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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.
51

Sistemàtica molecular, filogeografia i genètica de la conservació de mustèlids i macacs

Marmi Plana, Josep Maria 23 June 2006 (has links)
Els treballs realitzats en aquesta tesi tenen com objectius l'aplicació de la sistemàtica molecular i la filogeografia per resoldre relacions filogenètiques, clarificar la taxonomia i descriure la història de les poblacions de les espècies incloses dins de dos grups de mamífers d'elevat interés conservacionista: els mustélids (família Mustelidae) i els macacs (génere Macaca).L'ús de diferents marcadors genétics mitocondrials (el gen citocrom b i la regió control) i un de nuclear (les seqüencies flanquejants d'una regió repetitiva) ha permés reconstruir les relacions filogenètiques entre 33 espècies de mustelids; delimitar quatre grups filogeogràfics en el teixò euroasiàtic (Meles meles); detectar la venta de productes derivats d'aquesta espècie en països on està protegida; i estudiar el procès d'especiació del macac japonès (Macaca fuscata). A partir dels resultats obtinguts també s'han proposat canvis en la taxonomia d'aquests grups. Al final de la tesi es fan reflexions sobre el paper que desenvolupen els marcadors moleculars en la sistemàtica, sobre com classificar aquelles espècies que no ha finalitzat els seus processos d'especiació i sobre les aplicacions de la sistemàtica, la biologia evolutiva i la genètica en la conservació de la biodiversitat. / The objectives of this thesis were the application of molecular systematics and phylogeography to resolve phylogeny, to clarify taxonomy and to study the population history of species included within two groups of mammals of high conservation interest: the mustelids (Family Mustelidae) and the macaques (Genus Macaca).Using different mitochondrial (cytochrome b gene and control region) and nuclear (flanking sequences of a repetitive region) markers, we have been able to reconstruct the phylogeny of 33 mustelid species; to delimit four phylogeographic groups in the Eurasian badger (Meles meles); to detect the trade of Eurasian badger products in countries where this species is protected; and to study the speciation process of the Japanese macaque (Macaca fuscata). According to our results we have also proposed taxonomic changes in these groups.At the end of the thesis, there are also some reflections about the role of genetic markers in systematics; about how to classify the species that have not finished their speciation process; and about the application of systematics, evolutionary biology and genetics in conservation biology.
52

Étude de la fonction du promoteur foetal A[gamma] dans la régulation de la commutation de l'hémoglobine foetale à adulte

Beauchemin, Hugues January 2008 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal
53

Population Genetic Structure of Black Grouse (Tetrao tetrix) : From a Large to a Fine Scale Perspective

Corrales Duque, Carolina January 2011 (has links)
Black grouse (Tetrao tetrix) is a bird species with a lek mating system found in the Palearctic boreal taiga. It is assumed that it has a continuous distribution along Scandinavia and Siberia, whereas in Central Europe it has declined during the last decades. The primary objective of this thesis was to obtain a deeper understanding of the history, systematic classification and the genetic structure of black grouse on different geographical scales using microsatellites and control region mtDNA sequences (CR). I determined how much the mating system, habitat fragmentation and historical population processes have influenced the partitioning of genetic diversity in this species. Phylogeographical results are consistent with a demographic population expansion, and the patterns of postglacial dispersal suggest that a glacial refugium was located somewhere in central Asia, and from there black grouse spread out to Europe following the retreat of glacial ice sheets. I suggest that the two European black grouse subspecies, T. t. Tetrix and T. t. britannicus correspond to only one subspecies: T. t. tetrix, and that this lineage has diverged from T.t. viridanus, a subspecies found in Kazakhstan. The British population is significantly divergent from the remaining Eurasian samples for microsatellites but it is not for mtDNA. Therefore, they should regard as a separate Management Unit and not as a subspecies. Furthermore, British black grouse occur in three independent genetic units, corresponding to Wales, northern England/southern Scotland and northern Scotland. There was also genetic structure within Sweden. Habitat fragmentation is the main cause of population genetic structure in southern Swedish black grouse. In contrast, low levels of genetic differentiation and high connectivity were found in northern Sweden due to female-biased dispersal. On a finer geographical scale, I found genetic differences between leks due to a mixture of related and unrelated individuals within leks. However, mean relatedness values hardly differed from zero. Some leks were similar to one another and I interpret this as a result of variation in local reproductive success and philopatry. These factors would cause genetic structuring but this by itself would not reveal that kin selection is operating within black grouse leks.
54

Hybridní původ bobrů ve střední Evropě / Hybrid origin of beavers in Central Europe

Albrechtová, Alena January 2011 (has links)
The aim of the master diploma work is to investigate origin of Czech populations and genetic variability of almost all Eurasian populations of the European beaver (Castor fiber). For our purposes we collected specimens from Czech populations, reintroduced population in Kirov district in Russia and all European and Asian refugia. At the end of the 19th century the species was on the verge of extinction due to overhunting, surviving only in eight isolated refugial areas. The population size at the end of the 19th century was estimated as 1 200 animals. The number of individuals has increased thanks to the legal protection and reintroductions. The current population size is estimated at 640 000. It is obvious that the populations of beaver have recently undergone severe bottleneck. Beaver was completely extirpated in the Czech Republic in the 18th century. Since the 80th of the 20th century beavers re-established in the Czech Republic due to migration from neighbouring countries and reintroduction programmes, however we knew only little about the origin of beavers in the Czech Republic. I showed that our beavers are derived from individuals in France, Germany, Norway and east Europe. Mitochondrial DNA of Castor canadensis has not been found in Czech beavers. I studied microsatellite loci (first use for...
55

Effects of Migratory Habit on the Genetic Diversity of Avian Populations from the Oak Openings in Northwest Ohio

Estopinal, Ashley 20 November 2013 (has links)
No description available.
56

Molecular, morphological, and biogeographic resolution of cryptic taxa in the Greenside Darter <i>Etheostoma blennioides</i>complex

Haponski, Amanda E. January 2007 (has links)
No description available.
57

Garça-vaqueira (Bulbucus ibis): a diversidade genética no estudo do comportamento reprodutivo e na caracterização da população invasora brasileira

Silva, Emmanuel Moralez da 05 March 2013 (has links)
Made available in DSpace on 2016-06-02T20:20:34Z (GMT). No. of bitstreams: 1 4932.pdf: 1990172 bytes, checksum: 7025c9dd589a8c2a6771bc24539895b5 (MD5) Previous issue date: 2013-03-05 / Universidade Federal de Sao Carlos / The genetic diversity of the cattle egret (Bubulcus ibis) was analyzed to investigate reproductive behavior and characterize Brazilian populations of the species. Genotypes at seven microsatellite loci were used to investigate the occurrence of more than one female laying eggs in the same nest, characterizing the occurrence of multiple maternity. DNA was extracted from swabs collected from the outer surface of eggs and sexed; males were excluded. Forty-eight clutches from two breeding seasons (2010 and 2011) were genetically analyzed. Thirty-nine eggs laid by a second or third female were recorded. In five nests, the first egg of the clutch was from a different female, the laying happening prior to that of the incubating female. Suggesting nest takeover by another pair of egrets that kept the pre-existing eggs together with its own clutch. In the other 43 nests, the hypothesis of brood parasitism was posed to explain why one or two additional females were found laying eggs in a nest. A 463-bp fragment of the mitochondrial DNA control region Domain I was amplified for 148 individuals from seven Brazilian populations to investigate genetic-population and demographic parameters. Genetic diversity indices, the population structure tests Fst and AMOVA, a haplotype network, mismatch distribution and neutrality tests (Tajima s D, Fu s Fs, Fu and Li s D* and F*, Ramos-Onsins and Rozas R2) revealed the following: i) a high level of diversity was recorded for the cattle egret in Brazil in comparison to other closely related species studied in the country; ii) genetic diversity levels determined for the Brazilian regions are similar; iii) genetic structuring was not observed between the seven studied populations; and iv) the different tests performed to determine demographic expansion revealed no significant results. This is the first genetic characterization study for Bubulcus ibis to date and the findings indicate a high degree of plasticity in reproductive behavior and confirm a marked dispersion behavior of the species, leading to the homogenization of Brazilian populations. / A diversidade genética da garça-vaqueira (Bubulcus ibis) foi utilizada para se investigar o comportamento reprodutivo e para se caracterizar populações brasileiras da espécie. Genótipos em locos de microssatélites foram utilizados na detecção da presença de mais de uma fêmea ovipositando em um mesmo ninho, o que pode caracterizar a ocorrência de maternidade múltipla. O DNA extraído dos swabs coletados na superfície externa dos ovos foi sexado e eventuais amostras de machos foram excluídas. Quarenta e oito ninhadas, de duas temporadas reprodutivas (2010 e 2011) foram analisadas geneticamente. Foram registrados 39 ovos ovipositados por uma segunda ou terceira fêmea. Em 33 ninhos foram encontrados genótipos distintos de duas fêmeas e em seis ninhos genótipos de três fêmeas. Em cinco ninhos o primeiro ovo na sequência de oviposição mostrou-se ser de uma fêmea diferente, tendo a oviposição acontecido previamente àquela da fêmea incubante. Esse achado foi explicado supondo a tomada de ninho por um segundo casal de garças, com a manutenção do ovo pré-existente juntamente com os da própria ninhada. Nos outros 43 ninhos, a presença das fêmeas extras foi explicada hipotetizando a ocorrência de parasitismo de ninho intraespecífico. Um fragmento de 463 pb do Domínio I da região controladora do DNA mitocondrial foi amplificado para 148 indivíduos para a investigação de parâmetros genéticopopulacionais e processos demográficos nas sete populações estudadas. A estimativa de índices de diversidade genética, testes de estruturação populacional Fst e AMOVA, a construção de uma rede de relação entre haplótipos, a análise de mudanças no tamanho populacional pela mismatch distribution e a realização de testes de neutralidade (D de Tajima, Fs de Fu, D* e F* de Fu e Li, R2 de Ramos-Onsins e Rozas) permitiram identificar: i) um nível alto de diversidade genética para B. ibis no Brasil, quando comparado a espécies proximamente relacionadas estudadas no país; ii) níveis semelhantes de diversidade genética determinados para as regiões brasileiras; iii) ausência de estruturação genética entre as sete populações estudadas; e iv) ausência de sinais de expansão demográfica pelos testes realizados. Os resultados aqui apresentados são os primeiros resultados genéticos na espécie até o momento e apontam para uma alta plasticidade no comportamento reprodutivo e confirmam a dispersão bastante acentuada da espécie, levando a homogeneização das populações brasileiras.

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