My dissertation research investigates the genetic architecture and evolutionary significance of physiological variation in two wildflower species, Ipomopsis aggregata and Arabidopsis thaliana. In particular, my work focuses on water use efficiency (WUE), a critical physiological trait that dictates plant growth and performance in resource-limited environments. I used a combination of quantitative trait loci (QTL) mapping, field selection experiments, and classic quantitative genetics to investigate 1) the genetic architecture of water use efficiency and flowering time, 2) patterns of natural selection on water use efficiency, flowering time, and other ecological traits in I. aggregata, and 3) additive genetic variation, genetic correlations, and selection on water use efficiency, flowering time, and plasticity to drought in Arabidopsis thaliana. Using an Ipomopsis aggregata genetic mapping population, I identified four QTL underlying WUE, three QTL-QTL epistatic interactions, and evidence for a possible QTL x cytoplasmic interaction affecting WUE. I found a similar genetic architecture underlying flowering time, with four main effect QTLs that all adjacently localized to the same linkage groups as WUE, and three QTL-QTL epistatic interactions, which occur between the same chromosome pairs as the WUE interactions. The combined main and interactive effects explain 35% and 40% of the phenotypic variation in WUE and flowering time, respectively. The adjacent localization suggests a possible role for the evolution of co-inheritance or, if the true QTL positions actually overlap, a possible role for pleiotropy underlying the phenotypic correlation between WUE and flowering time. Additionally, these results suggest epistasis is a significant factor affecting phenotypic variation in nature. In a reciprocal transplant and water addition experiment, I demonstrated variable natural selection on WUE, flowering time, and nectar production in I. aggregata across elevation/habitat and differential water availability. At low elevation in the water addition treatment, natural selection favors early flowering and greater nectar sugar concentration, while dry conditions favor high WUE and early flowering time. At high elevation, where the growing season is shorter and drier, selection favors early flowering regardless of water addition. These results suggest natural selection on ecophysiological and floral traits varies with resource availability (e.g. water availability and pollinator visitation). Using data from a glasshouse experiment involving a global panel of accessions of Arabidopsis thaliana, I demonstrated strong positive genetic correlation between WUE and flowering time, as well as selection for low WUE and early flowering under experimental season-ending drought. Finally, I found significant genetic variation in plasticity as well as selection favoring greater WUE plasticity under drought, indicating plasticity to drought is adaptive in A. thaliana. / text

Mapping quantitative trait loci (QTL) for traits under consideration for genetic improvement is becoming more common for many aquatic species, including Atlantic salmon. The objective of the study was to map QTL associated with length, weight, shape, parr mark number and contrast in three F2 hybrid families of European and North American strains of Atlantic salmon using single nucleotide polymorphisms. GridQTL software was used to perform separate analyses for male and female linkage maps. Numerous highly significant QTL were detected for every trait. Locations of QTL differed based on age and map used. Some QTL locations for the analyzed traits were similar to those of other studies on purebred and backcross Atlantic salmon populations; however, many more QTL were detected in the hybrid F2’s. The amount of genetic variation in skin colour and pattern displayed within the transAtlantic F2 families greatly exceeded the ranges seen in nature. / NSERC Strategic Grant

The existence of new technologies, implemented in efficient platforms and workflows has made massive genotyping available to all fields of biology and medicine. Genetic analyses are no longer dominated by experimental work in laboratories, but rather the interpretation of the resulting data. When billions of data points representing thousands of individuals are available, efficient computational tools are required. The focus of this thesis is on developing models, methods and implementations for such tools. The first theme of the thesis is multi-dimensional scans for quantitative trait loci (QTL) in experimental crosses. By mating individuals from different lines, it is possible to gather data that can be used to pinpoint the genetic variation that influences specific traits to specific genome loci. However, it is natural to expect multiple genes influencing a single trait to interact. The thesis discusses model structure and model selection, giving new insight regarding under what conditions orthogonal models can be devised. The thesis also presents a new optimization method for efficiently and accurately locating QTL, and performing the permuted data searches needed for significance testing. This method has been implemented in a software package that can seamlessly perform the searches on grid computing infrastructures. The other theme in the thesis is the development of adapted optimization schemes for using hidden Markov models in tracing allele inheritance pathways, and specifically inferring haplotypes. The advances presented form the basis for more accurate and non-biased line origin probabilities in experimental crosses, especially multi-generational ones. We show that the new tools are able to reconstruct haplotypes and even genotypes in founder individuals and offspring alike, based on only unordered offspring genotypes. The tools can also handle larger populations than competing methods, resolving inheritance pathways and phase in much larger and more complex populations. Finally, the methods presented are also applicable to datasets where individual relationships are not known, which is frequently the case in human genetics studies. One immediate application for this would be improved accuracy for imputation of SNP markers within genome-wide association studies (GWAS). / eSSENCE

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Made available in DSpace on 2015-03-26T13:42:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 365530 bytes, checksum: 14eb9333accf37cc0f88b5dbb33077f0 (MD5) Previous issue date: 2008-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Molecular markers can be used to identify chromosomal regions harboring quantitative trait locos (QTL) that control traits of economic importance in farm animals. To study these locos in the pig, a resource population has been generated from a cross between two Naturalized Brazilian Piau grand sires and eighteen Commercial grand dams (Landrace x Large White x Piétrain). A total of 614 F2 progeny from 50 matings of F1 parents were produced. Phenotypic data on performance, carcass, internal organs, viscera, carcass cuts and meat quality traits were collected on the F2 animals. Parentals, F1 e F2 animals were genotyped for 17 microsatellite markers covering the chromosomes 5, 7 e 8. The loci were considered appropriate for quantitative analysis, when it was analysed their values for observed heterogosity (Ho), expected heterozigosity (He) and polimorfic information content (PIC). In the chromosome 5, the average values of the Ho, He; and PIC found were 0,73; 0,66 and 0,61; in the chromosome 7, the values found were 0,81, 071 and 0,67 and in the chromosome 8 had the average values for Ho, He and PIC of 0,65; 0,65 and 0,61 respectively. After the genotype scoring, it was constructed the linkage map for these markers in the population. Association analyses were performed using interval mapping by regression for QTL detection. Seventeen QTL were mapped for carcass and cuts carcass traits on the three chromosomes, while just one QTL for feed intake were found for performance trait in the eight chromosome. One QTL for Total (bone-in) loin weight (Kg) and for bacon depth were mapped and not yet described in the literature on the seven chromosome. The generated information of significant QTL will be useful for future studies dealing fine mapping with and identification of genes that could provide a better understanding of physiology and production traits of pigs. / Marcadores moleculares podem ser usados para identificar regiões cromossômicas que contêm locos de características quantitativas (QTL) que controlam fenótipos de importância econômica em animais de produção. Para estudá-los em suínos, foi gerada uma população de um cruzamento entre dois varrões da raça naturalizada Piau e dezoito fêmeas da linha comercial (Landrace x Large White x Pietrain). Uma progênie de 614 animais na F2 foi produzida de 50 acasalamentos da F1. Os dados fenotípicos de desempenho, carcaça, órgãos internos, vísceras, corte de carcaça e qualidade de carne foram coletados nos animais F2. Os animais parentais, F1 e F2 foram genotipados para 17 marcadores tipo microssatélites cobrindo os cromossomos 5, 7 e 8. Os locos foram considerados adequados para estudos de características quantitativas, quando foram analisados os valores de heterozigosidade observada (Ho), heterozigosidade esperada (He) e conteúdo de informação polimórfica (PIC). No cromossomo 5, os valores das médias de Ho, He e PIC encontrados foram 0,73; 0,66 e 0,61; no cromossomo 7, os valores encontrados foram 0,81, 071 e 0,67 e no cromossomo 8 os valores foram 0,65; 0,65 e 0,61. Com o resultado da genotipagem foi construído o mapa de ligação específico dos marcadores para a população desenvolvida. As análises de associação foram feitas utilizando mapeamento por intervalo por regressão para detecção de QTL. Foram detectados 17 QTL para características de carcaça e corte de carcaça nos três cromossomos, enquanto para característica de desempenho apenas um QTL para conversão alimentar foi encontrado no cromossomo oito. Não foram encontrados nas literaturas consultadas QTL para Peso de Carré e Espessura de Bacon no cromossomo sete. As informações dos QTL significativos encontrados servem para estudos futuros como o mapeamento fino e identificação de genes que ajudam no melhor entendimento da fisiologia e características de produção de suínos.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O conhecimento sobre os parÃmetros genÃticos, a identificaÃÃo de locos de caracterÃsticas quantitativas (QTL) e a seleÃÃo assistida por marcadores tÃm grande importÃncia para o melhoramento genÃtico vegetal. Objetivou-se com o presente estudo avaliar o potencial de produÃÃo de oitenta e quatro clones de cajueiro, estimar parÃmetros genÃticos e identificar QTLs associados à altura da planta, diÃmetro da copa, antracnose, mofo-preto, nÃmero de flores hermafroditas/panÃcula e peso da castanha. Considerando estes objetivos, dois experimentos foram conduzidos em dois locais (Pacajus e Paraipaba), no estado do CearÃ, Brasil. Os experimentos foram conduzidos em delineamento de blocos casualizados com duas repetiÃÃes e duas plantas por parcela. As caracterÃsticas foram avaliadas nos anos 2009, 2010 e 2011. A identificaÃÃo dos QTLs candidatos foi realizada utilizando os mÃtodos de mapeamento nÃo-paramÃtrico, mapeamento por intervalo e mapeamento de QTLs mÃltiplos. Os resultados permitem observar apresenÃa de variabilidade genotÃpica na geraÃÃo F1 para todos os caracteres avaliados, com alto potencial para seleÃÃo de genÃtipos superiores, com resistÃncia à antracnose e ao mofo-preto, altas produÃÃes de flor hermafrodita/panÃcula e de castanha. Os clones da geraÃÃo F1: 1, 16, 17, 41, 57, 65, 76 e 78 foram considerados os mais promissores para as caracterÃsticas analisadas. A anÃlise conjunta indicou a presenÃa de interaÃÃo genÃtipo x ambiente para todas as caracterÃsticas estudadas. Hà presenÃa de QTLs para todos os caracteres avaliados, explicando entre 2,16% a 19,47% da variaÃÃo fenotÃpica total nos caracteres diÃmetro de copa e flores hermafroditas, respectivamente. As anÃlises de QTL ao longo dos anos e locais revelaram efeitos importantes da interaÃÃo genÃtipo x ambiente na detecÃÃo de QTL. Este resultado concorda com as diferenÃas encontradas na mÃdia das caracterÃsticas ao longo dos anos e locais, estando relacionada, entre outras causas, à alternÃncia de alguns clones (genÃtipos) para as caracterÃsticas analisadas e a quantidade de chuva por ambiente. / Knowledge about genetic parameters, identification of quantitative trait loci (QTL) and marker-assisted selection have great interest for genetic improvement. The objectives of this research were to evaluate the yield potential of eighty four clones of cashew, to estimate their genetic parameters and to identify QTLs associated with plant height, canopy diameter, anthracnose, black mold, number of hermaphrodite flower/panicle and nut weight. Considering these objectives, two trials were planted in two different countries (PacajÃs and Paraipaba), state of CearÃ, Brazil. The experimental phase was conducted in a randomized block design with two replications, two plants per plot. Apart the traits were evaluated during years 2009, 2010 and 2011. Detection of candidate QTLs were realized using the methods non-parametric mapping, interval mapping and multiple QTL mapping. The evidence of genotypic variability was detected in F1 generation to all characters analyzed. The high potential for the selection of genotypes with the best characteristics to resistance to anthracnose and black mold, hermaphrodite flower and yield. The generation F1 clones named as: 1, 16, 17, 41, 57, 65, 76 and 78 were considered the most promising materials for breeding propose. The joint analysis indicated significant genotype by environment interaction for all traits studied. QTLs for traits of agronomic importance were identified with potential for marker-assisted selection. There is presence of QTLs for all traits, explaining between 2.16 to 19.47% of the total phenotypic variation in the traits canopy diameter and hermaphrodite flowers, respectively. QTL analysis over years and places revealed important effects of genotype by environment interaction on QTL detection. This result agrees with the differences found for the average trait among years and places related, among other causes, the alternation of some clones (genotypes) for traits analyzed and the amount of rain for the environment.

Camundongos foram selecionados geneticamente para alta (AIRmax) ou baixa (AIRmin) resposta inflamatória aguda, sendo utilizados em experimentos de regeneração tecidual. Foi observado que AIRmax apresentam uma regeneração rápida do tecido da orelha em relação aos AIRmin, sugerindo a existência de loci reguladores comuns para ambos fenótipos de inflamação e regeneração do tecido. Neste estudo investigamos o fenótipo inflamatório e o perfil de expressão gênica global em AIRmax e AIRmin durante a fase inicial da regeneração do tecido da orelha. A análise histológica mostrou que AIRmax apresentam uma regeneração completa, com formação de ilhas de cartilagem e glândulas sebáceas no centro da área regenerada. Os AIRmin não apresentam regeneração. Os dados obtidos sobre edema de orelha e níveis de MPO foram maiores em AIRmax quando comparados com AIRmin (P <0,001). A análise de expressão gênica global mostrou 794 genes ativados e 528 genes reprimidos em AIRmax, enquanto 1.086 genes ativados e 1.145 genes reprimidos nos AIRmin, 48 horas após a lesão. AIRmax e AIRmin apresentaram alta modulação de genes sobrerrepresentados em temas biológicos para resposta inflamatória, adesão celular e quimiotaxia (Gene Ontology). No entanto, foi observado uma baixa modulação de genes sobrerrepresentados para o transporte em AIRmax e para taxia, contração muscular e ciclo de ubiquitina em AIRmin. Nas regiões próximas ao QTL anteriormente encontrado no cromossomo 1, foram observados genes diferencialmente expressos como Stat1, Casp8, Hspe1 e Il1r2, enquanto Lect1, Fndc3 e Egr3 foram detectados no cromossomo 14. Os experimentos com qPCR mostram uma alta expressão de Il-1<font face=\"Symbol\">b, Il-8rb e Mmp9 em AIRmax e Cxcl2, Tnfa e Tgfb em AIRmin. Concluímos que os animais AIRmax e AIRmin apresentam (nos cromossomos 1 e 14) genes inflamatórios diferencialmente expressos que podem estar envolvidos nos fenótipos de resposta inflamatória aguda e regeneração do tecido da orelha. / Mice selected for high (AIRmax) or low (AIRmin) acute inflammatory response were used in tissue regeneration experiments. It was observed that AIRmax present faster ear tissue regeneration than AIRmin mice, suggesting the involvement of common regulatory loci for both inflammation and ear tissue regeneration phenotypes. In the study we investigated some inflammatory phenotypes and global gene expression profiles in AIRmax and AIRmin mice during the initial phase of the ear tissue regeneration. The histological analyses showed that AIRmax regeneration was complete, and cartilage islands and sebaceous glands were formed in the middle of the regenerated area. AIRmin mice displayed not regeneration. Ear thickness oedema and MPO levels were higher in AIRmax than AIRmin mice (P< 0.001). Global expression analysis showed 794 activated and 528 repressed genes in AIRmax, while 1086 activated and 1145 repressed genes were observed in AIRmin mice 48 hours after injury. AIRmax and AIRmin mice presented up-regulated genes over-represented in inflammatory response, cell adhesion and chemotaxis biological themes (Gene ontology). However, down-modulated genes were significant over-represented for transportation in AIRmax and for taxis, muscle contraction and cycle ubiquitin in AIRmin mice. In the previously QTL regions detected on chromosome 1 differentially-expressed Stat1, Casp8, Hspe1 and Il1r2 genes were found, while Lect1, Fndc3 and Egr3 were detected on chromosome 14. qPCR experiments showed high expression of Il-1<font face=\"Symbol\">b, Il-8rb and Mmp9 in AIRmax and Cxcl2, Tnfa, and Tgfb1 in AIRmin mice. We conclude that AIRmax and AIRmin mice presented several (some on chromosomes 1 and 14) differentially-expressed inflammatory genes which could be involved in the acute inflammatory response and ear tissue regeneration phenotypes.

A produção de grãos e outros caracteres de importância econômica para a cultura do milho, tais como a altura da planta, o comprimento e o diâmetro da espiga, apresentam herança poligênica, o que dificulta a obtenção de informações sobre as bases genéticas envolvidas na variação desses caracteres. Associações entre marcadores e QTLs foram analisadas através dos métodos de mapeamento por intervalo composto (CIM) e mapeamento por intervalo Bayesiano (BIM). A partir de um conjunto de dados de produção de grãos, referentes à avaliação de 256 progênies de milho genotipadas para 139 marcadores moleculares codominantes, verificou-se que as metodologias apresentadas permitiram classificar marcas associadas a QTLs. Através do procedimento CIM, associações entre marcadores e QTLs foram consideradas significativas quando o valor da estatística de razão de verossimilhança (LR) ao longo do cromossomo atingiu o valor máximo dentre os que ultrapassaram o limite crítico LR = 11; 5 no intervalo considerado. Dez QTLs foram mapeados distribuídos em três cromossomos. Juntos, explicaram 19,86% da variância genética. Os tipos de interação alélica predominantes foram de dominância parcial (quatro QTLs) e dominância completa (três QTLs). O grau médio de dominância calculado foi de 1,12, indicando grau médio de dominância completa. Grande parte dos alelos favoráveis ao caráter foram provenientes da linhagem parental L0202D, que apresentou mais elevada produção de grãos. Adotando-se a abordagem Bayesiana, foram implementados métodos de amostragem através de cadeias de Markov (MCMC), para obtenção de uma amostra da distribuição a posteriori dos parâmetros de interesse, incorporando as crenças e incertezas a priori. Resumos sobre as localizações dos QTLs e seus efeitos aditivo e de dominância foram obtidos. Métodos MCMC com saltos reversíveis (RJMCMC) foram utilizados para a análise Bayesiana e Fator calculado de Bayes para estimar o número de QTLs. Através do método BIM associações entre marcadores e QTLs foram consideradas significativas em quatro cromossomos, com um total de cinco QTLs mapeados. Juntos, esses QTLs explicaram 13,06% da variância genética. A maior parte dos alelos favoráveis ao caráter também foram provenientes da linhagem parental L02-02D. / Grain yield and other important economic traits in maize, such as plant heigth, stalk length, and stalk diameter, exhibit polygenic inheritance, making dificult information achievement about the genetic bases related to the variation of these traits. The number and sites of (QTLs) loci that control grain yield in maize have been estimated. Associations between markers and QTLs were undertaken by composite interval mapping (CIM) and Bayesian interval mapping (BIM). Based on a set of grain yield data, obtained from the evaluation of 256 maize progenies genotyped for 139 codominant molecular markers, the presented methodologies allowed classification of markers associated to QTLs.Through composite interval mapping were significant when value of likelihood ratio (LR) throughout the chromosome surpassed LR = 11; 5. Significant associations between markers and QTLs were obtained in three chromosomes, ten QTLs has been mapped, which explained 19; 86% of genetic variation. Predominant genetic action for mapped QTLs was partial dominance and (four QTLs) complete dominance (tree QTLs). Average dominance amounted to 1,12 and confirmed complete dominance for grain yield. Most alleles that contributed positively in trait came from parental strain L0202D. The latter had the highest yield rate. Adopting a Bayesian approach to inference, usually implemented via Markov chain Monte Carlo (MCMC). The output of a Bayesian analysis is a posterior distribution on the parameters, fully incorporating prior beliefs and parameter uncertainty. Reversible Jump MCMC (RJMCMC) is used in this work. Bayes Factor is used to estimate the number of QTL. Through Bayesian interval, significant associations between markers and QTLs were obtained in four chromosomes and five QTLs has been mapped, which explained 13; 06% of genetic variation. Most alleles that contributed positively in trait came from parental strain L02-02D. The latter had the highest yield rate.

Camundongos AIRmax e AIRmin homozigotos para os alelos R e S do gene Slc11a1 foram avaliados para susceptibilidade à artrite induzida por pristane (PIA). A presença do alelo S aumentou a incidência e a gravidade nos AIRmax, sugerindo que o gene Slc11a1, ou outro próximo, esteja interagindo com os loci de resposta inflamatória na modulação de PIA. Para identificar estes loci foram realizados estudos de associação genótipo-fenótipo e de expressão gênica global. Os RNAs das patas dos animais foram isolados após 180 dias da indução por pristane. As análises de expressão gênica global foram realizadas usando a plataforma Codelink (36k genes), cujos resultados foram validados por PCR em tempo real. Os estudos de associação foram realizados através da análise de polimorfismo de microssatélites pelo programa MapManager. Foram identificadas duas regiões nos cromossomos 1 e 11. Um número grande de genes diferencialmente expressos foi verificado nos animais AIRmax SS cujos temas biológicos significativamente sobre-representados foram a resposta inflamatória e quimiotaxia. Os camundongos AIRmax SS também possuem uma ativação maior dos genes Ccl3, Ccl7, C3ar1, Il10, Stat3, Tirap, Trem 1, Trem 3, Mefv, Ptx3, Chi3l3 e Kras. Alguns desses genes co-localizam com regiões previamente mapeadas nos cromossomos 1 e 11. / AIRmax and AIRmin mice homozygous for Slc11a1 R and S allele were evaluated for pristane-induced arthritis (PIA) susceptibility. The presence of S allele increased the incidence and the arthritis severity in ARmax mice, suggesting that Slc11a1 or other closed-linked gene interacts with inflammatory loci to modulate PIA. In order to identify inflammatory modifier loci modulating experimental arthritis development, genotype-phenotype association studies and global gene expression analyses were performed. Mice received i.p. injections of pristane and the paw RNAs were isolated at day 180. Global gene expression analysis was performed on Codelink bioarrays (36k genes) and validated by real time PCR. The microsatellite polymorphism analyses were performed using MapManager program. Two regions on chromosomes 1 and 11 were identified. Higher number of differentially-expressed genes were detected in AIRmax SS subline, which significant over-represented biological themes were related to inflammatory response and chemotaxis. Susceptible AIRmax SS mice also display high up-regulation of Ccl3, Ccl7, C3ar1, Il10, Stat3, Tirap, Trem 1, Trem 3, Mefv, Ptx3, Chi3l3 e Kras genes. Some of them co-localize with previously identified regions mapped on chromosomes 1 and 11.