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Implications of evolutionary history and population structure for the analysis of quantitative trait loci in the ancient conifer Araucaria cunninghamiiScott, Leon J Unknown Date (has links)
Araucaria cunninghamii is an ancient tropical conifer with substantial value as a forestry species in Australia and Papua New Guinea, and has been subject to a genetic improvement program for more than 50 years. This study was undertaken to demonstrate the utility of quantitative genetic analysis in describing the genetic architecture of commercial traits in A. cunninghamii. Linkage maps were prepared using the pseudotestcross strategy in what was believed to be a wide interprovenance cross using microsatellites and AFLP. A very low rate of marker polymorphism and limited differentiation between the parental provenances was identified, resulting in low mapping efficiency. The population genetic structure of A. cunninghamii was assessed to establish the underlying causes for the limited differentiation and low marker heterozygosity and assess the implications for future analysis of quantitative traits. Despite the limited mapping efficiency, genetic maps were generated for both parents. The maternal map for individual H15 contained 14 linkage groups comprising of 51 AFLP and one microsatellite. The map covered 1290 cM, representing 89% of the estimated genome size. The paternal map for individual Gil24 was 633 cM, consisting of eight linkage groups. Genetic architecture of quantitative traits was examined with putative QTL identified for height, DBH and stem straightness; one was highly significant (p<0.01), three significant (0.01<p<0.05) and 13 suggestive (p<0.10). Significant QTL each accounted for 7-11% of the phenotypic variance with a high allele substitution effect (0.63-0.81). These QTL were likely to be associated with genes of moderate effect. The suggestive QTL each accounted for 3-6% of the phenotypic variance with an allele substitution effect of 0.40-0.63. Three genomic regions contributed to the expression of multiple traits at multiple ages. Stable QTL had decreasing phenotypic effects with increasing age. The population genetic survey characterised low levels of allelic diversity across the geographic range. Three broad regions were characterised; Papua New Guinea, Cape York and northern Queensland to NSW. There was limited differentiation between provenances within these regions, and high diversity within provenances. Limited genetic differentiation between provenances seems to be the result of genetic stability due to long overlapping generations, limited founder effects and a very low mutation rate. The latter may also contribute the low heterozygosity. Limited marker polymorphism and limited differentiation between provenances within broad regions are common features in A. cunninghamii. Therefore careful parental selection and alternative experimental approaches will be required before undertaking further analysis of quantitative traits.
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Genetic studies of colorectal cancer /Skoglund, Johanna, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
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Genetic dissection of multifactorial disease models in the rat /Jiao, Hong, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.
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Multiple sclerosis : linkage analysis and DNA variation in a complex trait /Modin, Helena, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
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Studies of genetic and environmental influences on Parkinson's disease /Wirdefeldt, Karin, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.
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Fine mapping of the chromosome 15q13-14 schizophrenia linkage region /Stephens, Sarah H. January 2008 (has links)
Thesis (Ph.D. in Human Medical Genetics) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 112-128). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Statistical methods for analyzing genomic data with consideration of spatial structures /Yu, Xuesong, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 121-126).
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Epidemiology of hereditary prostate cancer : genetic analysis of susceptibility loci incorporating clinical characteristics /Goode, Ellen Lee. January 2000 (has links)
Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 137-144).
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Political Representation in the European Union : A Multi-Channel ApproachMårtensson, Moa January 2015 (has links)
The European Union (EU) is the most far-reaching attempt yet undertaken to institutionalize democratic policy-making beyond the nation-state. To what extent, and in what ways, do various channels of representation contribute towards the realization of this aim? This dissertation takes stock of current research on the EU’s system of representation, and seeks to expand its agenda so that this central question can be properly addressed. In contrast to prior empirical work in the field, the dissertation employs research designs that incorporate several forms of representation into a unified evaluative framework. This multi-channel approach to political representation paves the way for a systematic comparison of how different forms of representation (electoral, territorial and corporate) perform in the EU context. It also makes possible an empirical assessment of a key proposition in current representation theory: that elections, in large and heterogeneous political systems, are outperformed by other forms of representation. The three articles in the dissertation draw on existing cross-country data, interviews with policy-makers and a new dataset collected by the author. They scrutinize representation in three principal channels: electoral representation in the European Parliament, government representation in the preparatory bodies of the Council of Ministers, and representation through organized interests that seek to influence EU policy. The first article examines the balance of power that has emerged between these three channels of representation in the EU’s legislative process, and how the current balance is likely to affect the Union’s legitimacy. The second article investigates how different channels of representation perform in terms of providing linkage between Brussels-based representatives and their domestic principals. The third article examines the extent to which different channels of representation contribute to the coordination of EU policy-making domestically, at the European level, and across the two levels of government. Finally, this dissertation makes a methodological contribution by applying social network analysis (SNA) to classic problems of representation within and across different channels of representation. This approach is novel to the field. Researchers should be able to exploit SNA and relational data fruitfully in the future, in the study of representational relationships in the EU and numerous other contexts.
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Linkage mapping in Haliotis midae using gene-lnked markersJansen, Suzaan 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Haliotis midae, or more commonly known as Perlemoen, is an abalone species found along the coast of South Africa. It is the only cultured abalone species in South Africa and has a high demand abroad. Due to its popularity as a seafood delicacy, illegal harvesting has taken its toll on Perlemoen numbers. This increases the need for sustainable farming efforts and efficient implementation of law enforcement practices against poachers. Abalone farms make use of a limited number of broodstock for breeding, so it is necessary to ensure that genetic effects such as inbreeding and bottlenecks do not interfere with the viability of the offspring. Research that focuses on the genetics of Perlemoen will greatly aid the farms to continue sustainable production of this species as well as enhance their breeding efficiency. This study focuses on the construction of a linkage map for H. midae that will allow the future identification of markers associated with genes important to production, such as growth and disease resistance. Identification of these genes will allow breeders to select genetically superior abalone that will be used for breeding programmes in which the phenotype of the offspring will be enhanced.
For the construction of a linkage map it is necessary to have enough informative markers for mapping. In this study, gene-linked microsatellite markers were developed by screening a contig assembly of H. midae’s transcriptome. Ninety-eight primer pairs could be developed from the contigs and 60 loci produced amplification products. Twenty-six microsatellites were found to be polymorphic (27% success rate).
In addition to these markers, 239 previously developed microsatellites and 48 gene-linked SNPs were used to develop sex-average and sex-specific linkage maps in four full-sib families consisting of approximately 100 offspring each. Of these markers 99 were informative in family DS1 (31% success rate), 81 in family DS2 (26%), 77 in family DS5 (24%) and 71 in family DS6 (23%). These markers were used for linkage analysis (LOD>3). The average number of linkage groups for the sex-average maps ranged from 17-19. The average genome length for these maps ranged from 700cM to 1100cM with an average marker spacing of 8cM. The sex-specific maps’ linkage groups ranged from 13-17 with an average genome length of 600cM to 1500cM. The average marker spacing was approximately 16cM. The integrated map was constructed by merging the sex-average maps. This map contained 25 linkage groups with an average genome length calculation of 1700cM and an average marker spacing of 9.3cM.
The linkage maps created in this study are the first to utilize SNPs in H. midae. Further incorporation of SNPs into linkage maps will enhance the density. The maps created in this study are of medium-density (65%) and provide a link to the development of high-density linkage maps to facilitate associations of phenotypic traits to certain markers, to so that QTL mapping can be performed. This information can be used for marker-assisted selection to produce genetically superior abalone. / AFRIKAANSE OPSOMMING: Haliotis midae, of meer algemeen bekend as Perlemoen, is 'n klipkous spesie wat langs die kus van Suid-Afrika voorkom. Dit is die enigste gekweekte klipkous spesie in Suid-Afrika en het 'n hoë aanvraag in die buiteland. As gevolg van sy gewildheid as 'n seekos lekkerny, het onwettige stropery sy tol geneem op Perlemoen getalle. Hierdie verhoog die behoefte vir volhoubare boerdery pogings en doeltreffende implementering van wetstoepassing teen stropers. Perlemoenplase maak gebruik van 'n beperkte aantal broeidiere vir teling, dus is dit nodig om te verseker dat genetiese effekte soos inteling en genetiese bottelnekke nie inmeng met die lewensvatbaarheid van die nageslag nie. Navorsing wat fokus op die genetika van Perlemoen sal grootliks die plase steun om die volhoubare produksie van hierdie spesie voort te sit, sowel as hul teling doeltreffendheid te verbeter. Hierdie studie fokus op die ontwikkeling van 'n genetiese koppelingskaart vir H. midae, wat die toekomstige identifisering van die merkers wat verband hou met die gene wat belangrik is vir die produksie, soos groei en weerstand teen siektes sal verbeter. Identifisering van hierdie gene sal toelaat dat telers genetiese voortreflike Perlemoen kan kies vir teelprogramme waartydens die fenotipe van die nageslag sal verbeter word.
Vir die ontwikkeling van 'n genetiese koppelingskaart is dit nodig om genoeg informatiewe merkers vir die kartering te hê. In hierdie studie, is geen-gekoppelde mikrosatelliet-merkers ontwikkel deur ‘contig’ data van H. midae se transkriptoom te ondersoek. Agt en negentig inleier pare kon ontwikkel word uit die ‘contigs’ en 60 loki kon ‘n amplifiseringsproduk lewer. Ses-en-twintig mikrosatelliete was polimorfies (27% suksessyfer).
Bykomend tot hierdie ontwikkelde merkers is 239 voorheen ontwikkelde mikrosatelliete en 48 geen-gekoppelde SNPs gebruik om geslagsgemiddelde en geslagspesifieke koppelingskaarte in vier volsib families, wat uit ongeveer 100 nageslag elk bestaan, te ontwikkel. Van hierdie merkers was 99 informatief in familie DS1 (31%), 81 in die familie DS2 (26%), 77 in die familie DS5 (24%) en 71 in die familie DS6 (23%). Hierdie merkers is gebruik vir 'n koppelingsanalise (LOD>3). Die gemiddelde aantal koppelingsgroepe vir die geslagsgemiddelde kaarte het gewissel van 17-19. Die gemiddelde genoom lengte vir hierdie kaarte het gewissel van 700cM tot 1100cM met 'n gemiddelde merker spasiëring van 8cm. Die koppelingsgroepe van die geslagspesifieke kaarte het gewissel van 13-17 met 'n gemiddelde genoom lengte van 600cM tot 1500cM. Die gemiddelde merker spasiëring was ongeveer 16cm. Die geïntegreerde kaart is saamgestel deur die samesmelting van die geslagsgemiddelde kaarte. Die kaart toon 25 koppelingsgroepe met 'n gemiddelde berekende genoom lengte van 1700cM en' n gemiddelde merker spasiëring van 9.3cM.
Die genetiese koppelingskaarte wat in hierdie studie ontwikkel is, is die eerste om SNPs te gebruik in H. midae. Verdere insluiting van SNPs in koppelingskaarte sal die digtheid verhoog. Die kaarte wat in hierdie studie ontwikkel is, is van medium digtheid (65%) en bied 'n stap nader aan die ontwikkeling van hoë digtheid koppelingskaarte om fenotipiese eienskappe met sekere merkers te assosieer, vir kwantitatiewe kenmerk lokus kartering. Hierdie inligting kan gebruik word vir merker bemiddelde seleksie om geneties verbeterde Perlemoen te produseer.
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