Humans are approximately 99% similar with inter-individual differences caused in part by single-nucleotide polymorphisms (SNPs), which poses a challenge for the effective treatment of disease. Bioinformatics resources can help to store and analyse gene and protein information to address this challenge, however these resources have limitations, so the collation and biocuration of gene and protein information is required. Using the large conductance calcium- and voltage-activated potassium channel, also known as the Big Potassium (BK) channel as an example, due to its ubiquitous expression and widespread varied role in human physiology, this study aimed to prioritise SNPs with the potential to affect the function of the channel. Using a BK channel resource created with bioinformatics tools and published literature, mSlo SNPs H55Q and G57A, located in the S0-S1 linker, were prioritised and selected for lab-based verification. These SNPs flank three cysteine residues proven to modulate channel cellular distribution via palmitoylation, a reversible process shown to increase protein association with the cell membrane. The SNPs alter the predicted palmitoylation status of C56, one of the cysteine residues located in the S0-S1 linker. The cellular distribution of BK channels incorporating the SNPs was assessed using confocal microscopy and revealed that the direction and magnitude of SNP mimetic cell membrane expression was closely related to the C56 predicted palmitoylation score; a 'C56 palmitoylation pattern' was observed. It was shown that exposure to metabolic substrates glucose, palmitate and oleate modulated SNP-mimetic cellular distribution and could invert the 'C56 palmitoylation pattern', indicating that there is interplay between the metabolic status of the cell and the amino-acid composition of the channel via palmitoylation. The creation of a novel BK channel resource in this thesis highlighted the limitations, and inter-dependency of bioinformatics and lab based experimentation, whilst SNP verification experiments solidified the link between S0-S1 cysteine residues and BK cellular distribution. BK channel function is linked with a number of physiological processes; thus, the potential clinical consequences of the SNPs prioritised in this thesis require further research.

Submitted by DIEGO GABRIEL TORRES DINI null (diego.torres.dini@gmail.com) on 2017-02-25T21:08:29Z No. of bitstreams: 1 Diego Torres Dini Tese Doutoral.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-07T13:42:52Z (GMT) No. of bitstreams: 1 torresdini_dg_dr_ilha.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) / Made available in DSpace on 2017-03-07T13:42:52Z (GMT). No. of bitstreams: 1 torresdini_dg_dr_ilha.pdf: 1232376 bytes, checksum: dc45dfe7c23a8fd647db24acb963c71c (MD5) Previous issue date: 2017-02-03 / Outra / In Uruguay, reforestation with Eucalyptus sp. is of fundamental importance to produce paper, pulp and wood. The productivity of these continually grows due to application of breeding techniques, such as hybridization. This study aimed to investigate genetic parameters, productivity, stability, adaptability and to identify SNP markers associated with the diameter breast height (DBH) for to select Eucalypts grandis x Eucalyptus globulus full-sibs hybrid clones. The study was conducted in a clonal test, repeated at two different soils, in the state of Rio Negro, Uruguay. The population was phenotypically characterized to the DBH at 48 months of age and cambium tissues of each individual were sampled for genotyping with EuCHIP60K chip. The mean growth in DBH was similar between both places. The genotype-environment interaction was the simple type, with high genotype correlation in clones’ performance between environments (0.708), indicating the possibility of the same clones being selected for both places. Mean heritability between clones (0.724), coefficient of individual genetic variation (10.9%) and relative variation (0.916), showed the possibility of obtaining gains by selecting clones with higher growth, which was estimated in 3.1% for both sites together. A total of 15,196 markers SNPs were used in the genomic selection for the DBH, but after cleaning of SNPs data, the number was reduced for 15,196 (23.5%). The predictive capacity was expected to be low or negative (-0.15) for this population given the population size (78 individuals). We used the model rrBLUP with a validation of Jackknife. The model do not showed precision to predict the DBH. These results were consistent with theoretical expectations, which indicate that it is necessary to have an improvement population of at least 1,000 phenotyped and genotyped individuals. The DBH is the most important trait in the breeding of the genus Eucalyptus. However its quantitative nature added to the time necessary for this phenotype to develop makes the early detection of this trait are difficult. The identification of molecular markers associated with quantitative phenotypes is a good choice for the identification of QTLs that will help the early detection of individuals with high DBH. Significant markers associated to DBH , were indentificated into the chromosome 6, suggesting the presence of a QTL in this chromosome. Since they are clones originated from vegetative propagation and a full-sibs single-progeny, they should preferably be used for reforestation based on their cloning, since mating between clones can generate endogamy by biparental inbreeding. The utilization of SNPs helped to confirm the degree of parentage between the clones as well as clonal identity control.

A performance musical requer um alto nível de habilidade em diversos parâmetros como coordenação motora, atenção e memória, o que a torna uma atividade particularmente susceptível aos estados de ansiedade. Pesquisas nessa área têm avançado com a introdução de instrumentos específicos para abordar a ansiedade na performance musical (MPA), como é o caso da the Kenny Music Performance Anxiety Inventory (K-MPAI). Estudos recentes apontam polimorfismos genéticos envolvidos na base do quadro de ansiedade os quais já foram descritos no genoma humano e avaliados em pacientes com autismo, ataque de pânico e na depressão. No entanto, não existia na literatura mundial qualquer estudo relacionando polimorfismos de DNA e MPA. O presente estudo teve duas fases. A primeira fase, com objetivo traduzir, adaptar e validar a K-MPAI para a língua portuguesa e a segunda fase, o objetivo foi avaliar polimorfismos genéticos possivelmente associados à MPA. Após a autorização da autora, a escala KMPAI foi traduzida e validada. A escala em língua portuguesa foi aplicada a 218 músicos de ambos os sexos, amadores e profissionais. Para a validação concorrente, foi utilizado o Inventário de Ansiedade Traço-Estado (IDATE), versão validada na língua portuguesa da State Trait Anxiety Inventory (STAI). A análise da consistência interna apresentou alfa de Cronbach=0.957 com p<0.001, reprodutibilidade com p=0.378 e validação concorrente com a IDATE com alfa de Cronbach=0.642 e p<0.001. O estudo de validação permitiu considerar a amostra com graus de confiabilidade e reprodutibilidade elevados, o que traduz este estudo como provindo de uma amostra não tendenciada e replicável a outras populações. A validação concorrente entre a K-MPAI e a IDATE permite inferir que ambas são comparáveis na capacidade de medir os níveis de MPA. Na segunda fase, foi analisada a associação entre polimorfismos dos genes GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) e TMEM132D (rs900256) e o quadro de MPA. Após a aplicação da escala K-MPAI em 307 músicos (197 homens e 110 mulheres) amostras de sangue periférico foram coletadas de dos 80 sujeitos das extremidades da curva de distribuição de scores da K-MPAI (35 homens e 45 mulheres), sendo seu DNA usado para genotipagens. Análises das freqüências genotípicas e alélicas não evidenciaram diferenças estatisticamente significativas entre os grupos polares, muito embora tendências à significância fossem observadas em alguns casos, quando os gêneros foram avaliados separadamente, sugerindo que mais indivíduos devam ser analisados. A detecção de polimorfismos de DNA associados à MPA poderá permitir uma melhor compreensão dos mecanismos moleculares associados a este quadro que também ocorre em outras situações de exposição em diversas áreas de atuação. Além disso, futuros estudos poderão permitir delinear exames prognósticos e diagnósticos mais precisos, levando a um melhor conhecimento da origem da MPA / Music performance requires high levels of ability in parameters such as coordination, attention and memory, which makes it particularly susceptible to anxiety states. Scales were recently developed to evaluate and quantify music performance anxiety (MPA). However, although we are able to measure MPA, biomarkers for this condition are not available and its biological basis has not been established. On the first part of this work, we translated, adapted and validated the K-MPAI to Portuguese, generating the first MPA evaluation instrument in the language. After authorization from the author, the K-MPAI scale was translated and validated. The scale in the Portuguese language was applied to 218 musicians of both genders, professionals and amateurs. For the concurrent validation, the IDATE inventory, a validated version of the STAI Inventory (State Trait Anxiety Inventory) was used. Consistency analyses showed Cronbach\'s alpha=0.957 with p<0.001, reproducibility with p=0.378 and concurrent validation with IDATE with Cronbach\'s alpha=0.642 and p<0.001. The validation study allowed the samples to be considered with high degrees of certainty and reproducibility, which shows that this study is based on an unbiased sample and can be replicable to other populations. On the second part of this work, we strived to contribute to the knowledge of the biological basis of MPA, validating and analyzing the frequency of DNA polymorphisms possibly associated to this condition. We searched for genes that could be involved with the anxiety processes and evaluated the polymorphisms with higher frequency and/or more capacity of causing functional alterations. The genes and the polymorphisms selected (presented with their identification codes in the dbSNP database) were: GLO1 (rs4746), GSR (rs1002149), NPY (rs16147) and TMEM132D (rs900256). The status of these polymorphisms was determined in a process of selective genotyping, from a group of 80 subjects who had the higher and lower scores in the distribution curve of the K-MPAI scores (derivating from a total of 307 musicians, having scores deviating at least 1 standard deviation in average). Tests for these polymorphisms were designed, validated and evaluated with the DNA of these 80 subjects. Analysis of the allelic and genotypic frequencies of these polymorphisms did not show associations that were statistically significant. Tendencies to significance were observed when analyses were conducted separately in each gender, suggesting that studies with higher sample size should be performed. The study of genetic polymorphisms associated to MPA has the potential for contributing to a better understanding of the biological basis of anxiety

Amaranth (Amaranthus caudatus L.) is an important pseudocereal in the Andes. The seed has excellent nutritional value (high in protein, essential amino acids, and minerals) and ample capacity for growth in diverse, harsh Andean subsistence-production conditions such as water deficiency, salt stress, and soil mineral nutrient deficiency. The objective of this study was to characterize and quantify the genetic diversity among a series of 178 mostly Peruvian amaranth genotypes using 96 biallelic single-nucleotide polymorphism (SNP) markers. A total of 96 co-dominant, biallelic markers were developed using KASPar™ assays on a 96.96 Fluidigm EP1 array system. The 178 amaranth genotypes included white-opaque and white-translucent (vitreous) putative A. caudatus seed types, along with black-seeded A. hybridus and brown-seeded types, all isolated from among 48 accessions of the CICA-UNSAAC collection. Variation among and within samples and accessions was compared for empirically determined clusters (northern, north-central, south-central, and southern Peruvian Andes). Variation was highest within samples for all groups, but only in white-seeded amaranth was the p-value significant (17.43). The greatest variation among samples was found in the vitreous-seeded group (99.35). The highest average observed heterozygosity within-groups (Ho) was 0.19 in the brown-seeded group, and expected within-group heterozygosity (He) was highest in the vitreous-seeded group (0.359). Cluster analysis (UPGMA), PCA and PCO results partitioned the amaranth accessions into six discrete clusters. Clusters did not manifest obvious structure among accessions, which indicates that genetic diversity has been conserved across a broad region of the Peruvian Andes. The diversity characterization pointed to a center of origin and domestication of A. caudatus in the Ayacucho-Cusco region of southern Peru.

Pyrenophora semeniperda is a generalist fungal pathogen that occurs primarily on monocot seed hosts. It is in the phylum Ascomycota, which includes both self-compatible (homothallic) and self-incompatible (heterothallic) species. Homothallic fungal species contain complementary mating-type (MAT) idiomorphs in a single unikaryotic strain, while heterothallic strains contain a single MAT idiomorph requiring interaction between strains of complementary mating-types for sexual reproduction to occur. Because the majority of P. semeniperda strains contained either MAT1 or MAT2, this species was provisionally categorized as heterothallic. However, many strains contain both MAT idiomorphs and appear to be homothallic. These results warranted a closer look at the MAT idiomorphs and the structure of the P. semeniperda genome in order to assure accurate characterization of the MAT locus. Additionally, an assessment of the geographic distribution of MAT idiomorphs provides us with insight into the genetic diversity of P. semeniperda and the reproductive strategies that it employs. In this study, we characterized the P. semeniperda MAT locus and assessed the idiomorph distribution of 514 isolates from 25 P. semeniperda populations collected from infected Bromus tectorum (cheatgrass) seeds. Additionally, we used simple sequence repeat (SSR) and MAT idiomorph length polymorphisms to demonstrate the existence of dikaryotic strains and pseudohomothallism in this fungus. We identified a unique variable number tandem repeat (VNTR) within each idiomorph of the MAT locus of P. semeniperda. Presence of the VNTR in all MAT loci analyzed from strains collected in the Intermountain West suggests ancient proliferation of this repeat. The persistence and effectiveness of P. semeniperda strains in the cheatgrass pathosystem depend not only on the density of the fungus in the soil, but also on the genetic heterogeneity of each population. Our study suggests that P. semeniperda genetic diversity is increased both through MAT locus-dependent sexual reproduction and asexually through anastomosis.

Marine mammals comprise a paraphyletic group of species whose current abundance and distribution has been greatly shaped by past environmental changes and anthropogenic impacts. This thesis describes molecular ecological approaches to answer questions regarding habitat requirements, genetic differentiation, and life-history trade-offs in three species of marine mammals.  The annual sea-ice dynamics of the Arctic may have large effects on the abundance and distribution of Arctic species such as the pagophilic ringed seal (Pusa hispida). Paper I describes and applies a simple molecular method for isolating and characterizing a relatively large set of single nucleotide polymorphisms (SNPs) in the ringed seal. These SNPs have been genotyped in a yet-to-be-analysed dataset which will form the basis in an assessment of the micro-evolutionary effects of annual sea-ice dynamics on ringed seal.  Current management efforts directed towards the North Atlantic fin whale (Balaenoptera physalus) are hampered by an unclear understanding of population structure. Paper II investigates the DNA basis for the high levels of genetic differentiation that have been reported in allozyme studies of the North Atlantic fin whale. We find that additional processes (at the organismal level) may have contributed to shaping the phenotype of the underlying allozyme variation. Telomeres may potentially serve as markers for determining the chronological and biological age of animals where other means of inference is difficult. Paper III describes the application and evaluation of four qPCR assays for telomere length estimation in humpback whales (Megaptera novaeangliae), finding that reliable telomere length estimates require extensive quality control. Paper IV applies the best performing qPCR assay to test whether telomeres may provide a method for genetic determination of chronological age in whales and concludes that the biological and experimental variation in telomere length estimates is too large to determine age with sufficient resolution. Finally, because telomere length and rate of telomere loss also may be affected by other cellular and organismal processes, such as resource allocation among self-maintenance mechanisms, growth and reproduction, Paper V describes the correlations between individual telomere length and rate of telomere loss, and sex, maturity status and female reproductive output. We found that the costs of reproduction in terms of telomere loss are higher in mature humpback whales than in juveniles; that reproductive costs are higher in males than females; and that differences among females tend to correlate with reproductive output. / At the time of doctoral defence the following papers were unpublished and had a status as follows: Paper 2: Submitted; Paper 3:Submitted; Paper 4: Manuscript; Paper 5:Manuscript

North Atlantic and South Atlantic swordfish (Xiphias gladius L.) are currently managed as two stocks separated at 5°N. While previous studies of genetic population structure using both mitochondrial and nuclear DNA confirm two genetically distinct stocks, sampling coverage has not been uniform or representative of all areas and estimates of admixture in areas of contact have not been provided. In this study, we examined: 1) the applicability of high-resolution melting analysis (HRMA) in population genetic studies of non-model organisms, 2) the use of nuclear markers in Atlantic swordfish and the methodology whereby nuclear gene variation can be quickly screened, identified, and genotyped using short-amplicon (SA) HRMA and unlabeled probe (UP) HRMA, and 3) the use of HRMA to characterize nuclear markers to study the genetic population structure of Atlantic swordfish using representative samples of the entire basin to provide an estimation of population admixture by means of Bayesian individual assignment. High resolution melting analysis (HRMA) is shown to be a highly sensitive, rapid, closed-tube genotyping method amenable to high throughput and, though until recently primarily confined to clinical studies, suitable for population studies in non-model species. Ten nuclear markers were genotyped primarily by SA- and UP-HRMA in North Atlantic (n=419), South Atlantic (n=296), and Mediterranean (n=59) swordfish. Comparisons of pairwise FST, AMOVA, PCoA, and Bayesian individual assignments were congruent with previous finding of three discrete populations with comparatively low levels of estimated gene flow for a marine organism (FST = 0.039-0.126). Population admixture was identified and estimated in the Northeast Atlantic and appeared to be asymmetrical, with swordfish from the South Atlantic found among North Atlantic localities but no North Atlantic migrants identified in the South Atlantic. The Mediterranean boundary currently at the Strait of Gibraltar is found to extend west into Atlantic waters to approximately 8°W. Similarly, the boundary between North and South Atlantic swordfish should be revised to a line that extends north from 0°N 45°W to 25°N 45°W and from that position, as a nearly horizontal line, eastwards to the African coast. Finally, I show that Bayesian individual assignment using the developed marker set can be used for mixed stock allocation in the Northeast Atlantic.

In malaria endemic regions, resistance to malaria constitutes a critical selective pressureon genetic polymorphisms that regulate immune defense and inflammatory pathways.Differences in malaria susceptibility between sympatric ethnic groups have been described inMali. The Fulani are less susceptible to malaria compared to the neighboring group the Dogon,in spite of similar socio-economic and environmental conditions. Paper I is focused on IL-4-590 T/C polymorphism and correlation with levels of malariaspecific IgG, IgG (1-4) subclasses as well as malaria specific and total IgE level in the two ethnicgroups. Our data show that the Fulani individual carrying the IL-4-590 T allele found to havehigher parasite carriage rate and had higher levels of malaria-specific IgG4 and IgE compared tothe individual carrying the C allele. No such differences were seen within the Dogon.Paper II investigated 166 SNPs in the human host in individuals belonging to the Fulani and theDogon ethnic groups. These SNPs were correlated with total IgG against AMA-1, MSP-1, MSP-2 and CSP antigens as well as total IgE level. All antibody levels were higher in the Fulanicompared to the Dogon and strengthens previous finding that antibodies might play a role in theprotection seen in the Fulani. We identified higher frequencies of the protective blood group O.Several allelic differences between the two ethnic groups were found in CD36, IL-4, RTN3 andADCY9. Moreover several polymorphisms in SLC22A4, IRF1, IL5, LTA and TNF have beenfound to be correlated with anti-MSP antibody level; TLR6, IL3, TNF, and IL22 found to becorrelated with anti-MSP-2 antibody level in the Fulani. Such association was not seen in theDogon. In Paper III, the same individuals, as in paper II, were investigated with a focus on the FcγRIIapolymorphism and correlation with levels of anti-AMA-1, MSP-1, MSP-2, CSP specificantibodies as well as total IgE level. The genotype distribution and allele frequency weresignificantly different between the Fulani and the Dogon with the Fulani being HH, H allele- andthe Dogon RR, R allele carriers. A correlation between the HH genotype and the H allele andprotection against mild malaria was seen in the Fulani but not in the DogonTaken together our study has found significant genetic differences between the Fulani and theDogon Ethnic groups, which suggest that ethnicity should be taken into account in monitoring ofimmunological studies and vaccines trials in malaria endemic areas.

Made available in DSpace on 2015-07-22T20:49:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-31. Added 1 bitstream(s) on 2015-08-11T03:26:15Z : No. of bitstreams: 1 Publico-12959.pdf: 1645113 bytes, checksum: 2836abcccc356e427c13763a5a6f708c (MD5) / Objetivo: Analise do fator de crescimento vasculo-endotelial (VEGF) como marcador sorologico no diagnostico da gravidez ectopica. Outrossim, e desiderato deste projeto avaliar se as variantes polimorficas -460 T/C (rs833061), -634 C/G (rs2010963) e +936 C/T (rs3025039) do gene do VEGF podem estar associadas a ocorrencia da gravidez ectopica (GE). Alem disso, procuramos avaliar se os niveis sericos de VEGF estavam correlacionados com o genotipo. Metodo: estudo caso-controle, onde foram selecionadas 35 pacientes com diagnostico de gravidez ectopica, 15 abortamentos e 22 gestacoes intra-uterinas normais. Foram coletados 10 mL de sangue em tubo seco, centrifugados a 2000 rpm e o sobrenadante foi separado em cinco aliquotas de 200 £gL e armazenados a -80 o C, para posterior avaliacao. A dosagem serica do VEGF foi realizada por metodo de ELISA - (human VEGF; R&D systems, Minneapolis). Para a avaliacao dos polimorfismos do gene do VEGF foram incluidas 74 pacientes com historia previa ou em vigencia de GE, em acompanhamento no Ambulatorio de GE da UNIFESP. O grupo controle foi constituido de 134 mulheres na menopausa, com pelo menos duas gestacoes normais, sem abortos ou GE durante a menacme, em seguimento no Ambulatorio de Climaterio da UNIFESP. Foram coletados 10 mL de sangue periferico, retirado buffy-coat, do qual e extraido DNA genomico pela tecnica de DTAB / CTAB. A genotipagem foi realizada digerindo os produtos de PCR com as enzimas de restricao especificas para os polimorfismos do gene de VEGF +936 C/T, -634 C/G e -460 C/T. Os dados foram analisados pelo teste ƒÓ2 ou teste exato de Fisher, sendo considerado significante p<0,05. Resultados: Nos casos estudados a media dos valores sericos do VEGF foi de 297,5 pg/mL na gravidez ectopica, 299,6 pg/mL no abortamento e de 39,9 pg/mL nas gestacoes intra-uterinas normais (p<0,0001). Nao foram identificadas diferencas significantes quanto as frequencias genotipicas e alelicas para os polimorfismos do gene do VEGF +936 C/T (p=0,28), -460 C/T (p=0,70) e -634 G/C (p=0,17). Nao foi identificada relacao entre os valores sericos de VEGF e os genotipos para nenhum dos polimorfismos de VEGF testados. Conclusao: Nossos resultados sugerem que na gravidez ectopica sejam detectados valores sericos mais elevados de VEGF do que na gravidez intra-uterina viável. Por outro lado, quando comparamos os valores de VEGF na gravidez ectópica com os casos de abortamento, não encontramos diferença estatisticamente significante. Não foi identificada associação entre a expressão de polimorfismo +936 C/T, -634 C/G e -460 C/T do gene do VEGF e nem de seus alelos com a ocorrência de gravidez ectópica. Não foi identificada relação entre os níveis séricos de VEGF e os genótipos para nenhum dos polimorfismos de VEGF testados. A produção de VEGF sérico parece não ter correlação com o genótipo. / TEDE / BV UNIFESP: Teses e dissertações

Made available in DSpace on 2016-06-02T20:21:35Z (GMT). No. of bitstreams: 1 6190.pdf: 937316 bytes, checksum: ab23c07a84b6ef5293322fb74683c2b5 (MD5) Previous issue date: 2014-01-24 / Financiadora de Estudos e Projetos / The Beef cattle production is a very important economic activity for Brazil, which is a global producer and exporter of bovine-derived products and currently contains the world s largest beef cattle herd. However, the majority Brazilian cattle are adapted to a tropical climate and have low meat and carcass quality. The crossbreeding between Charolais and Zebu animals resulted in development of Canchim breed. This breed shows better resistance to high temperatures and parasites, as well as better meat and carcass quality. New genotyping and computational technologies can enable the use of single nucleotide polymorphism (SNP) in breeding programs. The high demand for meat quality and the aggressive competition among other beef exporting countries justifies studies focused on improving carcass traits, such as ribeye area (REA), which can provide more efficiency production of meat cuts for consumption. The objective in this study was to validate SNPs selected in a previous genomewide association study (GWAS) for REA performed by Random Forest methodology in 400 animals genotyped with the BovineHD BeadChip ( Illumina®) which yielded a set of 197 SNPs. First, we analyzed the linkage disequilibrium (LD), and then we annotated the associated regions. After verifying this set of SNPs, we selected four SNPs located on BTA4, BTA10, BTA22 and BTA27 for validation purposes. These SNPs were genotyped by RFLPPCR in approximately 712 bovine. We analyzed the genetic effect of these SNPs the using GLM procedure in SAS (P &#8804; 0,05), which identified SNPs in BTA4 and BTA27 as contributing some genetic effect on REA. Furthermore, we found significant additive effect (P&#8804; 0,05) for the SNP on BTA 27, and a significant dominance effect for the SNP in BTA 4 using the ASReml software. The GWAS for REA identified one region between 34989224pb and 36989224pb using haplotype association analysis with the PLINK software that indicated two regions (P&#8804; 0,05) in the SFRP1 and ANK1 genes associated with REA. / A bovinocultura de corte brasileira se destaca na economia nacional, sendo o Brasil atualmente um dos principais produtores e exportadores de produtos cárneos de origem bovina, apresentando o maior rebanho comercial do mundo. No entanto, a maioria dos rebanhos bovinos são caracterizados por animais com maior adaptabilidade a ambientes tropicais e baixa qualidade de carcaça e carne. Cruzamentos entre raças taurinas e zebuínas originaram a raça Canchim, sendo esta vantajosa em relação à produtividade, conformação da carcaça e resistência ao calor e a parasitas. Com as novas tecnologias de genotipagem e computacionais se renovou o interesse em viabilizar o uso da informação de marcadores genéticos do tipo SNP em programas de seleção e melhoramento. O mercado interno mais exigente e maior competição entre países exportadores justificam estudos em características de carcaça, como área de olho de lombo (AOL), que pode proporcionar maior rendimento em cortes de alto valor agregado. Diante deste contexto, o objetivo desse trabalho foi validar SNPs selecionados por estudo prévio de associação genômica ampla (GWAS) para área de olho de lombo, realizada por Random Forest em uma população composta por 400 animais Canchim e genotipados em BovineHD BeadChip (Illumina®) e que resultou em um conjunto de 197 SNPs. Inicialmente estudou-se o desequilíbrio de ligação no genoma bovino da raça Canchim e realizou-se anotação das regiões associadas. A mineração desse conjunto resultou em 4 SNPs, os quais foram selecionados para as análises de validação e localizam-se nos cromossomos BTA4, BTA10, BTA22 e BTA27. Os marcadores selecionados foram genotipados pela técnica RFLP-PCR em uma população de 712 bovinos da raça Canchim. Analisou-se o efeito desses marcadores sobre o valor genético aditivo (VGA) de AOL por meio de análise de variância que indicou a influência dos SNPs localizados nos BTA4 e BTA27. Além disso, tais SNPs significativos nas análises de validação foram analisados quantos aos efeitos aditivos e de dominância pelo teste Wald F, tendo sido observado efeito 6 de dominância significativo no SNP do BTA4 e efeito aditivo significativo no SNP do BTA 27. A análise de associação haplotípica com área de olho de lombo realizada na região 34989224pb a 36989224pb no BTA27 por meio de análise de regressão logística indicaram duas regiões nos genes SFRP1 e ANK1 associadas com a característica.