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Estudos genético-moleculares em Giardia duodenalis : caracterização da diversidade genética e análises populacionais em amostras clínicas e ambientais na região metropolitana de Campinas, São Paulo, Brasil = Genetic and molecular studies in Giardia duodenalis: molecular characterization of genetic diversity and population genetic analysis in clinical and environmental samples in the metropolitan region of Campinas, São Paulo, Brazil; Genetic and molecular studies in Giardia duodenalis : molecular characterization of genetic diversity and population genetic analysis in clinical and environmental samples in the metropolitan region of Campinas, São Paulo, Brazil

Mauricio Durigan
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/02/2015 PT
Relevância na Pesquisa
56.06%
Giardia duodenalis é um protozoário flagelado que parasita o homem e diversos animais domésticos e selvagens. Este parasito causa a doença giardiose que é uma das mais prevalentes doenças parasitárias de veiculação hídrica do mundo, responsável por aproximadamente 280 milhões de casos anualmente. Existe uma considerável variabilidade genética em G. duodenalis, de modo que seus isolados foram divididos em oito grupos genéticos (A-H), dois dos quais (A e B) são encontrados tanto em humanos quanto em animais. Os demais grupos (C-H) parasitam outros animais e apresentam maior especificidade a determinados hospedeiros não humanos. A contaminação ambiental por Giardia tem sido amplamente descrita embora esses estudos, em sua maioria, são realizados no nível de identificação de espécie. Há falta de estudos que correlacionam a contaminação ambiental e infecções clínicas na mesma região. O presente trabalho teve como objetivo principal contribuir para o conhecimento da diversidade genética da espécie Giardia duodenalis. Primeiramente, foi realizada a genotipagem multilocos dos principais grupos genéticos de G. duodenalis na região metropolitana de Campinas. Foram encontrados grupos genéticos associados principalmente a infecções humanas bem como isolados com potencial zoonótico em amostras ambientais e obtidas de outros animais. Foi encontrado um alto percentual (25%) de amostras com grupos genéticos mistos e um elevado número de haplótipos distintos...

Some Consequences of Demographic Stochasticity in Population Genetics

Parsons, Todd L.; Quince, Christopher; Plotkin, Joshua B.
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /08/2010 EN
Relevância na Pesquisa
56.09%
Much of population genetics is based on the diffusion limit of the Wright–Fisher model, which assumes a fixed population size. This assumption is violated in most natural populations, particularly for microbes. Here we study a more realistic model that decouples birth and death events and allows for a stochastically varying population size. Under this model, classical quantities such as the probability of and time before fixation of a mutant allele can differ dramatically from their Wright–Fisher expectations. Moreover, inferences about natural selection based on Wright–Fisher assumptions can yield erroneous and even contradictory conclusions: at small population densities one allele will appear superior, whereas at large densities the other allele will dominate. Consequently, competition assays in laboratory conditions may not reflect the outcome of long-term evolution in the field. These results highlight the importance of incorporating demographic stochasticity into basic models of population genetics.

James F. Crow and the Stochastic Theory of Population Genetics

Ewens, Warren J.
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /02/2012 EN
Relevância na Pesquisa
56.02%
Research in population genetics theory has two main strands. The first is deterministic theory, where random changes in allelic frequencies are ignored and attention focuses on the evolutionary effects of selection and mutation. The second strand, stochastic theory, takes account of these random changes and thus is more complete than deterministic theory. This essay is one in the series of Perspectives and Reviews honoring James F. Crow on the occasion of his 95th birthday. It concerns his contributions to, and involvement with, the stochastic theory of evolutionary population genetics.

On the inclusion of self regulating branching processes in the working paradigm of evolutionary and population genetics

Mode, Charles J.; Sleeman, Candace K.; Raj, Towfique
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 19/02/2013 EN
Relevância na Pesquisa
56.14%
The principal goal of this methodological paper is to suggest to a general audience in the genetics community that the consideration of recent developments of self regulating branching processes may lead to the possibility of including this class of stochastic processes as part of working paradigm of evolutionary and population genetics. This class of branching processes is self regulating in the sense that an evolving population will grow only to a total population size that can be sustained by the environment. From the mathematical point of view the class processes under consideration belongs to a subfield of probability and statistics sometimes referred to as computational applied probability and stochastic processes. Computer intensive methods based on Monte Carlo simulation procedures have been used to empirically work out the predictions of a formulation by assigning numerical values to some point in the parameter space and computing replications of realizations of the process over thousands of generations of evolution. Statistical methods are then used on such samples of simulated data to produce informative summarizations of the data that provide insights into the evolutionary implications of computer experiments. Briefly, it is also possible to embed deterministic non-linear difference equations in the stochastic process by using a statistical procedure to estimate the sample functions of the process...

A Quantitative Test of Population Genetics Using Spatio-Genetic Patterns in Bacterial Colonies

Korolev, Kirill; Xavier, Joao; Foster, Kevin; Nelson, David R.
Fonte: University of Chicago Press Publicador: University of Chicago Press
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
66.12%
It is widely accepted that population genetics theory is the cornerstone of evolutionary analyses. Empirical tests of the theory, however, are challenging because of the complex relationships between space, dispersal, and evolution. Critically, we lack quantitative validation of the spatial models of population genetics. Here we combine analytics, on and off-lattice simulations, and experiments with bacteria to perform quantitative tests of the theory. We study two bacterial species, the gut microbe Escherichia coli and the opportunistic pathogen Pseudomonas aeruginosa, and show that spatio-genetic patterns in colony biofilms of both species are accurately described by an extension of the one-dimensional stepping-stone model. We use one empirical measure, genetic diversity at the colony periphery, to parameterize our models and show that we can then accurately predict another key variable: the degree of short-range cell migration along an edge. Moreover, the model allows us to estimate other key parameters including effective population size (density) at the expansion frontier. While our experimental system is a simplification of natural microbial community, we argue it is a proof of principle that the spatial models of population genetics can quantitatively capture organismal evolution.; Physics

Mitochondrial genomics and northwestern Atlantic population genetics of marine annelids

Jennings, Robert M. (Robert Michael)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 151 p.
ENG
Relevância na Pesquisa
66.13%
The overarching goal of this thesis was to investigate marine benthic invertebrate phylogenetics and population genetics, focused on the phylum Annelida. Recent expansions of molecular methods and the increasing diversity of available markers have allowed more complex and fine-scale questions to be asked at a variety of taxonomic levels. At the phylogenetic level, whole mitochondrial genome sequencing of two polychaetes (the deep-sea tubeworm Riftia pachyptila and the intertidal bamboo worm Clymenella torquata) supports the placement of leeches and oligochaetes within the polychaete radiation, in keeping with molecular evidence and morphological reinvestigations. This re-interpretation, first proposed by others, synonomizes "Annelida" and "Polychaeta", and lends further support to the inclusion of echiurids, siboglinids (previously called vestimentiferans) within annelids, and sipunculans as close allies. The complete mt-genome of C. torquata was then rapidly screened to obtain markers useful in short timescale population genetics.; (cont.) Two quickly evolving mitochondrial markers were sequenced from ten populations of C. torquata from the Bay of Fundy to New Jersey to investigate previous hypotheses that the Cape Cod, MA peninsula is a barrier to gene flow in the northwest Atlantic. A barrier to gene flow was found...

Population genetics and phylogeography of the largest wild cat in the americas: an analysis of the jaguar by means of microsatellites and mitochondrial gene sequences; Molecular Population Genetics, Evolutionary Biology and Biological Conservation of Neotropical Carnivores

Ruiz-Garcia, Manuel; Vásquez, Catalina; Murillo, Andrea; Pinedo Castro, Myreya; Alvarez, Diana
Fonte: Nova Science Pub Inc Publicador: Nova Science Pub Inc
Formato: 1-720
Relevância na Pesquisa
56.03%
A total of 250 jaguars directly sampled in the wild (Guatemala, Costa Rica, Colombia, Venezuela, French Guiana, Peru, Bolivia and central and western Brazilian Amazon) were analyzed for 12 DNA microsatellite loci and for three mitochondrial genes (NADH5, 16S rRNA and ATP8). The main results were as follows: 1- The levels of gene diversity were very high for microsatellites as well as for mt markers. These levels were higher than those obtained in other studies by Eizirik’s team. Explanations of why this occurred are herein discussed. 2- The highest gene diversity levels were found for the western Amazon areas for microsatellites as well as mt markers, with lower gene diversity levels for areas far as away as central and eastern Brazil and Central America. 3- The levels of genetic heterogeneity were small for the samples classified by morphological subspecies, by countries and by considering the Amazon River as a barrier. Therefore, there is no clear evidence of the existence of “real” subspecies in the jaguars, especially, for the forms of South America. It was also clear that the Amazon River was not a geographical barrier for this large species, disagreeing with the claims of Eizirik et al., (2001). The levels of genetic heterogeneity by country were slightly higher than by subspecies. This could have interesting repercussions in the conservation politics of each Neotropical nation where jaguars live. Several AMOVAs showed that the majority of gene diversity was placed in individuals and that no other upper hierarchical clusters have significant importance. The theoretical gene flow estimates were very high for microsatellites as well as mt markers. However...

Molecular Population Genetics, Evolutionary Biology and Biological Conservation of Neotropical Carnivores; Molecular Population Genetics, Evolutionary Biology and Biological Conservation of Neotropical Carnivores

Ruiz-Garcia, Manuel; Pinedo Castro, Myreya
Fonte: Nova Science Pub Inc Publicador: Nova Science Pub Inc
Formato: 1-720
Relevância na Pesquisa
66.14%
A total of 44 wild jaguarundis were sampled throughout Mexico, Guatemala, Costa Rica, Colombia, Venezuela, Ecuador, Peru, Bolivia and Brazil and sequenced for three mitochondrial genes (ATP8, 16S rRNA, NADH5). This is the first molecular population genetics and phylogenetic study of this species and the most relevant results were as follows: 1- The gene diversity levels for the jaguarundi at the three mitochondrial genes sequenced were very elevated as it was found for other Neotropical wild cats such as the jaguar, ocelot, margay and the Pampas cat; 2- The levels of gene heterogeneity among putative subspecies or among countries was extremely small, although this species has a broad distribution from southern USA to Argentina; 3- Additionally, the phylogenetics trees (genetic distances, maximum likelihood, maximum parsimony and Bayesian) showed that no molecular subspecies were defined in contradiction with the morphological classifications of Allen (1919), Cabrera (1957) and de Oliveira (1998); 4- Bayesian and network procedures showed that the first haplotype divergence process in the jaguarundi began around 2.0-1.6 MYA, with a second haplotype divergence event around 1.1-0.8 MYA, followed by other haplotype splits around 0.75-0.5 MYA...

Population Genetics and Phylogeographic Analyses of the Jaguarundi (Puma yagouaroundi) by Means of Three Mitochondrial Markers: The First Molecular Population Study of This Species.; Molecular population genetics, phylogenetics, evolutionary biology and conservation of the neotropical carnivores

Ruiz-García, Manuel; Pinedo-Castro, Myreya
Fonte: Nova Science Publishers, Inc. Publicador: Nova Science Publishers, Inc.
Formato: 245–288
Relevância na Pesquisa
66.11%
A total of 44 wild jaguarundis were sampled throughout Mexico, Guatemala, Costa Rica, Colombia, Venezuela, Ecuador, Peru, Bolivia and Brazil and sequenced for three mitochondrial genes (ATP8, 16S rRNA, NADH5). This is the first molecular population genetics and phylogenetic study of this species and the most relevant results were as follows: 1- The gene diversity levels for the jaguarundi at the three mitochondrial genes sequenced were very elevated as it was found for other Neotropical wild cats such as the jaguar, ocelot, margay and the Pampas cat; 2 - The levels of gene heterogeneity among putative subspecies or among countries was extremely small, although this species has a broad distribution from southern USA to Argentina; 3- Additionally, the phylogenetics trees (genetic distances, maximum likelihood, maximum parsi mony and Bayesian) showed that no molecular subspecies were defined in contradiction with the morphological classifications of Allen (1919), Cabrera (1957) and de Oliveira (1998); 4-Bayesian and network procedures showed that the first haplotype divergence process in the jaguarundi began around 2.0-1.6 MYA, with a second haplotype divergence event around 1.1-0.8 MYA...

Population Genetics and Phylogeography of the largest wild cat in the Americas: An analysis of the jaguar by means of microsatellites and mitochondrial gene sequences; Molecular Population Genetics, Evolutionary Biology, and Biological Conservation of Neotropical Carnivores

Ruiz-García, Manuel; Vásquez, Catalina; Murillo, Andrea; Pinedo-Castro, Myreya; Alvarez, Diana
Fonte: Nova Science Publishers, Inc. Publicador: Nova Science Publishers, Inc.
Formato: 413-464
Relevância na Pesquisa
56.03%
A total of 250 jaguars directly sampled in the wild (Guatemala, Costa Rica, Colombia, Venezuela, French Guiana, Peru, Bolivia and central and western Brazilian Amazon) were analyzed for 12 DNA microsatellite loci and for three mitochondrial genes (NADH5, 16S rRNA and ATP8). The main results were as follows: 1- The levels of gene diversity were very high for microsatellites as well as for mt markers. These levels were higher than those obtained in other studies by Eizirik’s team. Explanations of why this occurred are herein discussed. 2- The highest gene diversity levels were found for the western Amazon areas for microsatellites as well as mt markers, with lower gene diversity levels for areas far as away as central and eastern Brazil and Central America. 3- The levels of genetic heterogeneity were small for the samples classified by morphological subspecies, by countries and by considering the Amazon River as a barrier. Therefore, there is no clear evidence of the existence of “real” subspecies in the jaguars, especially, for the forms of South America. It was also clear that the Amazon River was not a geographical barrier for this large species, disagreeing with the claims of Eizirik et al....

Population structure and cultural geography of a folktale in Europe.

Ross, Robert M; Greenhill, Simon J; Atkinson, Quentin D
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica Formato: 9 pages
Relevância na Pesquisa
56.04%
Despite a burgeoning science of cultural evolution, relatively little work has focused on the population structure of human cultural variation. By contrast, studies in human population genetics use a suite of tools to quantify and analyse spatial and temporal patterns of genetic variation within and between populations. Human genetic diversity can be explained largely as a result of migration and drift giving rise to gradual genetic clines, together with some discontinuities arising from geographical and cultural barriers to gene flow. Here, we adapt theory and methods from population genetics to quantify the influence of geography and ethnolinguistic boundaries on the distribution of 700 variants of a folktale in 31 European ethnolinguistic populations. We find that geographical distance and ethnolinguistic affiliation exert significant independent effects on folktale diversity and that variation between populations supports a clustering concordant with European geography. This pattern of geographical clines and clusters parallels the pattern of human genetic diversity in Europe, although the effects of geographical distance and ethnolinguistic boundaries are stronger for folktales than genes. Our findings highlight the importance of geography and population boundaries in models of human cultural variation and point to key similarities and differences between evolutionary processes operating on human genes and culture.

Next Generation Population Genomics in the Guppy (Poecilia reticulata); Populationsgenomik der nächsten Generation im Guppy (Poecilia reticulata)

Willing, Eva-Maria
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
EN
Relevância na Pesquisa
56.05%
Population genetic studies estimate allele frequency distributions and the change of these frequencies over time in order to infer the demographic history of natural populations. Such studies aim to explain how adaptation and speciation have occurred. Until recently, inferences in non-reference taxa have been based on very few loci due to the high cost of developing a large set of markers de-novo. Only in established model organisms with a known reference genome was it possible to study genome-wide patterns of sequence variation. However, the advent of Next Generation Sequencing (NGS) technologies has revolutionized the field of whole genome research, and facilitated the development of genome-wide genetic markers. The guppy (Poecilia reticulata) is an important model organism in ecological genetics. Adaptation of guppies to contrasting upland and lowland habitats has been extensively studied with respect to behavior, morphology and life history. Guppy populations are able to adapt rapidly to new environments, presumably due to their high level of standing natural variation. However, it was previously not possible to deduce a genome-wide picture of genetic variability and to scan for the causative genomic regions under selection. In this thesis...

Stochastic Modeling and Simulation of Biological Phenomena with Applications in Population Genetics and in Cell Populations

Li, Biao
Fonte: Universidade Rice Publicador: Universidade Rice
Relevância na Pesquisa
66.12%
Stochastic modeling and simulation play important roles in population genetics, statistical genetics, cell biology, molecular biology and evolutionary theory. This thesis explores four aspects of stochastic modeling and simulation of biological phenomena with applications. Research carried out is focused on two major themes. The first one (Chapters 2 and 3) concerns application of stochastic modeling in genetics, specifically to identify biases in analysis of genetics data. Two problems that are considered are ascertainment bias in estimation of microsatellite diversity in interspecies comparisons, and sample-selection bias in comparing different methods of rare variant analysis. The second theme (Chapters 4 and 5) concerns application of Poisson and branching process models to understand various aspects of cell proliferation, using S-phase labeling. Two model systems are: transient dynamics of proliferation of neurogenic progenitors in mouse brain with emphasis on differentiation and apoptosis, and balanced growth under different assumptions concerning DNA-replication pattern. In the first part, we investigate factors that are influencing the ascertainment bias of microsatellite allele sizes and explore the impact on estimates of mutation rates. Microsatellite loci play an important role as markers for identification...

Population Regulomics: Applying population genetics to the cis-regulome

Ruths, Troy
Fonte: Universidade Rice Publicador: Universidade Rice
Relevância na Pesquisa
66.16%
Population genetics provides a mathematical and computational framework for understanding and modeling evolutionary processes, and so it is vital for the investigation of biological systems. In its current state, molecular population genetics is exclusively focused on molecular sequences (DNA, RNA, or amino acid sequences), where all application-ready simulators and analytic measures work only on sequence data. Consequently, in the early 2000s, when technologies became available to sequence entire genomes, population genetic approaches were naturally applied to mine out signatures of selection and conservation, resulting in the subfi eld of population genomics. Nearly every present genome project applies population genomic techniques to identify functional information and genome structure. Recent technologies have ushered in a similar wave of genetic information, this time focusing on biological mechanisms operating above the genome, most notably on gene regulation (regulatory networks). In this work, I develop a molecular population genetics approach for gene regulation, called population regulomics, which includes simulators and analytic measurements that operate on populations of regulatory networks. I conducted extensive data analyses to connect the genome with the cis-regulome...

Análise genética populacional de Prosopis rubriflora Hassl. ("Espinheiro") e Prosopis ruscifolia Griseb. ("Algaroba") (Leguminosae, Mimosoideae) em áreas de Chaco brasileiro = : Population genetics analysis of Prosopis rubriflora Hassl. ("Espinheiro") and Prosopis ruscifolia Griseb. ("Algaroba") (Leguminosae, Mimosoideae) in remnants of Brazilian Chaco; Population genetics analysis of Prosopis rubriflora Hassl. ("Espinheiro") and Prosopis ruscifolia Griseb. ("Algaroba") (Leguminosae, Mimosoideae) in remnants of Brazilian Chaco

Fábio de Matos Alves
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/11/2014 PT
Relevância na Pesquisa
56.05%
As áreas de Chaco em território sulamericano, representam a maior área de floresta seca contínua do continente. No Brasil, estas áreas são encontradas principalmente na porção sudeste do domínio, no estado de Mato Grosso do Sul, região sul-pantaneira. Talvez por serem áreas de pouca cobertura, o seu conhecimento ainda é incipiente. Embora novos projetos tenham sido realizados nestas áreas nos últimos anos, a sua crescente supressão pelas atividades de pecuária extensiva tem sido preocupante. Não há na região qualquer tipo de Unidade de Conservação a fim de preservar o patrimônio genético das espécies que lá ocorrem, muitas das quais têm sua distribuição limitada a esta fitofisionomia. Desta forma, estudos que visem o conhecimento da variabilidade genética ainda existente, principalmente em áreas em processo de degradação são fundamentais para o conhecimento da atual situação das populações existentes, para indicar métodos de conservação, bem como a propor políticas públicas visando a manutenção e conservação do Chaco brasileiro. A fim de efetuar estimativas da diversidade genética, o uso de marcadores moleculares tem sido empregado em diversos estudos de populações nas diversas formações vegetacionais...

Genome-Wide Association Studies in an Isolated Founder Population from the Pacific Island of Kosrae

Lowe, Jennifer K.; Maller, Julian B.; Pe'er, Itsik; Neale, Benjamin M.; Salit, Jacqueline; Kenny, Eimear E.; Shea, Jessica L.; Burkhardt, Ralph; Ji, Weizhen; Noel, Martha; Foo, Jia Nee; Blundell, Maude L.; Skilling, Vita; Garcia, Laura; Sullivan, Marcia L
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.07%
It has been argued that the limited genetic diversity and reduced allelic heterogeneity observed in isolated founder populations facilitates discovery of loci contributing to both Mendelian and complex disease. A strong founder effect, severe isolation, and substantial inbreeding have dramatically reduced genetic diversity in natives from the island of Kosrae, Federated States of Micronesia, who exhibit a high prevalence of obesity and other metabolic disorders. We hypothesized that genetic drift and possibly natural selection on Kosrae might have increased the frequency of previously rare genetic variants with relatively large effects, making these alleles readily detectable in genome-wide association analysis. However, mapping in large, inbred cohorts introduces analytic challenges, as extensive relatedness between subjects violates the assumptions of independence upon which traditional association test statistics are based. We performed genome-wide association analysis for 15 quantitative traits in 2,906 members of the Kosrae population, using novel approaches to manage the extreme relatedness in the sample. As positive controls, we observe association to known loci for plasma cholesterol, triglycerides, and C-reactive protein and to a compelling candidate loci for thyroid stimulating hormone and fasting plasma glucose. We show that our study is well powered to detect common alleles explaining ≥5% phenotypic variance. However...

Fine-scale genetic structure reflects sex-specific dispersal strategies in a population of sociable weavers (Philetairus socius)

van Dijk, Ren? E.; Covas, Rita; Doutrelant, Claire; Spottiswoode, Claire N.; Hatchwell, Ben J.
Fonte: Wiley Publicador: Wiley
Tipo: Article; published version
EN
Relevância na Pesquisa
56.03%
This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/mec.13308; Dispersal is a critical driver of gene flow, with important consequences for population genetic structure, social interactions and other biological processes. Limited dispersal may result in kin-structured populations in which kin selection may operate, but it may also increase the risk of kin competition and inbreeding. Here, we use a combination of long-term field data and molecular genetics to examine dispersal patterns and their consequences for the population genetics of a highly social bird, the sociable weaver (Philetairus socius), which exhibits cooperation at various levels of sociality from nuclear family groups to its unique communal nests. Using 20 years of data, involving capture of 6508 birds and 3151 recaptures at 48 colonies, we found that both sexes exhibit philopatry and that any dispersal occurs over relatively short distances. Dispersal is female-biased, with females dispersing earlier, further, and to less closely related destination colonies than males. Genotyping data from 30 colonies showed that this pattern of dispersal is reflected by fine-scale genetic structure for both sexes, revealed by isolation by distance in terms of genetic relatedness and significant genetic variance among colonies. Both relationships were stronger among males than females. Crucially...

Population Genetics of Species Associated with Deep-sea Hydrothermal Vents in the Western Pacific

Thaler, Andrew David
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
Relevância na Pesquisa
56.06%

Genetic diversity, population structure, and connectivity influence interactions among communities and populations. At hydrothermal vents in the western pacific, population structure in vent-associated species could occur at spatial scales ranging from vent sites separated by a few hundred meters to oceanic basins separated by more than 3000 kilometers. The spatial scale of population structure has important conservation implications; species that are well-connected across large geographic regions are more resilient to natural and anthropogenic disturbance. This dissertation examines the genetic diversity, population structure, and connectivity of 3 vent-associated species in the western Pacific. It first presents results from the development of microsatellite primers for Ifremeria nautilei, a deep-sea vent associated snail, then uses mitochondrial COI sequences and a suite of microsatellite markers to examine the broader connectivity of three vent-associated species, Ifremeria nautilei, Chorocaris sp. 2, and Olgasolaris tollmanni, across three back-arc basins in the western Pacific.

Within Manus Basin, no significant genetic differentiation was detected in populations of Ifremeria nautilei (based on COI and microsatellite)...

Testing for concordant equilibria between population samples

Huttley, Gavin Austin; Wilson, Susan
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.03%
A substantial body of theory has been developed to assess the effect of evolutionary forces on the distribution of genotypes, both single and multilocus, within populations. One area where the potential for application of this theory has not been fully appreciated concerns the extent to which population samples differ. Within populations, the divergence of genotype or haplotype frequencies from that expected under Hardy-Weinberg (HW) or linkage equilibrium can be measured as disequilibria coefficients. To assess population samples for concordant equilibria, an analytical framework for comparing disequilibria coefficients between populations is necessary. Here we present log-linear models to evaluate such hypotheses. These models have broad utility ranging from conventional population genetics to genetic epidemiology. We demonstrate the use of these log-linear models (1) as a test for genetic association with disease and (2) as a test for different levels of linkage disequilibria between human populations.

Mutation rate of 7 X-STRs of common use in population genetics

Glesmann,Laura A.; Martina,Pablo F.; Vidal Rioja,Lidia; Catanesi,Cecilia I.
Fonte: BAG. Journal of basic and applied genetics Publicador: BAG. Journal of basic and applied genetics
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
66.01%
Microsatellite loci analysis is a relevant tool in population genetic studies and also in paternity testing. In this field the X-chromosome STR loci are widely used for female offspring testing but their mutation rates are scarcely known. In this work we performed a mutation rate analysis of seven STR markers located in the X- chromosome specific region, in mother-son pairs and father-mother-daughter trios. Among 1015 allele transfers, we found only one change for a mother-daughter transmission in the DXS9898 locus, consisting of a loss of one single repeat. This finding allowed us to estimate a general mutation rate of μ=9.85 x 10-4 (2.49 x 10-4 - 5.49 x 10-2) which can be applied to population studies. This value is consistent with other reports on autosomal STR loci, suggesting that similar molecular mechanisms are acting on X and autosomal repetitive markers.