Dissertations / Theses: 'Quantitative trait locis'

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Polineni, Pavana. "Developing a web accessible integrated database and visualization tool for bovine quantitative trait loci." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/2449.

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A quantitative trait locus (QTL) is the location of a gene that affects a trait that is measured on a quantitative (linear) scale. Many important agricultural traits such as weight gain, milk fat content and intramuscular fat in cattle are quantitative traits. There is a need to integrate genomic sequence data with QTL data and to develop an analytical tool to visualize the data. Without integration, application of this data to agricultural enterprise productivity will be slow and inefficient. My thesis presents a web-accessible tool called the Bovine QTL Viewer developed to solve this problem. It consists of an integrated database of bovine QTL and the QTL viewer to view the QTL and their relative chromosomal position. This tool generates dynamic and interactive images and supports research in the field of genomics. For this tool, the data is modeled and the QTL viewer is developed based on the requirements and feedback of experts in the field of bovine genomics.

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Podisi, Baitsi Kingsley. "Quantitative trait loci mapping of sexual maturity traits applied to chicken breeding." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5561.

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Many phenotypes are controlled by factors which include the genes, the environment, interactions between genes and interaction between the genotypes and the environment. Great strides have been made to understand how these various factors affect traits of agricultural, medical and environmental importance. The chicken is regarded as a model organism whose study would not only assist efforts towards increased agricultural productivity but also provide insight into the genetic determination of traits with potential application in understanding human health and disease. Detection of genomic regions or loci responsible for controlling quantitative traits (QTL) in poultry has focussed mainly on growth and production traits with limited information on reproductive traits. Most of the reported results have used additive-dominance models which are easy to implement because they ignore epistatic gene action despite indications that it may be important for traits with low heritability and high heterosis. The thesis presents results on the detection of loci and genetic mechanisms involved in sexual maturity traits through modelling both additive-dominance gene actions and epistasis. The study was conducted on an F2 broiler x White Leghorn layer cross for QTL detection for age, weight, abdominal fat, ovary weight, oviduct weight, comb weight, number of ovarian yellow follicles, a score for the persistence of the right oviduct and bone density. In addition, body weight QTL at 3, 6, 12, 24, 48 and 72 weeks of age, QTL for growth rate between the successive ages and QTL for the parameters of the growth curve were also detected. Most of the QTL for traits at sexual maturity acted additively. A few of the QTL explained a modest proportion of the phenotypic variation with most of the QTL explaining a small component of the cumulative proportion of the variation explained by the QTL. Body weight QTL were critical in determining the attainment of puberty. The broiler allele had positive effects on weight at first egg and negative effects on age at first egg. Most QTL affecting weight at first egg overlapped with QTL for age at first egg and for early growth rate (6-9 weeks) suggesting that growth rate QTL are intimately related to the onset of puberty. Specific QTL for early and adult growth were detected but most QTL had varying influence on growth throughout life. Chromosome 4 harboured most of QTL for the assessed traits which explained the highest proportion of the phenotypic variation in the traits confirming its critical role in influencing traits of economic importance. There was no evidence for epistasis for almost all the studied traits. Evidence for role of epistasis was significant for ovary weight and suggestive for both growth rate and abdominal fat.

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Lu, Yue. "Genetic mapping of quantitative trait loci for slow-rusting traits in wheat." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/32179.

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Doctor of Philosophy
Department of Agronomy
Guihua Bai
Allan K. Fritz
Wheat leaf rust, caused by Puccinia triticina, is an important fungal disease worldwide. Growing resistant cultivars is an effective practice to reduce the losses caused by the disease, and using slow-rusting resistance genes can improve the durability of rust resistance in the cultivars. CI13227 is a winter wheat line that shows a high level of slow-rusting resistance to leaf rust and has been studied extensively. In this research, two recombinant inbreed line (RIL) populations derived from CI13227 x Suwon (104 RILs) and CI13227 x Everest (184 RILs) and one doubled haploid (DH) population derived from CI13227 x Lakin with 181 lines were used to identify quantitative trait loci (QTLs) for slow leaf rusting resistance. Each population and its parents were evaluated for slow-rusting traits in two greenhouse experiments. A selected set of 384 simple sequence repeat markers (SSRs), single nucleotide polymorphism markers (SNPs) derived from genotyping-by-sequencing (GBS-SNPs) or 90K-SNP chip (90K-SNPs) were analyzed in the three populations. Six QTLs for slow-rusting resistance, QLr.hwwgru-2DS, QLr.hwwgru-7BL, QLr.hwwgru-7AL, QLr.hwwgru-3B_1, QLr.hwwgru-3B_2, and QLr.hwwgru-1D were detected in the three populations with three stable QTLs, QLr.hwwgru-2DS, QLr.hwwgru-7BL and QLr.hwwgru-7AL. These were detected and validated by Kompetitive Allele-Specific PCR (KASP) markers converted from GBS-SNPs and 90K-SNPs in at least two populations. Another three QTLs were detected only in a single population, and either showed a minor effect or came from the susceptible parents. The KASP markers tightly linked to QLr.hwwgru-2DS (IWB34642, IWB8545 and GBS_snpj2228), QLr.hwwgru-7BL (GBS_snp1637 and IWB24039) and QLr.hwwgru-7AL (IWB73053 and IWB42182) are ready to be used in marker-assisted selection (MAS) to transfer these QTLs into wheat varieties to improve slow-rusting resistance in wheat.

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Clevinger, Elizabeth. "Mapping Quantitative Trait Loci for Soybean Quality Traits from Two Different Sources." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33468.

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Soybeans are economically and agriculturally the most important legume in the world, providing protein and oil to the food and animal feed industries and base ingredients for hundreds of chemical products. Their value could be enhanced, however, if the oil and protein content remained high and the oligosaccharide and phytate contents were lowered to make soybeans more acceptable for human and animal consumption. A soybean population of 55 families segregating for genes controlling quality traits was chosen for this study. Both parental lines have high sucrose and low stachyose. The former contains a high level of phytate while the latter is low phytate. The objective of this experiment was to determine whether or not both parents had the same gene(s) for low stachyose. An additional objective was to determine quantitative trait loci (QTL) controlling quality traits: sucrose, stachyose and phytate. An acetonitrile precipitation method and a modified colorimetric method were used to determine amounts of sugars and phytate, respectively. The phenotypic data for stachyose was analyzed and it was determined that two recessive genes control low stachyose content in this population. A map was constructed using 141 SSR markers and 15 molecular linkage groups (MLGs) were identified. After analyzing trait and marker data in QTL Cartographer, potential QTL were found on MLGs: B1, C2, D1b, F, M and N. Sucrose and stachyose QTL were identified on B1, C2, M and N. Phytate QTL were observed on B1, D1b, F and N. The markers identified for quality traits in this population may be useful in marker-assisted selection and the germplasm should be useful for the development of a cultivar.
Master of Science

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Shimomura, Koichiro. "Quantitative trait locus analysis of agronomic traits in weedy cucumber lines for breeding." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263362.

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Nyström, Per-Erik. "Quantitative trait loci in pig production /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5712-2.pdf.

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Turri, Maria Grazia. "Mapping of behavioural quantitative trait loci." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:89823fa1-c1d3-49e3-acb9-46da18b12245.

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Anxiety is a common disorder which affects about 25% of the population and whose pathophysiology is still poorly understood. Animal models of disease have been widely used to investigate the molecular basis of human disorders, including psychiatric illnesses. This thesis is about the study of the genetic basis of a mouse model of anxiety. I have carried out a QTL mapping study of behavioural measures thought to model anxiety. I report results from 1,636 mice, assessed for a large number of phenotypes in five ethological tests. Mice belonged to two F2 intercrosses originated by four lines generated in a replicate selection experiment. By comparing mapping results between the two crosses, I have demonstrated that selection operated on the same relatively small number of loci in the four selected lines. Analysis of genetic effect of QTL across phenotypes has allowed me to identify loci with specific roles on different dimensions of anxious behaviour, therefore enhancing our understanding of the anxiety phenotype in mice. For some of these QTL I have also accomplished fine mapping experiments: a locus on chromosome 15 is now contained in an interval of only 3 centimorgans. This work is the basis for further molecular dissection of the genetic loci that underlie anxiety and provides a starting point for the discovery of genes involved in a common psychiatric condition.

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Joehanes, Roby. "Multiple-trait multiple-interval mapping of quantitative-trait loci." Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1605.

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Somorjai, Ildikó M. L. "Quantitative trait loci for fitness traits in Arctic charr, conservation in rainbow trout and correlations among traits." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ61949.pdf.

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Joehanes, Roby. "Generalized and multiple-trait extensions to Quantitative-Trait Locus mapping." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1919.

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Kadarmideen, Haja Najeemudin. "Statistical methods to map quantitative trait loci for binary traits in half-sib populations." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ33306.pdf.

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Pinheiro, Cassia Renata. "Mapeamento de QTL (Quantitative Trait Loci) associados à resposta do maracujá-doce à bacteriose usando a abordagem de modelos mistos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11137/tde-23062015-161305/.

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O maracujazeiro-doce (Passiflora alata Curtis) é uma espécie de cruzamento e diploide (2n = 18) que vem se destacando no Brasil por alcançar melhores cotações no mercado de frutas. Apesar disso, é sensível às adversidades em monocultura, sendo extremamente afetada por variações climáticas, pragas e doenças, dentre elas, a bacteriose causada por Xanthomonas axonopodis pv. passiflorae. O patógeno é endêmico no país, apresentando considerável variabilidade genética nas populações naturais. O presente trabalho teve como objetivo contribuir para o melhoramento genético do maracujazeiro-doce por meio do mapeamento de QTL (Quantitative Trait Loci) relacionados à resistência à bacteriose de uma população F1 segregante, composta de 100 indivíduos e oriunda do cruzamento simples entre dois acessos não endogâmicos. A população foi mantida em casa de vegetação, em delineamento em blocos ao acaso, e foi inoculada com três isolados bacterianos, M129, PA8-2 e AP302, durante 2010, 2012 e 2013, respectivamente. Aos 14 dias após a inoculação, as folhas foram fotografadas e a partir das imagens digitalizadas foram mensuradas as áreas: sadia, de clorose, necrose e lesão (soma das áreas de clorose e necrose), além da área total da folha. Inicialmente, foi realizada uma análise exploratória dos dados e subsequentemente foram selecionados os caracteres área de necrose e de lesão foliar para fins de mapeamento de QTL. Para tanto foi usada uma estratégia desenvolvida para a detecção de QTL em F1 segregantes, com base em modelos mistos, considerando diferentes estruturas de variância e covariância, visando explicar os padrões de variação existentes. A herdabilidade variou de 14% a 64% para o carater necrose, e se manteve estável (28%) para o carater área de lesão, nos três anos de avaliação. Com base em um mapa de ligação integrado previamente construído, foi realizado o mapeamento de QTL por intervalo composto. Foram identificados 20 QTL, sendo 9 deles referentes à necrose e 11 referentes à lesão. Os efeitos individuais variaram de 0,2% a 15,7%, sendo que dois QTL de maior efeito (R² = 15,7%) foram identificados em resposta ao isolado PA8-2, um localizado no grupo de ligação III e o outro no IV do mapa genético integrado do maracujazeiro-doce. Essas informações, aliadas a outros estudos relacionados à produção de frutos, devem contribuir para o melhoramento do maracujazeiro-doce.
The sweet passion fruit (Passiflora alata Curtis) is an outcrossing and diploid (2n = 18) species that is achieving a competitive advantage in the fruit markets in Brazil. Nevertheless, the crop is sensitive to monoculture, being greatly affected by weather changes, pests and diseases, among them the bacterial disease caused by Xanthomonas axonopodis pv. passiflorae. The pathogen is endemic in the country, with considerable genetic variability in natural populations. The present study aimed to contribute to genetic improvement of sweet passion fruit through QTL (Quantitative Trait Loci) mapping associated with bacterial resistance using a F1 segregating population containing 100 individuals, which resulted from a single cross between two outbred accessions. The population was kept in a greenhouse, arranged in a randomized block design, and innoculated with three bacterial isolates, M129, PA8-2 and AP302, during 2010, 2012 and 2013, respectively. At 14 days after inoculation, the inoculated leaves were photographed, and the following areas from the scanned images were measured: healthy, with chlorosis, necrosis and leaf lesion (sum of the areas with chlorosis and necrosis), in addition to the total area of the leaf. Initially all data were investigated trough an exploratory analysis and those relative to necrotic and leaf lesion areas were subsequently used for QTLmapping. For that we used a strategy developed for QTL detection in F1 segregating populations based on composite interval mapping and mixed models considering different variance and covariance structures in order to explain the existing patterns of variation. Heritabilities ranged from 14% to 64% for the trait necrosis, and remained stable (28%) for the trait leaf lesion for the three years of evaluation. Based on an integrated linkage map previously constructed, we performed a composite interval mapping of QTL. Twenty QTL were identified, 9 of them related to necrosis and 11 related to the leaf lesion. The individual effects ranged from 0,2% to 15,7%, and two large-effect QTL (R² = 15,7%) were identified in response to isolate PA8-2, one assigned to linkage group III and other to linkage group IV of the integrated genetic map of sweet passion fruit. This information combined with other studies related to fruit production may contribute to sweet passion fruit breeding.

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Santana, Morant Dámaris. "Bayesian mapping of multiple quantitative trait loci." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012166.

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14

Carlborg, Örjan. "New methods for mapping quantitative trait loci /." Uppsala : Dept. of Animal Breeding and Genetics, Swedish Univ. of Agricultural Sciences ([Institutionen för husdjurens genetik], Sveriges lantbruksuniv.), 2002. http://projkat.slu.se/SafariDokument/210.htm.

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15

Martinez, de la Vega Octavio. "Quantitative trait loci estimation in plant populations." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358346.

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16

Logeswaran, Sayanthan. "Mapping quantitative trait loci in microbial populations." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4881.

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Linkage between markers and genes that affect a phenotype of interest may be determined by examining differences in marker allele frequency in the extreme progeny of a cross between two inbred lines. This strategy is usually employed when pooling is used to reduce genotyping costs. When the cross progeny are asexual the extreme progeny may be selected by multiple generations of asexual reproduction and selection. In this thesis I will analyse this method of measuring phenotype in asexual cross progeny. The aim is to examine the behaviour of marker allele frequency due to selection over many generations, and also to identify statistically significant changes in frequency in the selected population. I will show that stochasticity in marker frequency in the selected population arises due the finite initial population size. For Mendelian traits, the initial population size should be at least in the low to mid hundreds to avoid spurious changes in marker frequency in the selected population. For quantitative traits the length of time selection is applied for, as well as the initial population size, will affect the stochasticity in marker frequency. The longer selection is applied for, the more chance of spurious changes in marker frequency. Also for quantitative traits, I will show that the presence of epistasis can hinder changes in marker frequency at selected loci, and consequently make identification of selected loci more difficult. I also show that it is possible to detect epistasis from the marker frequency by identifying reversals in the direction of marker frequency change. Finally, I develop a maximum likelihood based statistical model that aims to identify significant changes in marker frequency in the selected population. I will show that the power of this statistical model is high for detecting large changes in marker frequency, but very low for detecting small changes in frequency.

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Yang, Jie. "Nonparametric functional mapping of quantitative trait loci." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0014762.

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Guo, Zhigang. "Novel methods for increasing efficiency of quantitative trait locus mapping." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/374.

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Ahmed, Helal Uddin. "Mapping stress tolerance genetic loci in Arabidopsis thaliana." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246628.

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Brasier, Kyle Geoffrey. "Physiological Traits and Quantitative Trait Loci Associated with Nitrogen Use Efficiency in Soft Red Winter Wheat." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/89216.

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Development of winter wheat (Triticum aestivum L.) cultivars capable of more efficient uptake and utilization of applied nitrogen (N) has the potential to increase grower profitability and reduce negative environmental consequences associated with N lost from the plant-soil system. The first study sought to evaluate genotypic variation for N use efficiency (NUE) and identify lines consistently expressing high or low NUE under two or more N rates in a total of 51 N-environments. The results indicated that significant genotype by N rate interactions were frequently observed when trials utilized at least three N rates and identified wheat lines with high and stable yield potential that varied in performance under low N conditions. In addition, NUE was associated with above-ground biomass at physiological maturity were found to be both highly heritable across multiple N supplies. In the second study, two bi-parental mapping populations having a common low ('Yorktown') and two high (VA05W-151 and VA09W-52) NUE parents were characterized to dissect the genetics underlying N response. The populations were evaluated in eight N-environments and genotyped using single-nucleotide polymorphism data derived from a genotyping-by-sequencing protocol to identify quantitative trait loci (QTL) associated with high NUE. Six QTL for NUE were identified on chromosomes 1D, 2D, 4A, 6A, 7A, and 7D that were associated with N use efficiency. The QTL on 2D and 4A co-localized with known loci governing photoperiod sensitivity and resistance to Fusarium head blight (caused by the fungal pathogen Fusarium graminearum Schwabe), respectively. Three of the identified QTL (6A, 7A, and 7D) were associated with NUE in previous investigations, while the QTL on 1D was novel. The final experiment employed a small panel of soft red winter wheat lines to study the effects of photoperiod alleles on chromosome 1D (Ppd-D1) on yield-related traits under three or five N rates that were variably split over two growth stages in eight environments. The results validated the effect of a photoperiod sensitive allele (Ppd-D1b) that was associated with increased grain yield across N rates in half of the Virginia testing environments and under low N rates in all Ohio testing sites at the expense of grain N content. Yield advantages conferred by the Ppd-D1b allele were attributable to increased floret fertility and kernel number per spike. The findings from these studies have direct application for winter wheat breeding programs targeting NUE improvements.
Doctor of Philosophy
Wheat (Triticum aestivum L.) products account for a significant percentage of the total dietary calories and protein consumed globally. To meet production demands, wheat requires efficient nitrogen (N) management to ensure continued grower profitability and to reduce negative environmental impacts of N lost from agricultural systems. This dissertation sought to evaluate variation among wheat lines for N use efficiency (NUE), assess the performance of wheat lines under multiple N supplies, validate traits that are associated with NUE, investigate the role of photoperiod sensitivity genes on N response, and identify regions of the wheat genome associated with high N use efficiency. These studies were conducted using panels of winter wheat lines grown under two or more N conditions over a combined 32 location-years. Results of Chapter I identified variation in cultivar response to N rates was more frequently observed when a greater number of N rates were used in trials of wheat N response. The first chapter also identified variation among wheat lines for NUE and identified lines that consistently produce high grain yields over N-location-years. In addition, above-ground biomass at physiological maturity was found to be strongly associated with grain yield under all N rates and was highly heritable in both studies. Chapter II utilized a combination of genetic and observable trait data to perform genetic analysis in two bi-parental populations grown in eight Nlocation-years. The study identified reproducible and significant genetic markers associated with NUE for application in wheat breeding programs. Upon analysis of photoperiod sensitive versus insensitive wheat lines in Chapter III, photoperiod sensitive wheat lines had a significant yield advantage under N-limited conditions in Ohio and across N treatments in half of the Virginia testing location-years. This resulted from an increased number of kernels per spike and fertile florets in photoperiod sensitive wheat lines. Results from this dissertation suggest that active breeding and selection for N response may be achieved through the employment of high NUE genes and the continued identification of adapted high NUE wheat parental lines.

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McClure, Matthew Charles Taylor J. "Genome scan in commercial angus cattle for quantitative trait loci influencing growth, carcass, and reproductive traits." Diss., Columbia, Mo. : University of Missouri-Columbia, 2009. http://hdl.handle.net/10355/7006.

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The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 6, 2010). Vita. Thesis advisor: Jeremy Taylor. "July 2009" Includes bibliographical references.

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Greenshields, David. "Isolation of adaptive quantitative trait loci in Antirrhinum." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/14950.

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Understanding the genetic basis of quantitative traits represents a huge goal in modern molecular and evolutionary biology. Here, the natural genetics of the genus Antirrhinum, within which separate species can be successfully interbred, are used to investigate differences in a range of morphological characteristics. The two species used in the study, Antirrhinum majus and Antirrhinum molle, have become adapted to very diverse environments and consequently exhibit large variance in a wide range of traits. A large-scale FI mutant screen, from a cross between a transposon-active A. majus line and A. molle, isolated segregating mutations for flower size, flower colour, trichome density and branching in self-pollinated F2 populations. Amplified Fragment Length Polymorphism analysis of the F2 and the use of molecular maps have shown the mutations generally correspond to known Quantitative Trait Loci, and the roles of genes linked to these regions are discussed. The technique sheds some light on the molecular and evolutionary mechanisms underpinning diversity in Antirrhinum and has implications for the use of transposon-tagging in locating QTL in other plant systems.

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Ritchey, Brian Michael. "Quantitative Trait Loci Mapping Of Macrophage Atherogenic Phenotypes." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1510080975338565.

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Atkinson, Jennifer L. "Quantitative trait locus analysis of growth in Arabidopsis thaliana." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/11892.

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Natural genetic variation found among accessions of Arabidopsis thaliana presents the opportunity of locating and identifying novel genes by means of quantitative trait locus (QTL) analysis. In this study, QTL analysis was used to identify loci involved in the genetic control of growth in A. thaliana. Non-destructive methods of analysis were developed and used for the measurements of growth rates in roots and leaves, whilst a simple size measurement of mature petals was used to assess growth in the floral organ. Two putative QTL were identified for primary root length, four for leaf number at day 32 and three for petal size in the Bay-0 x Shahdara recombinant inbred line (RIL) population. The Landsberg erecta x Columbia RIL population was also analysed, but no significant QTL were identified. The analysis suggested that, in all three organs, growth-rate is controlled by multiple small-effect QTL and is a highly plastic trait. Thus, minor environmental fluctuations during the course of experiments can lead to a large environmental variance in measurement of the traits, limiting the power of QTL analyses. Despite minimising these effects by adjusting growth techniques, the numbers and significance of QTL identified in each trait were lower then expected, and for the trait of relative growth rate in leaves no significant QTL were identified.

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Awad, Ashraf Fathy Said. "Mapping of Quantitative Trait Loci for Milk Yield Traits on Bovine Chromosome 5 in the Fleckvieh Cattle." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-126921.

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Conde-Martinez, F. Victor. "Quantitative trait loci and bulk segregant analysis to identify drought-related traits in maize (Zea mays L.)." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432430.

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Harilal, Vibin Eranezhath. "Genetics and Quantitative Trait Loci Mapping of Septoria Tritici Blotch Resistance, Agronomic, and Quality Traits in Wheat." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/26478.

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Most breeding programs aim at developing superior germplasm and better cultivars that combine high yield, disease and pest resistance, and end-use quality to satisfy the requirements of the growers as well as industry. A population, consisting of 138 F2-8 recombinant inbred lines (RILs) derived from a cross between ‘Steele-ND’ and ND 735, was evaluated to study the inheritance pattern of the septoria tritici blotch (STB)-resistant genes, agronomic and quality traits. The framework map made of 392 markers, including 28 simple sequence repeat (SSR) markers and 364 DArT markers, spanned a total distance of 1789.3 cM and consisted of 17 linkage groups. The map position of quantitative trait loci (QTL) found in this study coincided with the map position of durable STB resistance genes, Stb1. Thirteen QTL were detected for agronomic and quality traits. More saturation of the current map is needed to explore more QTL for this population.

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Yao, Ping. "Quantitative trait loci mapping and candidate gene analysis for growth and carcass traits on two bovine chromosomes." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4576.

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Thesis (M.S.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 7, 2009) Includes bibliographical references.

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Abdel-Haleem, Hussein Ahmed. "Genetics and mapping of quantitative trait loci of feed quality-related traits in barley (Hordeum vulgare L.)." Diss., Montana State University, 2005. http://etd.lib.montana.edu/etd/2004/abdel-haleem/Abdel-HaleemH0505.pdf.

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Bao, Haikun. "Bayesian hierarchical regression model to detect quantitative trait loci /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/baoh/haikunbao.pdf.

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Gong, Xiaohua. "Mapping Quantitative Trait Loci in Outbred Half-sib Populations." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-05042009-160015/.

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Quantitative trait loci (QTL) mapping in outbred populations faces some challenges unique to the divergent genetic background and complex pedigree relationships. Motivated by a dairy cattle half-sib data set from a grand daughter design, we present in this dissertation a series of endeavors to address various challenges along the analysis flow of QTL mapping. A first step is to infer the haplotypes in sires based on the observed genotypes in sires and his offspring. Our method was shown to outperform peer methods with greater robustness and accuracy yet with fast speed performance. Then in light of adapting the multiple interval mapping method to within-family QTL analysis, we extended the modeling framework by allowing for heteroscedastic residual variances and upgraded the Windows QTL Cartographer accordingly. The advantageous post-analysis result parsing from Windows QTL Cartographer and more importantly, the improved analysis outputs due to more powerful maximum likelihood-based mixture modeling than the least squares regression manifest our efforts in delivering better methodology via practically user friendly software. We further developed a mixed model approach for the purpose of QTL mapping across multiple families that was aimed at modeling QTL effects as both the fixed effect across families and the random effect within families. Our mixed model was shown to encompass similar or higher statistical testing performance on QTL variation than the widely used variance component modeling approach, yet still allowing permutations for obtaining chromosome-wide or genome-wide significance threshold. What's more, the flexibility of our mixed model in constructing alternative hypotheses testing on either fixed or random QTL effects or both was shown to offer interesting insight into the varying sources of signal that would not be unveiled by least squares regression or variance component methods. In concluding our comprehensive approach to QTL linkage mapping in dairy cattle populations, we continue to explore methods of fine mapping by combining both the linkage disequilibrium and linkage information and prospective method improvements are being sought.

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32

Marklund, Lena. "Genome analysis of quantitative trait loci in the pig /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1997. http://epsilon.slu.se/avh/1997/91-576-5416-6.gif.

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33

Ai, Ni, and 艾妮. "A novel framework for expression quantitative trait loci mapping." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B4715214X.

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Arloth, Janine. "Expression quantitative trait loci as possible biomarkers on depression." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-185767.

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35

Burns, Malcolm James. "Quantitative trait loci mapping in 'Arabidopsis' : theory and practice." Thesis, University of Birmingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405862.

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Nash, Nathan Wilkes. "Elucidation of quantitative trait loci for depression and anxiety." Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417280.

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Li, Jiahan. "Statistical model for mapping quantitative trait loci in autotetraploid." [Gainesville, Fla.] : University of Florida, 2008. http://purl.fcla.edu/fcla/etd/UFE0022877.

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Clarke, Jasper. "Quantitative trait locus mapping of oil yield and oil quality related traits in the biofuel crop Jatropha curcas." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/16007/.

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Jatropha curcas is a perennial shrub from the Euphorbiacea family. It is known for its stress resilience and high seed oil content, however little selective breeding has been carried out to fully domesticate this species. The aim of this project is to identify and map quantitative trait loci (QTL) for seed oil content, seed oil composition (oil quality), and oil yield, in order to identify loci suitable for introgression into an economically viable cultivar. In this study, an F2 population (G51xCV) consisting of 229 plants for linkage analysis, and 145 plants for QTL analysis, was used to identify and position 312 genetic markers and 8 quantitative traits onto a genetic linkage and QTL map. Over 288 short sequence repeat (SSR) markers were mined from genome sequence to complement single nucleotide polymorphism (SNP) markers from genomic and transcribed DNA. 132 of the mined SSRs were physically linked to candidate genes, leading to the mapping of a substantial portion of genes that form the seed oil biosynthetic pathway in Jatropha curcas. Integration of phenotypic datasets collected over 2 independent years, enabled the identification of 15 QTL regulating seed oil content (2QTL), seed oil composition; palmitate, stearate, oleate, linoleate content (10 QTL), seed weight (1 QTL), number of branches (1 QTL) and seed yield (1QTL). Combined PVE for these QTL accounted for between 9.34 % (palmitate content year 2) to 32.26 % (seed oil content Year 2) of observed variation. Analysis of final oil yield per plant, showed that seed yield (number of seeds) was most important for regulating oil yield in this mapping population, however seed oil content and seed weight were also important traits, highlighting that selection of both seed oil and vegetative traits are of utmost importance for optimising oil yield in Jatropha curcas.

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Darrah, Chiarina. "Quantitative trait locus analysis of circadian phase in Arabidopsis thaliana." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487036.

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The plant clock is the least well characterized of circadian systems, although mutant screens have identified a number of putative components. Here, an approach using forward genetics is employed which takes advantage of natural allelic variation in Arabidopsis thaliana ecotypes to identify areas ofgenome responsible for variation in clock traits. This means that intact, viable systems are the basis of analysis. Circadian output in transgenic seedlings is monitored by measuring the activity of a cab2::1uc+ transgene. The circadian parameter studied here is 'phase', i.e., the timing of a point of the circadian cycle relative to a fixed point in the external light dark cycle. The timing of the peak of cab2::1uc+ expression after last dawn was used as a phase marker. Initially, a quantitative trait locus ('QTL') analysis attempted to identify QTL for phase. Phase was measured in transgenic Arabidopsis seedlings from a population of recombinant inbred lines (Rll-s), whose genomes are homozygous mosaics derived from two inbred parental genotypes (Ler xCvi). QTL analysis attempts to correlate phenotypic variation with genetic variation within this population; both types of variation arise from the natural allelic variation present in the parents. The analysis was repeated on phase data obtained after entrainment to different photoperiods. Loci were found where Cvi alleles either advanced or delayed the phase relative to Ler alleles in particular environments. The QTL were characterized in near isogenic lines (t\lJLs). The Nll..,s are lines which contain small regions of Cvi alleles in an otherwise homogeneous Ler background, and the lines were transformed with cab2::1uc+ in order to measure their circadian output. This allowed us to evaluate candidates for genes underlying the QTL found.

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Smitchger, Jamin A. "Quantitative Trait Loci Associated with Lodging, Stem Strength, Yield, and Other Important Agronomic Traits in Dry Field Peas." Thesis, Montana State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10607937.

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In pea, lodging changes canopy structure, increases disease pressure, reduces yield, and reduces harvest efficiency. In order to discover the quantitative trait loci (QTLs) influencing lodging resistance and other important agronomic traits in pea, a recombinant inbred line (RIL) population was created from a relatively wide cross between the commercial variety Delta and an unnamed pea variety. The RIL population was grown for 6 site-years in Bozeman and Moccasin, MT, USA, and phenotypic data was collected for 22 quantitative morphological traits and seven categorical traits which were thought to be associated with lodging resistance. Genotypic data was derived from genotype by sequencing, microsattelite markers, and cleaved amplified sequence tagged sites.

QTL analysis identified a total of 135 putative QTLs for the 22 traits examined in the study. There were 12 specific regions where 115 QTLs co-located, indicating that as few as 12 genes may be responsible for multiple pleiotropic effects. Ten QTLs were found for lodging resistance. Due to the large amount of phenotypic data collected, the putative mechanism of lodging resistance was determined for each QTL. In nearly every case, lodging resistance was associated with reduced plant height, a change in tendril number, or increased stem strength. This conclusion was supported by mathematical modeling. Branch number, which determines the number of tendrils per plant, was also positively associated with lodging resistance during all site-years, indicating that increasing tendril number also increases lodging resistance.

Yield was controlled by eight QTLs. All QTLs for yield had pleiotropic effects on lodging resistance and yield per plant. Seed size was not correlated with yield, and a model was created which explained why no association between yield and seed size was found.

The pleiotropic effects and utility of the QTLs discovered in this study are discussed. The results of this study further refine the ideotype for pea, and can be used for marker assisted selection in this crop.

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Kunert, Antje [Verfasser]. "Quantitative trait loci for agronomic and quality traits in two advanced backcross populations of winter wheat / Antje Kunert." Aachen : Shaker, 2007. http://d-nb.info/1170528260/34.

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42

Silva, Heyder Diniz. "Aspectos biométricos da detecção de QTL'S ("Quantitative Trait Loci") em espécies cultivadas." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/11/11134/tde-18102002-162652/.

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O mapeamento de QTL's difere dos demais tipos de pesquisas conduzida em genética. Por se tratar basicamente de um procedimento de testes múltiplos, surge, neste contexto, um problema que se refere ao nível de significância conjunto da análise, e consequentemente, seu poder. Deste modo, avaliou-se, via simulação computacional de dados, o poder de detecção de QTL's da análise de marcas simples, realizada por meio de regressão linear múltipla, utilizando o procedimento stepwise" para seleção das marcas e procedimentos baseados em testes individuais, utilizando os critérios FDR e de Bonferroni para determinação nível de significância conjunto. Os resultados mostraram que o procedimento baseado em regressão múltipla, utilizando o procedimento stepwise" foi mais poderoso em identificar as marcas associadas a QTL's e, mesmo nos casos em que este procedimento apresentou poder ligeiramente inferior aos demais, verificou-se que o mesmo tem como grande vantagem selecionar apenas as marcas mais fortemente ligadas aos QTL's. Dentre os critérios FDR e de Bonferroni, o primeiro mostrou-se, em geral, mais poderoso, devendo ser adotado nos procedimentos de mapeamento por intervalo. Outro problema encontrado na análise de QTL's refere-se µa abordagem da interação QTL's x ambientes. Neste contexto, apresentou-se uma partição da variância da interação genótipos x ambientes em efeitos explicados pelos marcadores e desvios, a partir da qual obtiveram-se os estimadores da proporção da variância genética (pm), e da variância da interação genótipos x ambientes (pms), explicadas pelos marcadores moleculares. Estes estimadores independem de desvios das frequências alélicas dos marcadores em relação µ as esperadas (1:2:1 em uma geração F2, 1:1 em um retrocruzamento, etc.), porém, apresentam uma alta probabilidade de obtenção de estimativas fora do intervalo paramétrico, principalmente para valores elevados destas proporções. Contudo, estas probabilidades podem ser reduzidas com o aumento do número de repetições e/ou de ambientes nos quais as progênies são avaliadas. A partir de um conjunto de dados de produtividade de grãos, referentes µ a avaliação de 68 progênies de milho, genotipadas para 77 marcadores moleculares codominantes e avaliadas em quatro ambientes, verificou-se que as metodologias apresentadas permitiram estimar as proporções pm e pms, bem como classificar as marcas associadas a QTL's, conforme seu nível de interação. O procedimento permitiu ainda a identificação de regiões cromossômicas envolvidas no controle genético do caractere sob estudo conforme sua maior ou menor estabilidade ao longo dos ambientes.
In general terms, QTL mapping di®ers from other research ac-tivities in genetics. Being basically a multiple test procedure, problems arise which are related to the joint level of signi¯cance of the analysis, and consequently, to its power. Using computational simulation of data, the power of simple marker analysis, carried out through multiple linear regression, using stepwise procedures to select the markers was obtained. Procedures based on single tests, using both the FDR and the Bonferroni criteria to determinate the joint level of signi¯cance were also used. Results showed that the procedure based on multiple regression, using the stepwise technique, was the most powerful in identifying markers associated to QTL's. However, in cases where its power was smaller, its advantage was the ability to detect only markers strongly associates with QTL's. In comparision with the Bonferroni method, the FDR criterion was in general more powerful, and should be adopted in the interval mapping procedures. Additional problems found in the QTL analysis refer to the QTL x environment interaction. We consider this aspect by par-titioning the genotype x environment interaction variance in components explained by the molecular markers and deviations. This alowed estimating the proportion of the genetic variance (pm), and genotype x environment variance (pms), explained by the markers. These estimators are not a®ected by deviations of allelic frequencies of the markers in relation to the expected values (1:2:1 in a F2 generation, 1:1 in a backcross , etc). However, there is a high probability of obtaining estimates out of the parametric range, specially for high values of this proportion. Nevertheless, these probabilities can be reduced by increasing the number of replications and/or environments where the progenies are evaluated. Based on a set of grain yield data, obtained from the evaluation of 68 maize progenies genotyped for 77 codominant molecular markers, and evaluated as top crosses in four environments, the presented methodologies allowed estimating proportions pm and pms as well the classification of markers associated to QTL's, with respect to its level of genotype x environment interaction. The procedure also allowed the identification of chromosomic regions, involved in the genetical control of the considered trait, according to its stability, in relation to the observed environmental variation.

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43

Li, Jingzhao. "Mapping of new microsatellite markers and molecular identification of quantitative trait locus (QTL) for agronomically important traits in barley." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97412141X.

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44

Jung, Jeesun. "High resolution linkage and association study of quantitative trait loci." Texas A&M University, 2004. http://hdl.handle.net/1969.1/2681.

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As a large number of single nucleotide polymorphisms (SNPs) and microsatellite markers are available, high resolution mapping employing multiple markers or multiple allele markers is an important step to identify quantitative trait locus (QTL) of complex human disease. For many complex diseases, quantitative phenotype values contain more information than dichotomous traits do. Much research has been done on conducting high resolution mapping using information of linkage and linkage disequilibrium. The most commonly employed approaches for mapping QTL are pedigree-based linkage analysis and population-based association analysis. As one of the methods dealing with multiple alleles markers, mixed models are developed to work out family-based association study with the information of transmitted allele and nontransmitted allele from one parent to offspring. For multiple markers, variance component models are proposed to perform association study and linkage analysis simultaneously. Linkage analysis provides suggestive linkage based on a broad chromosome region and is robust to population admixtures. One the other hand, allelic association due to linkage disequilibrium (LD) usually operates over very short genetic distance, but is affected by population stratification. Combining both approaches plays a synergistic role in overcoming their limitations and in increasing the efficiency and effectiveness of gene mapping.

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45

Pearson, Caroline. "Analysis of a hierarchial Bayesian method for quantitative trait loci /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-2/pearsonc/carolinepearson.pdf.

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46

Purcell, Shaun. "Sample selection and complex effects in quantitative trait loci analysis." Thesis, King's College London (University of London), 2003. https://kclpure.kcl.ac.uk/portal/en/theses/sample-selection-and-complex-effects-in-quantitative-trait-loci-analysis(730a92fb-113b-42c1-8f38-8a085bb37112).html.

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47

Zhou, Hua, Jin Zhou, Eric Sobel, and Kenneth Lange. "Fast genome-wide pedigree quantitative trait loci analysis using MENDEL." BioMed Central, 2014. http://hdl.handle.net/10150/610091.

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The linkage era left a rich legacy of pedigree samples that can be used for modern genome-wide association sequencing (GWAS) or next-generation sequencing (NGS) studies. Family designs are naturally equipped to detect rare variants, control for population stratification, and facilitate the study of parent-of-origin effects. Unfortunately, pedigree likelihoods are notoriously hard to compute, and current software for association mapping in pedigrees is prohibitively slow in processing dense marker maps. In a recent release of the comprehensive genetic analysis software MENDEL, we implemented an ultra-fast score test for association mapping with pedigree-based GWAS or NGS study data. Our implementation (a) works for random sample data, pedigree data, or a mix of both
(b) allows for covariate adjustment, including correction for population stratification
(c) accommodates both univariate and multivariate quantitative traits
and (d) allows missing values in multivariate traits. In this paper, we assess the capabilities of MENDEL on the Genetic Analysis Workshop 18 sequencing data. For instance, when jointly testing the 4 longitudinally measured diastolic blood pressure traits, it takes MENDEL less than 51 minutes on a standard laptop computer to read, quality check, and analyze a data set with 959 individuals and 8.3 million single-nucleotide polymorphisms (SNPs). Our analysis reveals association of one SNP in the q32.2 region of chromosome 1. MENDEL is freely available on http://www.genetics.ucla.edu/software webcite.

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Harenza, Jo Lynne. "Genetic Dissection of Quantitative Trait Loci for Substances of Abuse." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3190.

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It has been reported that an individual’s initial level of response to a drug might be predictive of his or her future risk of becoming dependent, thus basal gene expression profiles underlying those drug responses may be informative for both predicting addiction susceptibility and determining targets for intervention. This dissertation research aims to elucidate genetic risk factors underlying acute alcohol and nicotine dependence phenotypes using mouse genetic models of addiction. Phenotyping, brain region-specific mRNA expression profiling, and genetic mapping of a recombinant inbred panel of over 25 mouse strains were performed in order to identify quantitative trait loci (QTL) harboring candidate genes that may modulate these phenotypes. Previous BXD (B6 x D2) behavioral studies performed in our laboratory identified an ethanol-induced anxiolysis-like QTL (Etanq1) in the light dark box (LDB). We hypothesized that genetic variation within Nin (a gene within the Etanq1 support interval involved in microtubule-anchoring) may modulate anxiolytic-like responses to acute ethanol in the LDB as well as other preclinical models of anxiety, the elevated plus maze (EPM), and marble burying (MB) task. Molecular studies have allowed us to confirm cis regulation of Nin transcript levels in the NAc. To elucidate potential mechanisms mediating Etanq1, the pharmacological tools, diazepam and HZ166 (a benzodiazepine derivative) were utilized to interrogate whether GABAA receptor activation modulates ethanol’s anxiety-like behaviors in the LDB. We show that the LDB phenotype, percent time spent (PTS) in the light following a brief restraint stress, is not being modulated through direct activation of GABAA α2/α3 receptor subunits. To genetically dissect Etanq1 as well as parse the ethanol anxiolytic-like phenotype, we have assayed 8 inbred strains, selected based on genotypes at Nin, in various preclinical models of anxiety. Principal components analysis of these behavioral data suggests that the gene(s) modulating the ethanol anxiolytic-like component in the LDB do not overlap with similar phenotypes in the elevated plus maze (EPM), nor the MB phenotype. Furthermore, site-specific delivery of an sh-Nin lentivirus into the NAc of D2 mice revealed that Nin may modulate one LDB endophenotype, latency to enter the light side of the LDB, which loaded as a part of the “anxiolysis” principal component. These data strongly imply that basal neuronal Nin expression in the NAc is important for acute ethanol anxiolytic-like behavior, perhaps through a novel mechanism involving synaptic remodeling. In separate behavioral QTL mapping studies, we hypothesized that genetic variation regulating expression of Chrna7 modulates the reward-like phenotype, conditioned place preference (CPP), for nicotine. We provide evidence for genetic regulation of Chrna7 across the BXD panel of mice and through pharmacological and genetic behavioral studies, confirm Chrna7 as a quantitative trait gene modulating CPP for nicotine in mice. Microarrays, followed by network analyses, allowed us to identify a genetically co-regulated network within the nucleus accumbens (NAc), differentially expressed in mice null for Chrna7, which was similarly correlated in the BXD panel of mice. Our network and molecular analyses suggest a putative role for Chrna7 in regulating insulin signaling in the NAc, which together, may contribute to the enhanced sensitivity to nicotine observed in strains of mice that lack or have low mRNA levels of Chrna7 in the NAc. Overall, this research has elucidated and confirmed new genetic risk factors underlying alcohol and nicotine dependence phenotypes and has enabled a better understanding of the neurogenomic bases of alcohol and nicotine addiction. Future studies that further investigate the signaling pathways and/or gene interactions involving Nin and Chrna7 may lead the field to new candidates for pharmacotherapies that may be tailored for use in individuals with susceptible genotypes. Supported by NIAAA grants P20AA017828 and R01AA020634 to MFM, NIDA T32DA007027 to WLD, and NIDA R01DA032246 to MFM and MID.

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Li, Dan. "Using quantitative trait locus mapping to understand arsenite tolerance in Arabidopsis." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720646.

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Indian mustard (Brassica juncea) grown on land with elevated arsenic concentration can absorb and accumulate high levels of arsenic. B. juncea is an important oil-bearing crop and broadly grown in Bangladesh and West Bengal, where the land is heavily contaminated with arsenic. Arsenic is documented as a group 1 carcinogen and can enter the biosphere through the food chain. With the high population density and a heavy agriculture-based economy in Bangladesh and West Bengal, issues related to food safety must be addressed to solve the problems associated with arsenic accumulation in B. juncea seed oil, which is caused by B. juncea tolerance to arsenic toxicity. Therefore, it is important to study the variation of arsenic tolerance among different Indian mustard cultivars and to understand the genetic mechanisms of arsenic tolerance in Indian mustard. Such results from the study could help to reduce potential arsenic toxicity in both plants and humans through diet as well as to benefit local agriculture industry in Bangladesh and West Bengal. In this research, a consistent trend was found between arsenic concentration and biomass accumulation in all B. juncea cultivars. When arsenic concentration increases, the biomass accumulation decreases. A positive correlation was identified between arsenic tolerance levels in B. juncea roots and arsenic absorption in the seed and seed oil. The observation of these correlations in B. juncea suggests that breeding arsenic resistant B. juncea cultivars could increase plant yield but may inadvertently lead to an increased arsenic concentrations in the seed and seed oil. However, variations in arsenic accumulation were observed in both arsenic resistant and susceptible cultivars, which provide possibilities to breed high arsenic-tolerant and low arsenic-absorptive strains of B. juncea. To study the genetic mechanisms underlying arsenic tolerance variation in Indian mustard, the model plant Arabidopsis thaliana was employed. Arsenic tolerance of various A. thaliana accessions was measured and arsenic tolerance genes were screened using a genetic mapping approach. Since no consistent trend was found between arsenic concentrations and arsenic tolerance in A. thaliana root and shoot tissues, it suggests that arsenic has a complex impact on those phenotypes examined in A. thaliana. To study the mechanisms underlying genetic variation of A. thaliana for arsenic tolerance, gene mapping including quantitative trait locus (QTL) mapping and genome-wide association mapping (GWAS) was employed to identify targeted genomic regions and candidate genes. One recombined inbred population was employed in QTL mapping and a worldwide collection of 39 A. thaliana accessions was used in GWAS analysis. QTL mapping analysis and GWAS revealed similar genomic regions and candidate genes. Among all revealed candidate genes, one gene (gene ID: At5G05560) with a known function of abiotic stress resistance was identified, which may be related to plant arsenic tolerance or detoxification. To understand the function of this gene, however, requires further analysis. Other genes associated with arsenic tolerance or detoxification function in the genetic region selected from gene mapping study may also be identified by further analysis. The functional analysis of candidate genes, and the molecular markers selection from revealed genomic regions could be applied to contribute to breeding B. juncea strains with higher arsenic tolerance and lower arsenic accumulation.

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50

Boddhireddy, Prashanth. "Development of highly recombinant inbred populations for quantitative-trait locus mapping." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1671.

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Dissertations / Theses on the topic 'Quantitative trait locis'

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