Made available in DSpace on 2015-08-20T17:09:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-25. Added 1 bitstream(s) on 2015-08-20T17:26:22Z : No. of bitstreams: 1 000839743.pdf: 1325053 bytes, checksum: 7f7ef6fc911604d218b6c604c45c4d61 (MD5) / A Citogenética humana é o estudo dos cromossomos, sua estrutura e sua herança, aplicado à prática da genética médica. Há quase 50 anos as anomalias cromossômicas, alterações microscopicamente visíveis no número e/ou na estrutura dos cromossomos, podem ser responsáveis por uma série de condições clínicas denominadas aberrações cromossômicas, que constituem uma categoria de doenças genéticas constitucionais ou adquiridas. Diversas alterações foram descritas em doenças genéticas e doenças neoplásicas de origem hematológica, auxiliando no diagnóstico, prognostico, classificação e monitoramento da doença. O objetivo do presente estudo foi padronizar a técnica clássica em citogenética através da avaliação do bandeamento G pela digestão enzimática com tripsina e pela desnaturação com tampão citratado em alta temperatura, auxiliando na visualização do cariótipo. Neste estudo utilizamos amostras de sangue periférico de indivíduos normais. A cultura celular foi realizada pelo método de cultura in situ, seguindo a metodologia de Moorhead et al. modificada (1960). Em todos os casos foram obtidas metáfases adequadas para análise e o índice mitótico foi satisfatório. Os resultados obtidos pelo emprego de diferentes técnicas de bandeamento cromossômico revelaram que o bandeamento G pela ação enzimática da tripsina embora considerado padrão-ouro é mais sensível, trabalhoso e ocorre com um número maior de tentativas devido a variabilidade do tempo para que ocorra a degradação das proteínas, sendo necessário o retrabalho tornando-se ineficiente em amostras com baixo índice mitótico e aumentando consequentemente o custo do exame. Enquanto o bandeamento pela técnica utilizando tampão citratado em alta temperatura é simples, produtivo, ágil e de menor custo / Human Cytogenetics is the study of chromosomes, their structure and their inheritance, applied to the practice of medical genetics. For nearly fifty years the chromosomal abnormalities, microscopically visible changes in the number and / or structure of chromosomes, may be responsible for a number of clinical conditions known as chromosomal aberrations, which are a category of constitutional or acquired genetic diseases. Several amendments were described in genetic diseases and neoplastic diseases of hematologic origin, aiding in the diagnosis, prognosis, classification and monitoring of the disease. The aim of this study was to standardize the classical technique in cytogenetics by evaluating the banding G by enzymatic digestion with trypsin and by denaturation with citrate buffer at high temperature, assisting in the karyotype view. In this study we used peripheral blood samples of normal individuals. Cell culture was performed by culturing in situ method, following the method of Moorhead et al. modified (1960). In all cases appropriate metaphases were obtained for analysis and the mitotic index was satisfactory. The results obtained by using different chromosome banding techniques revealed that the G banding by the enzymatic action of the trypsin although considered the gold standard it is more sensitive, cumbersome and it occurs with a larger number of retries due to a variability of the time for degradation of the proteins, requiring rework, this way becoming inefficient in samples with low mitotic index and consequently increasing the cost of the exam. While the banding technique using citrate buffer in high temperature is simple, productive, agile and less expensive

Uma população experimental F2 foi desenvolvida a partir do cruzamento de uma linhagem macho de frangos de corte com uma linhagem de postura, com o objetivo de mapear QTLs (locos controladores de características quantitativas) para características de desempenho e carcaça. Um total de 2.063 animais F2 em 21 famílias de irmãos completos obtidas em 17 incubações. As aves foram criadas como frangos de corte e abatidas a 6 semanas de idade, foram avaliadas 19 características de desempenho e carcaça. A genotipagem foi realizada em 3 fases: 1) Um total de 80 marcadores microssatélites do cromossomo 1 foram testados nos indivíduos parentais e F1 para identificar marcadores informativos. 2) Genotipagem seletiva dos indivíduos F2 que representam os extremos fenotípicos para peso vivo aos 42 dias de idade (P42), para identificar regiões potencialmente associadas (P < 0,10) com esta característica. 3) Sete famílias de irmãos completos (649 F2) foram genotipados para 12 marcadores associados na fase 2 e para 14 marcadores flanqueadores. Mapeamento por intervalo utilizando regressão foi aplicado para dois modelos genéticos (F2 e meio-irmãos) para detectar QTLs Foram encontradas fortes evidências de QTLs afetando peso vivo, consumo de ração, conversão alimentar e peso de asas, coxas e sobrecoxas, peito, gordura abdominal, fígado, pulmão e coração no cromossomo 1. / An F2 chicken population was developed by crossing a broiler sire line and a layer line, with the objective of mapping Quantitative Trait Loci (QTL) for performance and carcass traits. A total of 2,063 F2 chicks in 21 full-sib families from 17 hatches were reared as broilers and slaughtered at 6 weeks of age. Nineteen performance and carcass quality traits were measured. The genotyping was done in three phases: 1) A total of 80 microsatellite markers from chromosome 1 were tested in the parental and F1 individuals to identify informative markers. 2) Selective genotyping of F2 individuals, representing extreme phenotypes for body weight at 42 days of age (BW42), to identify regions potentially associated (P < 0,10) with this trait. 3) Seven full-sib families (649 F2 chicks) were genotyped for 12 markers associated in phase 2 and for additional 14 flanking markers. Interval mapping using regression methods was applied to two different genetic models: 1) Line-cross; 2) Half-sib analyses for mapping QTL. Strong evidences for QTL affecting body weight, feed intake, feed conversion and weights of drums and thighs, breast, abdominal fat, liver, lung and heart were found on chromosome 1.

Made available in DSpace on 2014-06-11T19:27:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-22Bitstream added on 2014-06-13T19:35:15Z : No. of bitstreams: 1 boschiero_c_me_botfmvz.pdf: 659097 bytes, checksum: 7983c4a2922fd57ea2f00e34dedf4a2e (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O objetivo deste trabalho foi identificar locos controladores de características quantitativas (QTLs) nos cromossomos 11 e 13 de galinhas (Gallus gallus) para características de desempenho e carcaça. A partir do cruzamento entre uma linhagem de corte e uma de postura, foi gerada a população experimental F2 na Embrapa Suínos e Aves. Foram avaliadas as seguintes informações fenotípicas: peso ao nascer, peso aos 35, 41 e 42 dias, ganho de peso, consumo de ração, eficiência e conversão alimentar dos 35 aos 41 dias e valores de hematócrito. As carcaças foram evisceradas e avaliados: o comprimento do intestino, peso dos pulmões, do fígado, do coração e da moela. Foram obtidos após quatro horas de resfriamento: peso da carcaça, gordura abdominal, peso de partes: peito, coxas, dorso, asas, cabeça e pés. Quatro e cinco marcadores microssatélites dos cromossomos 11 e 13, respectivamente, foram genotipados num total aproximado de 330 animais F2 em quatro famílias de irmãos-completos. Os mapas de ligação para ambos os cromossomos foram construídos e a análise de mapeamento de QTLs baseada no modelo genético de F2 foi realizada. No cromossomo 11 foram mapeados dois QTLs sugestivos: para peso de pés e de moela, ambos posicionados no intervalo entre ADL0123 e ADL0210. No cromossomo 13 foi mapeado um QTL sugestivo para peso de coração posicionado no intervalo entre MCW0110 e MCW0104. / The objective of this study was to identify quantitative trait loci (QTLs) for performance and carcass traits in chicken (Gallus gallus) chromosomes 11 and 13. From the crossbreeding of a broiler and a layer line, an F2 experimental population was generated at the Embrapa Suínos e Aves. The following phenotypic data were recorded: body weights at birth, 35, 41 and 42 d; weight gain, feed consumption and feed conversion from 35 to 41 d; weights of carcass, carcass parts, organs and abdominal fat, hematocrit and length of intestine. Four and five microsatellite markers from chromosomes 11 and 13, respectively, were genotyped in approximately 330 F2 chickens from four full-sib families. The linkage maps for both chromosomes were constructed and the QTL mapping analyses were carried out based on an F2 genetic model. Two suggestive QTLs were mapped to chromosome 11: for feet and gizzard weights, both located in the interval between ADL0123 and ADL0210. On chromosome 13 one suggestive QTL for heart weight was detected in the interval between MCW0110 and MCW0104.

Orientador: José Maurício Barbanti Duarte / Banca: Fausto Foresti / Banca: Cláudio de Oliveira / Banca: Orlando Moreira Filho / Banca: Vera Fernanda Martins Hossepian de Lima / Resumo: Estudos com veado-mateiro (Mazama americana) mostram que há muitas controvérsias quanto ao número de subespécies ou até quanto ao desdobramento destas em espécies. Em estudo citotaxonômico foram encontradas variações cromossômicas intra e interpopulacionais em populações de M. americana geograficamente distantes, com número diplóide de 48 a 53 e número fundamental de 46 a 57. Com base nisto, o presente estudo visou compreender como ocorreu a reorganização cromossômica dentro das variantes encontradas durante a evolução do grupo. Para isto, estrutura e organização dos cromossomos de M. americana foram analisadas para identificar os rearranjos que originaram a variação intraespecífica através das técnicas de bandamento cromossômico (bandas G, C, Ag-NOR), hibridação in situ (FISH) com sondas teloméricas e pintura cromossômica com o uso de sondas cromossômicas da espécie Mazama gouazoubira. Foram identificados seis citótipos distribrídos em 12 cariótipos diferentes: Rondônia (2n=42 ou 43 e NF=46; 2n=42 e NF=49), Juína (2n= 43, 44 ou 45 e NF=48; 2n=44 e NF=46), Jarí (2n=49; NF=56, Carajás (2n=50 e NF=54), Santarém (2n=51 e NF=56) e Paraná (2n=51,52 ou 53 e NF=56). O cariótipo básico do citótipo Paraná foi utilizado como base comparativa para os demais. Os rearranjos que originaram essas diferenças foram fusões cêntricas, em tandem e inversões pericêntricas. A análise de complexo sinaptonêmico confirmou a existência de um sistema sexual múltiplo do tipo XX/XY1Y2 através da detecção de uma trivalente sexual. Sítios teloméricos intersticiais evidenciam que a ocorrência de eventos de fusões em tandem foi essencial para a evolução cariotípica desta espécie e a homologia de sondas cromossomo-específicas de M. gouazoubira corroboram que o caminho da reorganização cromossômica entre estas espécies foi principalmente através de fusões. / Abstract: Studies with the red brocket deer (Mazama americana) shown that there are a lot of controversies about the number of subspecies or about the unfolding of these in new species. Citotaxonomic studies found intra and interpopulational chromosomal variations, with diploid number varing from 48 to 53 and fundamental number from 46 to 57. Based on these studies, the aim of the present study was understood how the chromosomal reorganization occurred between this variants during the evolution process. For that, we analyzed the chromosomal structure and organization of M. americana, identifying the rearrangements responsible for the intraspecific variation through chromosome banding (G and C-banding, Ag-NOR), in situ hybridization of telomeric probes and chromosome painting using probes of M. gouazoubira species. It were found six different variants: Rondônia (2n=42 or 43 and FN=46; 2n=42 and FN=49), Juína (2n= 43, 44 or 45 and FN=48; 2n=44 and FN=46), Jarí (2n=49 and FN=56), Carajás (2n=50 and FN=54), Santarém (2n=51 and FN=56) and Paraná (2n=51,52 or 53 and FN=56). The basic karyotype of Paraná variant was choosing for comparative analysis. The rearrangements responsible for these chromosomal differences were centric and tandem fusions and pericentric inversions. The synaptonemal analysis sustained the existence of a multiple sexual system (XX/XY1Y2) with detection of a sexual trivalent. Intersticial telomeric sites shown the occurrence of tandem fusions was essential for the karyotype evolution of this species and the homology with the probes of M. gouazoubira corroborated that the way of chromosomal reorganization between these species was mainly through chromosome fusions. / Doutor

A análise do conteúdo gênico do cromossomo Y em 12 espécies de Drosophila com genoma sequenciado em 2008 mostrou que o Y é pouco conservado entre espécies e está em processo de aquisição de genes, o que contradiz o modelo atual de evolução de cromossomos sexuais que o descreve como um homólogo degenerado do X, com constante perda de genes. Este resultado inicial incitou o estudo espécies adicionais de Drosophila e de gêneros próximos. Uma dificuldade relevante para obtenção de espécimes é que muitos grupos taxonômicos de drosofilídeos não estão disponíveis nos &ldquo;stock-centers&rdquo;, e seus hábitos de vida são pouco conhecidos. Muitas espécies são encontradas na natureza associadas a fungos, flores, ou exsudados vegetais, e raramente são atraídas por isca com banana fermentada, que é o método usual de coleta de drosofilídeos. Os objetivos do presente trabalho foram: I) analisar o conteúdo gênico do cromossomo Y de drosofilídeos provenientes de substratos &ldquo;não usuais&rdquo;, II) determinar substratos de desenvolvimento larval e identificar espécies novas, e III) analisar a composição de bases de genes no Y. Os resultados revelam a natureza dinâmica de aquisição e perdas de genes do cromossomo Y na família Drosophilidae que, em poucos casos, inclui um movimento de todo o cromossomo (p.e., fusão do Y a um autossomo). Descrevemos uma nova espécie, Drosophila calatheae, cuja larva se desenvolve em flores do gênero Calathea (Marantaceae). Uma segunda espécie, provisoriamente codificada como Drosophila I4, e cujas larvas também se desenvolvem nessas flores, está em fase de descrição. A partir de análise morfológica, nenhuma dessas duas espécies pôde ser incluídas em algum dos grupos de espécies conhecidos. Uma filogenia molecular preliminar com dois genes do cromossomo Y (kl-3 and kl-5) sugere que ambas pertencem à radiação virilis-repleta e que D. calatheae tem relações (morfológicas e moleculares) com as espécies do grupo bromeliae. A análise do conteúdo GC de genes no Y mostrou que genes neste cromossomo são enriquecidos em AT em relação a genes autossômicos, e esta diferença na composição de bases é proporcional ao tempo que um gene está presente no Y. Portanto, o conteúdo GC pode servir como ferramenta no estudo da evolução do cromossomo Y ao determinar o estado ancestral de um gene (autossômico vs. ligado ao Y) e datar o movimento de genes entre esses dois compartimentos genômicos / The analyses of the Y chromosome gene content in 12 Drosophila species whose genome were sequenced in 2008 showed that the Y is not well conserved among species and is currently in the process of acquiring genes, contradicting the current model of sex chromosome evolution that describes the Y as a degenerate homolog of the X, in constant gene loss. This initial result prompted the study of additional Drosophila species and related genera. One of the difficulties in obtaining specimens is the fact that drosophilids from many taxonomic groups are not available in stock- centers and little is known about their ecology. Many species are found in nature associated with fungi, flowers, or plant exudates, and are rarely attracted to baits with fermented banana, the usual method of collecting drosophilids. The objectives of this study were: I) analysis of the Y chromosome gene content of species from \"unusual\" substrates, II) determination of drosophilids breeding / larval development sites, and III) analysis of the base composition of genes in the Y chromosome. The results emphasize the Y-chromosome dynamic nature of genes acquisition and loss in the family Drosophilidae, including a few cases of whole chromosome movements (p.e., Y-autosome fusion). We describe a new species, Drosophila calatheae, whose larvae develop in flowers of the genus Calathea (Marantaceae). Drosophila I4 (to be described) also breeds in these flowers. None of these two species could be included in a known taxonomic group of species. A phylogeny with two Y-chromosome genes (kl-3 and kl-5) suggests that they belong to the virilis-repleta radiation and D. calatheae is related to the bromeliae group. Analysis of base composition of Y-chromosome genes shows that they are AT-rich when compared to autosomal genes, and this difference is proportional to the time that a gene has been in the Y. Thus, GC content can be a tool to study the evolution of this chromosome

In this thesis, we study the physics of the pulled polymer loops motivated by a biological problem of chromosome alignment during meiosis in fission yeast. During prophase I of meiotic fission yeast, the chromosomes form a loop structure by binding their telomeres to the Spindle Pole Body (SPB). SPB nucleates the growth of microtubules in the cytoplasm. Molecular motors attached to the cell membrane can exert the force on the microtubules and thus pull the whole nucleus. The nucleus performs oscillatory motion from one to the other end of the elongated zygote cell. Experimental evidence suggests that these oscillations facilitate homologous chromosome alignment which is required for the gene recombination. Our goal is to understand the physical mechanism of this alignment. We thus propose a model of pulled polymer loops to represent the chromosomal motion during oscillations. Using a freely-jointed bead-rod model for the pulled polymer loop, we solve the equilibrium statistics of the polymer configurations both in 1D and 3D. In 1D, we find a peculiar mapping of the bead-rod system to a system of particles on a lattice. Utilizing the wealth of tools of the particle system, we solve exactly the 1D stationary measure and map it back to the polymer system. To address the looping geometry, the Brownian Bridge technique is employed. The mean and variance of beads position along the loop are discussed in detail both in 1D and 3D. We then can calculate the three-dimensional statistics of the distance between corresponding beads from a pair of loops in order to discuss the pairing problem of homologous chromosomes. The steady-state shape of a three-dimensional pulled polymer loop is quantified using the descriptors based on the gyration tensor. Beyond the steady state statistics, the relaxation dynamics of the pinned polymer loop in a constant external force field is discussed. In 1D we show the mapping of polymer dynamics to the well-known Asymmetric Simple Exclusion Process (ASEP) model. Our pinned polymer loop is mapped to a half-filled ASEP with reflecting boundaries. We solve the ASEP model exactly by using the generalized Bethe ansatz method. Thus with the help of the ASEP theory, the relaxation time of the polymer problem can be calculated analytically. To test our theoretical predictions, extensive simulations are performed. We find that our theory of relaxation time fit very well to the relaxation time of a 3D polymer in the direction of the external force field. Finally, we discuss the relevance of our findings to the problem of chromosome alignment in fission yeast.

Abstract The influence of the X and Y chromosomes on the size and shape of the dental arches and occlusion as well as on craniofacial cephalometric dimensions, angles and dimensional ratios is studied. The material consists of Finnish patients with sex chromosome aneuploidies and normal population controls from the "Kvantti Study" series, which was collected in the 1970's and 1980's at the Institute of Dentistry, University of Turku. The patients are five individuals with complete testicular feminization (CTF), eight 47,XYY males, and fourteen 45,X/46,XX females. The controls are population female and male controls, as well as five first degree relatives of the individuals with CTF, three of the 47,XYY males and nine of the 45,X/46,XX females studied. Dental arch dimensions and occlusion as well as craniofacial cephalometric dimensions, angles and dimensional ratios are measured from dental study casts and standardized lateral cephalograms. The results show that the presence of the Y chromosome in 46,XY females and the supernumerary Y chromosomal gene(s) in 47,XYY males result in the enlargement of the dental arches and craniofacial dimensions without substantial effects on dimensional ratios and plane angles, but with special influence on the growth of the mandibular corpus. The reduction of X chromosomal genetic material in 45,X/46,XX females results in the reduction of craniofacial dimensions, affecting dimensional ratios and especially plane angles of the cranial base.

Mammalian nuclear function depends on the complex interaction of genetic and epi-genetic elements coordinated in space and time. Structure and function overlap to such a degree that they are usually considered as being inextricably linked. In this work I combine an experimental approach with a computational one in order to answer two main questions in the field of mammalian chromosome organization. In the first section of this thesis, I attempted to answer the question, to what extent does chromatin from different chromosome territories share the same space inside the nucleus? This is a relatively open question in the field of chromosome territories. It is well-known and accepted that interphase chromosomes are spatially constrained inside the nucleus and that they occupy their own territory, however, the degree of spatial interaction between neighbouring chromosomes is still under debate. Using labelling methods that directly incorporate halogenated DNA precursors into newly replicated DNA without the need for immuno-detection or in situ hybridization, we show that neighbouring chromosome territories colocalise at very low levels. We also found that the native structure of DNA foci is partially responsible for constraining the interaction of chromosome territories as disruption of the innate architecture of DNA foci by treatment with TSA resulted in increased colocalisation signal between adjacent chromosomes territories. The second major question I attempted to answer concerned the correlation between nuclear function and the banding pattern observed in human mitotic chromosomes. Human mitotic chromosomes display characteristic patterns of light and dark bands when visualized under the light microscope using specific chemical dyes such as Giemsa. Despite the long standing use of the Giemsa banding pattern in human genetics for identifying chromosome abnormalities and mapping genes, little is known about the molecular mechanisms that generate the Giemsa banding pattern or its biological relevance. The recent availability of many genetic and epigenetic features mapped to the human genome permit a high-resolution investigation of the molecular correlates of Giemsa banding. Here I investigate the relationship of more than 50 genomic and epigenomic features with light (R) and dark (G) bands. My results confirm many classical results, such as the low gene density of the most darkly staining G bands and their late replication time, using genome-wide data. Surprisingly, I found that for virtually all features investigated, R bands show intermediate properties between the lightest and darkest G bands, suggesting that many R bands contain G-like sequences within them. To identify R bands that show properties of G bands, I employed an unsupervised learning approach to classify R bands on their genomic and epigenomic properties and show that the smallest R bands show a tendency to have characteristics typical of G bands. I revisit the evidence supporting the boundaries of G and R bands in the current cytogenomic map and conclude that inaccurate placement of weakly supported band boundaries can explain the intermediate pattern of R bands. Finally, I propose an approach based on aggregating data from multiple genomic and epigenomic features to improve the positioning of band boundaries in the human cytogenomic map. My results suggest that contiguous domains showing a high degree of uniformity in the ratio of heterochromatin and euchromatin sub-domains define the Giemsa banding pattern in human chromosomes.

Mutagen-sensitive (mus) mutations in Drosophila melanogaster render developing flies hypersensitive to the lethal effects of DNA-damaging agents. In general, mus mutations identify DNA repair-related genes. In this study, 5 new second chromosome mus mutations (mus205B¹, mus208B¹, mus209B¹, mus210B¹ and mus211B¹), selected on the basis of sensitivity to methyl methanesulfonate (MMS), were characterized using a variety of genetic tests. One test measured the MMS-sensitivity of double mutant mus strains compared to their component single mutants. Mutant interactions were examined in 8 double mus and in 2 triple mus strains containing combinations of mus201D¹, mus205B¹, mus208B¹, mus210B¹ and mus211B¹ (or mus211B²). These analyses have revealed predominantly synergistic and epistatic responses to MMS. Taken together with the findings of previous genetic and biochemical studies of Drosophila mus strains, these results suggest that 3 major repair pathways may operate in flies to correct damage caused by MMS. Mutagen cross-sensitivity data and the results of the interaction studies suggest that mus mutations might serve as rapid and sensitive bioassays of somatic genotoxicity caused by mutagens and carcinogens. To explore this possibility, a simple mutagen test system was devised employing triple mutant mus strains. One strain (mus208B¹ mus210B¹ mus211B²) was tested for sensitivity to 14 mutagens/carcinogens and 2 non-carcinogens. Eleven of the mutagens/carcinogens were readily detected as genotoxic. Both non-carcinogens were non-genotoxic. These preliminary results demonstrate the feasibility (and some limitations) of the proposed somatic genotoxicity assay and emphasize the need for further test validation using a larger chemical data base. The temperature-sensitive lethal mutation mus209B¹ was subjected to extensive genetic analyses and to temperature shift experiments during development. This locus was found to encode a product(s) that (1) is essential for viability at virtually all pre-imaginal developmental stages (the latter half of pupation appears to be an exception), (2) is necessary for wildtype levels of resistance to the genotoxic effects of MMS and ionizing radiation, and (3) is required for female fertility. Confirmation of the pleiotropic nature of this mutation was obtained by meiotic and cytogenetic mapping studies and by complementation tests with a series of allelic mutations. The mus209B¹ phenotypes are similar to ones conferred by mutations in Drosophila and yeast that disrupt various aspects of chromosome metabolism. In this context, some possible roles for mus209B¹ are discussed. / Science, Faculty of / Zoology, Department of / Graduate

Orientador: Anete Pereira de Souza / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T12:23:33Z (GMT). No. of bitstreams: 1 Laborda_PriandaRios_D.pdf: 3045492 bytes, checksum: d1a998a5b1c4300247471d90da1ee8da (MD5) Previous issue date: 2011 / Resumo: Drosophila mediopunctata, mosca não cosmopolita de distribuição neotropical e pertencente ao grupo tripunctata do subgênero Drosophila, é uma espécie utilizada por alguns grupos no Brasil como modelo em estudos com enfoque evolutivo. Abordagens que exploram a biologia da espécie, tais como a detecção de variação genética natural e a influência de inversões cromossômicas na dinâmica populacional são costumeiramente usadas. Todavia, essa espécie não possui disponíveis marcadores moleculares que facilitem a investigação das bases genéticas que norteiam os eventos explorados até agora. Os microssatélites são marcadores moleculares consagrados e a ferramenta de escolha no estudo de diversos organismos pela simplicidade de uso e de análise. Entretanto, para espécies que ainda não têm grande parte de seu genoma seqüenciado, a obtenção de marcadores desse tipo passa pela necessidade de desenvolvimento via bibliotecas genômicas. Esse trabalho objetivou desenvolver, caracterizar e mapear microssatélites em D. mediopunctata para que estudos de variação morfológica, de identificação de regiões genômicas associadas a fenótipos de interesse, de genética de populações entre outros possam ser realizados com o respaldo de dados moleculares. Uma biblioteca enriquecida em motivos repetitivos foi construída e, após o seqüenciamento de aproximadamente 2000 clones, 600 microssatélites foram identificados e 134 locos desenvolvidos. Os marcadores mostraram tamanho reduzido com relação ao número de repetições e preponderância de motivos AC/GT. A aplicação dos microssatélites de D. mediopunctata para amplificações heterólogas em outras trinta espécies foi feita com aproximadamente 50% de sucesso. Em adição, o uso de dados de presença/ausência nas espécies do grupo tripunctata recuperou algumas relações filogenéticas previamente conhecidas. Um mapa de ligação foi construído com 49 marcadores e revelou 450 cM de extensão. Os cinco principais cromossomos da espécie foram identificados por meio de comparações com o genoma de D. melanogaster e com os elementos de Müller. Essas comparações também confirmaram a grande sintenia prevista dentro do gênero Drosophila. Não houve concordância na ordem dos locos microssatélites nas duas espécies. No cromossomo II de D. mediopunctata foi mapeada uma região associada à característica "número de pintas abdominais" / Abstract: Drosophila mediopunctata, a non-cosmopolitan fly of Neotropical distribution that belongs to the tripunctata group of the Drosophila subgenus, was chosen by some Brazilian researchers as a model in evolutionary studies. Several approaches, such as the analysis of natural variation and the influence of chromosome inversions in population dynamics, are traditionally used. Nevertheless, molecular markers, which would enhance the investigation of the genetic bases of the already known phenomena, are still not available for the species. Microsatellites are celebrated molecular markers and the chosen tool for the exploration of various organisms due to their ease of use. Nonetheless, their application in species whose genomes have not yet been sequenced requires a prior development phase. This study intended to develop, characterize and map microsatellites for the species D. mediopunctata so that initiatives concerning morphological variation, identification of genomic regions linked to interesting phenotypes, population genetics, etc can be carried out in the light of molecular data. A repetitive DNA-enriched library was constructed and approximately 2000 clones were sequenced. Six hundred microsatellites were identified and 134 loci were developed. The loci are small in length, with reduced number of motif repetitions, and are mainly composed of AC/GT dinucleotides. The use of D. mediopunctata microsatellites for heterologous amplification in other thirty Drosophila species was done with a 50% success ratio. In addition, a clustering analysis carried out with binary data obtained from the tripunctata species recovered already known phylogenetic relationships. A linkage map was constructed with recombination data of 49 markers and is 450 cM in length. The five major species chromosomes were identified on the basis of comparisons with the D. melanogaster genome and the Müller elements. This strategy also confirmed the great synteny predicted for the genus Drosophila. It was not observed agreement in loci order between both species. A genomic region associated to the number of abdominal spots was mapped to the chromosome II of D. mediopunctata / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular