necessary in order to take full advantage of this living archaeological record have not been available until recently. The quality and quantity of data have increased dramatically during the past decade because of the identification of polymorphisms, including SNPs and microsatellites, that are much more amenable to mathematical modeling and efficient genotyping than earlier marker systems. The research in this thesis has been carried out in response to the need to provide new methods of analysis to match the new types of data. Chapter 1 describes multilocus tests of demographic history and their application to real data. Chapter 2 describes how the pattern of linkage disequilibrium around a disease-predisposing mutation can be used to estimate the date of a mutation that is, the age of the most recent common ancestor of a set of modern samples. Finally, Chapter 3 draws several direct connections between human evolutionary history and medical genetics.

The structuring of Atlantic salmon (Salmo salar L.) into discrete, genetically differentiated populations both within and between river catchments is well documented. The utilisation of this knowledge has proved valuable in a variety of evolutionary, ecological, managerial and conservation contexts. In this thesis, the genetic structuring of Atlantic salmon populations in northwest Europe was assessed in two catchments of very different sizes, using a range of molecular and associated population genetic methods; findings from the catchment level research are set in context by a broader phylogeographic study of post-glacial colonisation of the region. A regional study into the glacial origins and post-glacial colonisation routes of Atlantic salmon in northwest Europe was explored by analysing a pre-existing microsatellite dataset and supplementing it with haplotype data from mtDNA PCR-RFLP analysis of the same samples (N=702). Evidence from allele permutation tests undertaken on the microsatellite data alongside mtDNA haplotype frequencies suggested that there was a cryptic northern refuge in northwest France, with colonisation of the British Isles and Ireland occurring from this and the long-known Iberian Peninsula refuge. Catchment level studies were undertaken on the river Dart and river Tweed, involving 1151 fish being genotyped with 14 microsatellite loci with a subset of 211 fish being genotyped by mtDNA PCR-RFLP. In both catchments, populations were found to be weakly differentiated genetically, and were most consistent with the meta-population theory of evolution. Similarly, individual spatial autocorrelation analysis indicated that each major tributary within the catchments could be considered as a distinct management or conservation unit. In the Tweed dataset, however, limitations in the sample coverage across the catchment reduced the robustness of some findings. Historical stocking of the river Dart with fish from Scotland and Iceland is well-documented. The long-term implications of these activities on contemporary Dart populations were assessed by genotyping 177 fish from the donor populations using scale samples taken in the 1960s and comparing them to contemporary Dart populations by undertaking admixture analysis. Overall, admixture between the donor and recipient populations was low and appeared to reflect natural underlying levels of genetic relationships. However, increased admixture of donor stocks with one extant Dart population was apparent, indicating some potentially long-term localised success of the stocked fish through hybridisation with the native populations; nevertheless, with the population continuing to decline, this should not be viewed as a successful supplementation programme. Two tributaries on the river Tweed, the Gala and Leader, were inaccessible to salmon for long periods due to the construction of barriers to migration. On both tributaries, fish passes were installed in the 1940s and re-colonisation of the tributaries was possible. Assignment analysis was undertaken and indicated that, contrary to findings for between catchment studies, salmon straying from the most proximate tributaries (i.e. the Ettrick and Caddon) did not appear to be the principal colonisers of the current Gala and Leader populations. Rather, the highest proportion of Gala samples assigned to the Teviot (42%), with the Leader populations assigning to many tributaries across the catchment (Ettrick 28%; Upper 21%; Teviot 19%). However, given the relatively weak differentiation of the baseline samples and limitations inherent in the dataset, the correct self-assignment of baseline samples was very low (average 26%; range 0-47%), hence interpretation must be undertaken with caution. Nevertheless, the findings suggest that the Gala population may have reached a temporally stable state in the 60 years since it has been accessible to salmon. Whilst the relatively small scale of these studies is acknowledged, the application of the findings in management and conservation of the species are discussed in a wider context. These studies would support the following recommendations: to include information on the historic (refugial) origin of contemporary populations in regional management strategies; to treat each major tributary as a distinct unit as an appropriate scale for catchment level management; and, with stocking and supplementation programmes appearing to have no significant long-term success, coupled with the relative speed with which extirpated tributaries appear to be naturally re-colonised, the use of stocking and supplementation programmes should be discouraged.