27 resultados para Linkage-map

em Scielo Saúde Pública - SP


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Common bean (Phaseolus vulgaris) cultivars with a high degree of resistance to Xanthomonas axonopodis pv. phaseoli (Xap) are not available in Brazil. Despite many studies, a low degree of resistance to Xap continues to exist due to its complex genetic inheritance, which is not well known. The objectives of this research were to complement a common bean genetic map based on the cross between a susceptible genotype 'HAB-52' and a resistant genotype 'BAC-6', and to map and analyze genomic regions (quantitative trait loci – QTLs) related to Xap resistance. Eleven linkage groups were determined using 143 RAPD markers, covering 1,234.5 cM of the genome. This map was used to detect QTLs associated with Xap resistance on leaves and pods. The averages of disease severity on leaves (represented by the transformed disease index – TDI) and pods (represented by the diameter of lesion on pods – DLP) were added to the data of the linkage map. Five TDI QTLs and only one LDP QTL were detected. The TDI QTLs were placed in the A, B, G and J linkage groups, with phenotypic variations ranging from 12.7 to 71.6%. The DLP QTL explained 12.9% of the phenotypic variation and was mapped in a distinct linkage group. These results indicate that there are different genes involved in the control of resistance on leaves and pods.

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The objective of this work was to construct linkage maps of 'Pêra' sweet orange [Citrus sinensis (L.) Osbeck] and 'Cravo' mandarin (Citrus reticulata Blanco) using RAPD markers and the pseudo-testcross strategy. The parents were chosen according to the resistance/susceptibility to citrus variegate chlorosis (CVC). The segregation of 176 markers was analyzed in 94 progeny of F1 hybrids, which were obtained from controlled crossings. The linkage map of 'Pêra' sweet orange had 117 markers defined by 12 linkage groups, which spanned 612.1 cM. Only six markers could not be linked to the linkage group and 48.7% of the markers showed segregation distortion. The linkage map of 'Cravo' mandarin had 51 markers defined by 12 linkage groups, which spanned 353.3 cM. Only two markers did not link to the groups and 15.7% showed segregation distortion. The construction of linkage maps is relevant to future mapping studies of the inheritance of CVC, citrus canker and leprosis.

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The objective of this work was to select and use microsatellite markers, to map genomic regions associated with the genetic control of thermosensitive genic male sterility (TGMS) in rice. An F2 population, derived from the cross between fertile and TGMS indica lines, was used to construct a microsatellite-based genetic map of rice. The TGMS phenotype showed a continuous variation in the segregant population. A low level of segregation distortion was detected in the F2 (14.65%), whose cause was found to be zygotic selection. There was no evidence suggesting a cause-effect relationship between zygotic selection and the control of TGMS in this cross. A linkage map comprising 1,213.3 cM was constructed based on the segregation data of the F2 population. Ninety-five out of 116 microsatellite polymorphic markers were assembled into 11 linkage groups, with an average of 12.77 cM between two adjacent marker loci. The phenotypic and genotypic data allowed for the identification of three new quantitative trait loci (QTL) for thermosensitive genic male sterility in indica rice. Two of the QTL were mapped on chromosomes that, so far, have not been associated with the genetic control of the TGMS trait (chromosomes 1 and 12). The third QTL was mapped on chromosome 7, where a TGMS locus (tms2) has recently been mapped. Allelic tests will have to be developed, in order to clarify if the two regions are the same or not.

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The objectives of this study were to detect quantitative trait loci (QTL) for protein content in soybean grown in two distinct tropical environments and to build a genetic map for protein content. One hundred eighteen soybean recombinant inbred lines (RIL), obtained from a cross between cultivars BARC 8 and Garimpo, were used. The RIL were cultivated in two distinct Brazilian tropical environments: Cascavel county, in Paraná, and Viçosa county, in Minas Gerais (24º57'S, 53º27'W and 20º45'S, 42º52'W, respectively). Sixty-six SSR primer pairs and 65 RAPD primers were polymorphic and segregated at a 1:1 proportion. Thirty poorly saturated linkage groups were obtained, with 90 markers and 41 nonlinked markers. For the lines cultivated in Cascavel, three QTL were mapped in C2, E and N linkage groups, which explained 14.37, 10.31 and 7.34% of the phenotypic variation of protein content, respectively. For the lines cultivated in Viçosa, two QTL were mapped in linkage groups G and #1, which explained 9.51 and 7.34% of the phenotypic variation of protein content. Based on the mean of the two environments, two QTL were identified: one in the linkage group E (9.90%) and other in the group L (7.11%). In order for future studies to consistently detect QTL effects of different environments, genotypes with greater stability should be used.

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The present work aimed to characterize and identify QTLs for wood quality and growth traits in E. grandis x E. urophylla hybrids. For this purpose a RAPD linkage map was developed for the hybrids (LOD=3 and r=0.40) containing 52 markers and 12 linkage groups. Traits related to wood quality and growth were evaluated in the QTL analyses. QTL analyses were performed using chi-square tests, single-marker, interval mapping and composite interval mapping analyses. All approaches led to the identification of similar QTLs associated with wood density, cellulose pulp yield and percentage of extractives, which were detected and confirmed by both the interval mapping and composite interval mapping methodologies. Some QTLs regions were confirmed only by the composite interval mapping methodology: percentage of soluble lignin, percentage of insoluble lignin, CBH and total height. Overlapping QTLs regions were detected, and these, can be the result of major genes involved in the regulation and control of the growth traits by epistatic interactions. In order to evaluate the effect of early selection using RAPD molecular data, molecular markers adjacent to QTLs were used genotype selection. The analysis of selection differential values suggests that for all the traits the phenotypic selection at seven years should generate larger genetic gains than early selection assisted by molecular markers and the combination of the strategies should elevate the selection efficiency.

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Drosophila mediopunctata belongs to the tripunctata group, and is one of the commonest Drosophila species collected in some places in Brazil, especially in the winter. A standard map of the polytene chromosomes is presented. The breakpoints of the naturally occurring chromosomal rearrangements are marked on the map. The distribution of breaking points through the chromosomes of D. mediopunctata is apparently non-random. Chromosomes X, II and IV show inversion polymorphisms. Chromosome II is the most polymorphic, with 17 inversions, 8 inversions in the distal region and 9 in the proximal region. Chromosome X has four different gene arrangements, while chromosome IV has only two.

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Dense molecular genetic maps are used for an efficient quantitative trait loci (QTL) mapping and in the marker-assisted selection programs. A dense genetic map was generated with 139 microsatellite markers using 256 F2 plants generated by the crossing of two tropical maize inbred lines (L-02-03D and L-20-01F). This map presented 1,858.61 cM in length, where 10 linkage groups were found spanned, with an average interval of 13.47 cM between adjacent markers. Seventy seven percent of the maize genetic mapping bins were covered, which means an increase of 14% coverage in relation to the previous tropical maize maps. The results provide a more detailed and informative genetic map in a tropical maize population representing the first step to make possible the studies of genetic architecture to identify and map QTL and estimate their effects on the variation of quantitative traits, thus allowing the manipulation and use in tropical maize breeding programs.

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Discute-se o uso da "linkage" dos Sistemas Oficiais de Informação de Nascido Vivo (SINASC) e de Óbitos (SIM) em estudos de mortalidade neonatal. Essa técnica baseia-se na "ligação" dos bancos de dados obtidos a partir das informações existentes nesses sistemas, o que possibilita o emprego de estudos do tipo de coorte. O estudo foi realizado no Município de Santo André, Região Metropolitana de São Paulo, Brasil. São apresentados os cuidados metodológicos que foram empregados para evitar a presença de viéses de seleção e de efeito, que podem ocorrer. O uso da "linkage" mostrou-se operacionalmente viável, permitindo obter as probabilidades de morte e os riscos relativos dos nascidos vivos, expostos e não expostos, às variáveis que são objeto de registro na declaração de nascido vivo, identificando-se, desta maneira, os recém-nascidos de risco. Essa técnica, de baixo custo operacional, visto que utiliza dados já registrados, permite um dimensionamento mais adequado da assistência pré-natal e ao parto.

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OBJECTIVE: To evaluate the potential advantages and limitations of the use of the Brazilian hospital admission authorization forms database and the probabilistic record linkage methodology for the validation of reported utilization of hospital care services in household surveys. METHODS: A total of 2,288 households interviews were conducted in the county of Duque de Caxias, Brazil. Information on the occurrence of at least one hospital admission in the year preceding the interview was obtained from a total of 10,733 household members. The 130 records of household members who reported at least one hospital admission in a public hospital were linked to a hospital database with 801,587 records, using an automatic probabilistic approach combined with an extensive clerical review. RESULTS: Seventy-four (57%) of the 130 household members were identified in the hospital database. Yet only 60 subjects (46%) showed a record of hospitalization in the hospital database in the study period. Hospital admissions due to a surgery procedure were significantly more likely to have been identified in the hospital database. The low level of concordance seen in the study can be explained by the following factors: errors in the linkage process; a telescoping effect; and an incomplete record in the hospital database. CONCLUSIONS: The use of hospital administrative databases and probabilistic linkage methodology may represent a methodological alternative for the validation of reported utilization of health care services, but some strategies should be employed in order to minimize the problems related to the use of this methodology in non-ideal conditions. Ideally, a single identifier, such as a personal health insurance number, and the universal coverage of the database would be desirable.

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O objetivo do estudo foi avaliar a sensibilidade do método de linkage probabilístico de registros na identificação de nascimentos de coorte. Foram utilizados dados da população do Estudo Pró-Saúde, um estudo com funcionários técnico-administrativos do quadro efetivo de uma universidade no Rio de Janeiro, realizado em 1999. Os registros de 92 participantes foram relacionados com a base do Sistema de Informação sobre Nascidos Vivos utilizando o programa RecLink II. Empregaram-se estratégias de revisão manual reduzida e ampliada. A sensibilidade para a identificação dos nascimentos na estratégia reduzida foi de 60,9%, enquanto que na ampliada foi de 72,8%. Os poucos campos disponíveis e a elevada proporção de homônimas representaram os maiores obstáculos para a obtenção de resultados mais acurados.

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OBJETIVO: Analisar a subnotificação da comorbidade tuberculose (TB) e aids. MÉTODOS: Estudo de vigilância utilizando os registros do Sistema de Informação de Agravos de Notificação de Tuberculose e de aids no Brasil de 2000 a 2005. Registros de TB sem informação da presença de aids foram considerados subnotificações da comorbidade quando pareados a registros de aids que apresentassem ano de diagnóstico de aids igual ou anterior ao ano de notificação da TB, assim como os registros de um mesmo paciente cujos registros anteriores apresentavam essa informação. Criou-se um indicador: comorbidade TB-aids reconhecida, a partir dos registros de TB com a informação de presença de aids. RESULTADOS: A subnotificação de TB-aids foi de 17,7%. Esse percentual variou entre estados. A incorporação dos registros subnotificados aos previamente reconhecidos elevou a proporção de TB-aids no Brasil de 6,9% para 8,4%. As maiores proporções de subnotificação foram observadas no Acre, Alagoas, Maranhão e Piauí (mais de 35% cada) e as menores em São Paulo e Goiás (cerca de 10% cada). CONCLUSÕES: A subnotificação da comorbidade TB-aids encontrada no Brasil deve deflagrar modificações no sistema de vigilância para prover informações aos programas nacionais.

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One of the first scientific maps of the Amazon region, The Course of the Amazon River (Le Cours de La Rivière des Amazones), was constructed by Nicolas Sanson, a French cartographer of the seventeenth century, and served as the prototype for many others. The evaluation of this chart, until now, has been that it is a very defective map, a sketch based on a historical account, according to the opinion of La Condamine. Thus, the aim of the present work was to prove that the map of the Amazon River traced by Nicolas Sanson is a scientific work, a map that presents precise geographic coordinates considering its time, shows a well-determined prime meridian, and also employs a creative methodology to deduce longitudes from latitudes and distances that had been covered. To show such characteristics, an analysis of the accuracy of the map was made by comparing its latitudes and longitudes with those of a current map. We determined the prime meridian of this map and analyzed the methodology used for the calculation of longitudes. The conclusion is that it is actually a good map for the time, particularly considering the technology and the limited information that Sanson had at his disposal. This proves that the negative assertion of La Condamine is unfounded.

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By using improved pulsed field gel electrophoresis conditions, the molecular karyotype of the reference clone CL Brener selected for Trypanosoma cruzi genome project was established. A total of 20 uniform chromosomal bands ranging in size from 0.45 to 3.5 Megabase pairs (Mbp) were resolved in a single run. The weighted sum of the chromosomal bands was approximately 87 Mbp. Chromoblots were hybridized with 39 different homologous probes, 13 of which identified single chromosomes. Several markers showed linkage and four different linkage groups were identified, each comprising two markers. Densitometric analysis suggests that most of the chromosomal bands contain two or more chromosomes representing either homologous chromosomes and/or heterologous chromosomes with similar sizes

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Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease

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AbstractOBJECTIVEDescribing the profile of victims and assaults by gunshot, where the outcome was death.METHODAn ecological study conducted in the city of Maceió/AL, in 2012. Data were collected from the death statements. The variables studied were: the death circumstances, gender, age, marital status, place, date, time, month and proportion according to the occurring neighborhood.RESULTSThe homicide mortality rate was 65.2 per 100,000 inhabitants, with 130.6 per 100,000 men and 7.8 per 100,000 women. Of the total number of homicides, 93.6% of the victims were men. The age group between 15 and 29 years of age was the most affected, with 68.8%. In 97.6% of cases the death occurred at the site of aggression, 74.1% in the streets. In relation to the date, 54.2% of cases occurred between Friday and Sunday. 59.7% of the homicides were concentrated in seven neighborhoods.CONCLUSIONThe map of violence presented shows heterogeneous areas for the occurrence of assaults with firearms, characterizing the existing urban inequality in violence distribution.