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Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil

COLLET, Thais; CRISTINO, Alexandre Santos; QUIROGA, Carlos Fernando Prada; SOARES, Ademilson Espencer Egea; DEL LAMA, Marco Antônio
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
ENG
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35.87%
As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European.; FAPESP; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPq

COMPETITION AMONG EUCALYPTUS TREES DEPENDS ON GENETIC VARIATION AND RESOURCE SUPPLY

BOYDEN, Suzanne; BINKLEY, Dan; STAPE, Jose Luiz
Fonte: ECOLOGICAL SOC AMER Publicador: ECOLOGICAL SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Genetic variation and environmental heterogeneity fundamentally shape the interactions between plants of the same species. According to the resource partitioning hypothesis, competition between neighbors intensifies as their similarity increases. Such competition may change in response to increasing supplies of limiting resources. We tested the resource partitioning hypothesis in stands of genetically identical (clone-origin) and genetically diverse (seed-origin) Eucalyptus trees with different water and nutrient supplies, using individual-based tree growth models. We found that genetic variation greatly reduced competitive interactions between neighboring trees, supporting the resource partitioning hypothesis. The importance of genetic variation for Eucalyptus growth patterns depended strongly on local stand structure and focal tree size. This suggests that spatial and temporal variation in the strength of species interactions leads to reversals in the growth rank of seed-origin and clone-origin trees. This study is one of the first to experimentally test the resource partitioning hypothesis for intergenotypic vs. intragenotypic interactions in trees. We provide evidence that variation at the level of genes, and not just species, is functionally important for driving individual and community-level processes in forested ecosystems.; International Paper of Brazil; Brazil Eucalyptus Productivity Potential project; University of Sao Paulo in Piracicaba (USP/ESALQ); Colorado State University[DGE-0221595003]

The genetic diversity of Plasmodium malariae and Plasmodium brasilianum from human, simian and mosquito hosts in Brazil

Guimaraes, L. O.; Bajay, M. M.; Wunderlich, G.; Bueno, M. G.; Roehe, F.; Catao-Dias, J. L.; Neves, A.; Malafronte, R. S.; Curado, I.; Kirchgatter, K.
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Plasmodium malariae is a protozoan parasite that causes malaria in humans and is genetically indistinguishable from Plasmodium brasilianum, a parasite infecting New World monkeys in Central and South America. P. malariae has a wide and patchy global distribution in tropical and subtropical regions, being found in South America, Asia, and Africa. However, little is known regarding the genetics of these parasites and the similarity between them could be because until now there are only a very few genomic sequences available from simian Plasmodium species. This study presents the first molecular epidemiological data for P. malariae and P. brasilianum from Brazil obtained from different hosts and uses them to explore the genetic diversity in relation to geographical origin and hosts. By using microsatellite genotyping, we discovered that of the 14 human samples obtained from areas of the Atlantic forest, 5 different multilocus genotypes were recorded, while in a sample from an infected mosquito from the same region a different haplotype was found. We also analyzed the longitudinal change of circulating plasmodial genetic profile in two untreated non-symptomatic patients during a 12-months interval. The circulating genotypes in the two samples from the same patient presented nearly identical multilocus haplotypes (differing by a single locus). The more frequent haplotype persisted for almost 3 years in the human population. The allele Pm09-299 described previously as a genetic marker for South American P. malariae was not found in our samples. Of the 3 non-human primate samples from the Amazon Region...

Diversidade genética de isolados de xanthomonas axonopodis pv. passiflorae com base em marcadores rep-PCR e AFLP e construção de primers específicos para diagnose; Genetic diversity of Xanthomonas axonopodis pv. passiflorae isolates based on rep-PCR and AFLP markers and the construction of specific primers for diagnosis

Munhoz, Carla de Freitas
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/04/2009 PT
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O patógeno Xanthomonas axonopodis pv. passiflorae causa a mancha oleosa ou bacteriose do maracujazeiro, uma doença que acarreta prejuízos à cultura em decorrência da baixa produção de frutos, podendo causar a morte das plantas. Uma coleção de 87 isolados deste patovar, oriundos de 22 cidades dos Estados de São Paulo, Minas Gerais e Paraná e do Distrito Federal, foi usada para estudar a diversidade genética por rep-PCR e AFLP. Nove isolados de outros patovares foram incluídos nas análises genéticas. A técnica rep-PCR revelou pouca diversidade entre os isolados do patovar passiflorae, mas diferenciou, claramente, os diferentes patovares. Todavia, a técnica AFLP revelou considerável diversidade genética entre os isolados do patovar passiflorae. A análise molecular da variância mostrou que a maior parte da diversidade (49,4%) se encontra entre as cidades de coleta. O agrupamento gerado com base nos coeficientes de similaridade e os resultados do teste de atribuição pelo programa Structure revelaram clusters genotípicos homogêneos. Isto evidencia que a variação está mais associada à geografia, ou seja, às cidades de coleta, e que o fluxo desses isolados é pequeno. Cinco conjuntos de primers foram desenhados para a detecção do patógeno em plantas. Desses...

Genetic polymorphism, molecular characterization and relatedness of Macrobrachium species (Palaemonidae) based on RAPD-PCR.

Guerra, A. L.; Lima, A. V.; Taddei, F. G.; Castiglioni, L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 2317-2327
ENG
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The prawn genus Macrobrachium belongs to the family Palaemonidae. Its species are widely distributed in lakes, reservoirs, floodplains, and rivers in tropical and subtropical regions of South America. Globally, the genus Macrobrachium includes nearly 210 known species, many of which have economic and ecological importance. We analyzed three species of this genus (M. jelskii, M. amazonicum and M. brasiliense) using RAPD-PCR to assess their genetic variability, genetic structure and the phylogenetic relationship between them and to look for molecular markers that enable separation of M. jelskii and M. amazonicum, which are closely related syntopic species. Ten different random decamer primers were used for DNA amplification, yielding 182 fragments. Three of these fragments were monomorphic and exclusive to M. amazonicum or M. jelskii and can be used as specific molecular markers to identify and separate these two species. Similarity indices and a phylogenetic tree showed that M. amazonicum and M. jelskii are closest to each other, while M. brasiliense was the most differentiated species among them; this may be attributed to the different habitat conditions to which these species have been submitted. This information will be useful for further studies on these important crustacean species.

Assessment of genetic diversity in the Russian olive (Elaeagnus angustifolia) based on ISSR genetic markers

Asadiar,Leila Sadat; Rahmani,Fatemeh; Siami,Abbas
Fonte: Universidade Federal do Ceará Publicador: Universidade Federal do Ceará
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
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Elaeagnus is a Eurasian tree with 77 species worldwide. In this study, ISSR markers were used to establish the level of genetic relationships and polymorphism across nine genotypes of Elaeagnus angustifolia collected from 9 different regions of West Azarbaijan province. The ISSR analysis with 11 anchored primers also generated 116 scorable loci, of which 92 were polymorphic (79.3%). The estimated Jaccard similarity coefficient ranged from 0.44 to 0.76 for the ISSR markers. Cluster analysis was carried out, based on the Unweighted Pair Group Method with Arithmetic Averages (UPGMA) and the dendrogram drawn with the help of the NTSYSpc 2.02 software. The analysis revealed 5 main clusters for the ISSR data. According to our results, there is a relatively high genetic distance across E. angustifolia genotypes in the West Azarbaijan province of Iran. Furthermore, it could be inferred that ISSR markers are suitable tools for the evaluation of genetic diversity and relationships within the Elaeagnus genus.

Genetic structure of a lotic population of Burkolderia (Pseudomonas) cepacia.

Wise, M G; Shimkets, L J; McArthur, J V
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1995 EN
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The genetic structure of a population of Burkholderia (Pseudomonas) cepacia isolated from a southeastern blackwater stream was investigated by using multilocus enzyme electrophoresis to examine the allelic variation in eight structural gene loci. Overall, 213 isolates were collected at transect points along the stream continuum, from both the sediments along the bank and the water column. Multilocus enzyme electrophoresis analysis revealed 164 distinct electrophoretic types, and the mean genetic diversity of the entire population was 0.574. Genetic diversity values did not vary spatially along the stream continuum. From a canonical discriminant analysis, Mahalonobis distances (measurements of genetic similarity between populations) revealed significant differences among the subpopulations at the sediment sampling points, suggesting bacterial adaptation to a heterogeneous (or patchy) microgeographical environment. Multilocus linkage disequilibrium analysis of the isolates revealed only limited association between alleles, suggesting frequent recombination, relative to binary fission, in this population. Furthermore, the dendrogram created from the data of this study and the allele mismatch distribution are typical of a population characterized by extensive genetic mixing. We suggest that B. cepacia be added to the growing list of bacteria that are not obligatorily clonal.

Evolutionary Divergence of the Genetic Architecture Underlying Photoperiodism in the Pitcher-Plant Mosquito, Wyeomyia Smithii

Lair, K. P.; Bradshaw, W. E.; Holzapfel, C. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1997 EN
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We determine the contribution of composite additive, dominance, and epistatic effects to the genetic divergence of photoperiodic response along latitudinal, altitudinal, and longitudinal gradients in the pitcher-plant mosquito, Wyeomyia smithii. Joint scaling tests of crosses between populations showed wide-spread epistasis as well as additive and dominance differences among populations. There were differences due to epistasis between an alpine population in North Carolina and populations in Florida, lowland North Carolina, and Maine. Longitudinal displacement resulted in differences due to epistasis between Florida and Alabama populations separated by 300 km but not between Maine and Wisconsin populations separated by 2000 km. Genetic differences between New Jersey and Ontario did not involve either dominance or epistasis and we estimated the minimum number of effective factors contributing to a difference in mean critical photoperiod of 5 SD between them as n(E) = 5. We propose that the genetic similarity of populations within a broad northern region is due to their more recent origin since recession of the Laurentide Ice Sheet and that the unique genetic architecture of each population is the result of both mutation and repeated migration-founder-flush episodes during the dispersal of W. smithii in North America. Our results suggest that differences in composite additive and dominance effects arise early in the genetic divergence of populations while differences due to epistasis accumulate after more prolonged isolation.

Analysis of Microsatellite DNA Markers Reveals no Genetic Differentiation between Wild and Hatchery Populations of Pacific Threadfin in Hawaii

Pan, Gang; Yang, Jinzeng
Fonte: Ivyspring International Publisher Publicador: Ivyspring International Publisher
Tipo: Artigo de Revista Científica
Publicado em 15/12/2010 EN
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Pacific threadfin, Polydactylus sexfilis, is popular fish in recreational fishing, as well as aquaculture in Hawaii. Its natural population has been continuously declining in the past several decades. Microsatellite DNA markers are useful DNA-based tool for monitoring Pacific threadfin populations. In this study, fifteen Microsatellite (MS) DNA markers were identified from a partial genomic Pacific threadfin DNA library enriched in CA repeats, and six highly-polymorphic microsatellite loci were employed to analyze genetic similarity and differences between the wild population and hatchery population in Oahu Island. A total of 37 alleles were detected at the six MS loci in the two populations. Statistical analysis of fixation index (FST) and analysis of molecular variance (AMOVA) showed no genetic differentiation between the wild and hatchery populations (FST=0.001, CI95%= -0.01-0.021). Both high genetic diversity (Ho=0.664-0.674 and He=0.710-0.715) and Hardy-Weinberg equilibrium were observed in the wild and hatchery populations. Results of genetic bottleneck analysis indicated that the hatchery was founded with sufficient numbers of brooders as inbreeding coefficient is very low (FIS=0.052-0.072) in both wild and hatchery populations. Further studies are needed for comprehensive determinations of genetic varieties of primary founder broodstocks and successive offspring of the hatchery and wild populations with increased number of Pacific threadfin sample collections.

Investigating Concordance among Genetic Data, Subspecies Circumscriptions and Hostplant Use in the Nymphalid Butterfly Polygonia faunus

Kodandaramaiah, Ullasa; Weingartner, Elisabet; Janz, Niklas; Leski, Michael; Slove, Jessica; Warren, Andrew; Nylin, Sören
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 23/07/2012 EN
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Subspecies are commonly used taxonomic units to formally describe intraspecific geographic variation in morphological traits. However, the concept of subspecies is not clearly defined, and there is little agreement about what they represent in terms of evolutionary units, and whether they can be used as reliably useful units in conservation, evolutionary theory and taxonomy. We here investigate whether the morphologically well-characterized subspecies in the North American butterfly Polygonia faunus are supported by genetic data from mitochondrial sequences and eight microsatellite loci. We also investigate the phylogeographic structure of P. faunus and test whether similarities in host-plant use among populations are related to genetic similarity. Neither the nuclear nor the mitochondrial data corroborated subspecies groupings. We found three well defined genetic clusters corresponding to California, Arizona and (New Mexico+Colorado). There was little structuring among the remaining populations, probably due to gene flow across populations. We found no support for the hypothesis that similarities in host use are related to genetic proximity. The results indicate that the species underwent a recent rapid expansion, probably from two glacial refugia in western North America. The mitochondrial haplotype network indicates at least two independent expansion phases into eastern North America. Our results clearly demonstrate that subspecies in P. faunus do not conform to the structuring of genetic variation. More studies on insects and other invertebrates are needed to better understand the scope of this phenomenon. The results of this study will be crucial in designing further experiments to understand the evolution of hostplant utilization in this species.

Genetic ancestry inference using support vector machines, and the active emergence of a unique American population

Haasl, Ryan J; McCarty, Catherine A; Payseur, Bret A
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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We use genotype data from the Marshfield Clinical Research Foundation Personalized Medicine Research Project to investigate genetic similarity and divergence between Europeans and the sampled population of European Americans in Central Wisconsin, USA. To infer recent genetic ancestry of the sampled Wisconsinites, we train support vector machines (SVMs) on the positions of Europeans along top principal components (PCs). Our SVM models partition continent-wide European genetic variance into eight regional classes, which is an improvement over the geographically broader categories of recent ancestry reported by personal genomics companies. After correcting for misclassification error associated with the SVMs (<10%, in all cases), we observe a >14% discrepancy between insular ancestries reported by Wisconsinites and those inferred by SVM. Values of FST as well as Mantel tests for correlation between genetic and European geographic distances indicate minimal divergence between Europe and the local Wisconsin population. However, we find that individuals from the Wisconsin sample show greater dispersion along higher-order PCs than individuals from Europe. Hypothesizing that this pattern is characteristic of nascent divergence, we run computer simulations that mimic the recent peopling of Wisconsin. Simulations corroborate the pattern in higher-order PCs...

Genetic structure and gene flow of Eugenia dysenterica natural populations.

ZUCCHI, M. I.; PINHEIRO, J. B.; CHAVES. L. J.; COELHO, A. S. G.; COUTO, M. A.; MOAIS, L. K. de; VENCOVSKY, R.
Fonte: Pesquisa Agropecuária Brasileira, Brasília, v.40, n. 10, p. 975-980, out. 2005. Publicador: Pesquisa Agropecuária Brasileira, Brasília, v.40, n. 10, p. 975-980, out. 2005.
Tipo: Artigo em periódico indexado (ALICE)
EN
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This study was carried out to assess the genetic variability of ten "cagaita" tree (Eugenia dysenterica) populations in Southeastern Goiás. Fifty-four randomly amplified polymorphic DNA (RAPD) loci were used to characterize the population genetic variability, using the analysis of molecular variance (AMOVA). A fST value of 0.2703 was obtained, showing that 27.03% and 72.97% of the genetic variability is present among and within populations, respectively. The Pearson correlation coefficient (r) among the genetic distances matrix (1 - Jaccard similarity index) and the geographic distances were estimated, and a strong positive correlation was detected. Results suggest that these populations are differentiating through a stochastic process, with restricted and geographic distribution dependent gene flow.; 2005

Algoritmo genético de agrupamento para formação de módulos de arranjo físico; A clustering genetic algorithm for the formation of facility layout modules

Argoud, Ana Rita Tiradentes Terra; GONÇALVES FILHO, Eduardo Vila; Tiberti, Alexandre José
Fonte: Universidade Federal de São Carlos Publicador: Universidade Federal de São Carlos
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
35.88%
O projeto de arranjo físico modular tem como base o agrupamento de máquinas em módulos a partir de subseqüências de operações comuns a um conjunto de peças. No método proposto por Huang (2003), os módulos de arranjo físico são gerados por análise de agrupamentos. O presente trabalho apresenta uma forma alternativa à geração de módulos de arranjo físico, através de algoritmo genético de agrupamento (AGA). O AGA permite ao usuário especificar a priori o número desejado de módulos (problema de K-agrupamentos), e também trabalhar de forma que o número e a formação dos módulos sejam variáveis de decisão do problema (problema de agrupamento automático). Uma característica importante do AGA é sua flexibilidade, pois fornece a possibilidade ao usuário de interagir com o método de solução através da escolha de diferentes codificações do cromossomo, de medidas de similaridade para comparação de seqüências de operações e de métodos de geração da nova população. Para tal foram desenvolvidos dois operadores de cruzamento e três operadores de mutação. No exemplo apresentado, os módulos de arranjo físico gerados pelo AGA e o arranjo físico final da fábrica foram comparados aos de Huang (2003) e houve importante redução da distância total percorrida pelo conjunto de peças...

Assessment of the genetic diversity of the pinewood nematode, Bursaphelenchus xylophilus, in Portugal; Avaliação da diversidade genética do nemátode da madeira do pinheiro, Bursaphelenchus xylophilus, em Portugal

Vieira, Paulo Cezanne Reis
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Dissertação de Mestrado
ENG
Relevância na Pesquisa
35.88%
O nemátode da madeira do pinheiro (NMP), Bursaphelenchus xylophiius, tem uma extensa distribuição na América do Norte, e encontra-se atualmente distribuído ao longo da maioria dos territórios de Canadá e dos Estados Unidos. Durante o último século, esta espécie foi transportada pelo Homem para outras regiões do mundo (não-nativas), associadas com o comércio e o fluxo global de produtos de origem florestal. Atualmente, esta espécie invasiva está reportada para algumas regiões do SE asiático (China, Japão, Coreia e Taiwan) e mais recentemente para a Europa (Portugal). Devido ao impacto que este organismo agente da doença da murchidão dos pinheiros causa nas florestas nativas destas regiões esta espécie assume uma elevada importância económica a nível mundial Em Portugal, a distribuição do NMP encontra-se confinada a uma área restrita e limitada (500 000 ha), a sul de Lisboa (península de Setúbal); contudo, constitui uma das maiores ameaças às florestas de pinheiro do país e da UE. Ate recentemente, nenhum consenso existia quanto à origem do NMP em Portugal. Diversas hipóteses têm sido colocadas para explicar esta introdução, nomeadamente a partir de zonas onde o nematode ocorre naturalmente (América do Norte)...

Genetic diversity in table grapes based on RAPD and microsatellite markers

Leão,Patrícia Coelho de Souza; Motoike,Sérgio Yoshimitsu
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
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The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair‑group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.

Genetic diversity in table grapes based on RAPD and microsatellite markers.

LEAO, P. C. de S.; MOTOIKE, S. Y.
Fonte: Pesquisa agropecuária Brasileira, Brasília, v.46, n.9, p.1035-1044, set. 2011 Publicador: Pesquisa agropecuária Brasileira, Brasília, v.46, n.9, p.1035-1044, set. 2011
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
35.88%
The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair-group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.; 2011

Genetic diversity for gliadin patterns of durum wheat landraces in the Northwest of Iran and Azerbaijan.

ZAEFIZDAH, M.; JAMAATI-E-SOMARIN, S.; OJAGHI, J.; SEYEDI, S. M.; ZABIHI-E-MAHMOODABAD, R.; OCHI, M.
Fonte: Pesquisa Agropecuaria brasileira., Brasília, v.45, n.12, p.1425-1432, dez. 2010 Publicador: Pesquisa Agropecuaria brasileira., Brasília, v.45, n.12, p.1425-1432, dez. 2010
Tipo: Artigo em periódico indexado (ALICE)
EN
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Abstract ? The objective of this study was to identify gliadin band patterns and the extent of genetic diversity in durum wheat genotypes from Northwestern Iran and the Republic of Azerbaijan. Gliadins from 46 landraces and four cultivars were evaluated through acid PAGE analyses. Sixty-six polymorphic bands and 81 patterns were identified. Twenty-four different motility bands and 22 patterns were found in the ? gliadin region with 14 polymorph bands and 20 patterns for ? and ? gliadins, and 14 bands and 19 different patterns for ? gliadins. The combination of these patterns generated 38 and 39 combinations for Gli-1 and Gli-2 loci, respectively. The genetic diversity index (H) was higher for ? gliadins (0.924), followed by ? and ? gliadins (0.899 and 0.878, respectively), and for ? gliadin patterns (0.866). Extensive polymorphism (H = 0.875) was observed in four gliadin pattern regions, with higher genetic diversity in the Iranian landraces than in the Azerbaijani ones. Each genotype had special identifying patterns in the gliadin acid PAGE analysis, and cluster analysis based on Jaccard's similarity coefficients formed six groups. Gliadin has a simple, repeatable and economic analysis, and can be used in genetic studies.; 2010

Genetic affinities of Jewish populations.

Livshits, G; Sokal, R R; Kobyliansky, E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1991 EN
Relevância na Pesquisa
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Genetic relations between various Jewish (J) and non-Jewish (NJ) populations were assessed using two sets of data. The first set contained 12 pairs of matched J and NJ populations from Europe, the Middle East, and North Africa, for which 10 common polymorphic genetic systems (13 loci) were available. The second set included 22 polymorphic genetic systems (26 loci) with various numbers of populations (ranging from 21 to 51) for each system. Therefore, each system was studied separately. Nei's standard genetic distance (D) matrices obtained for these two sets of data were tested against design matrices specifying hypotheses concerning the affiliations of the tested populations. The tests against single designs were carried out by means of Mantel tests. Our results consistently show lower distances among J populations than with their NJ neighbors, most simply explained by the common origin of the former. Yet, there is evidence also of genetic similarity between J and corresponding NJ populations, suggesting reciprocal gene flow between these populations or convergent selection in a common environment. The results of our study also indicate that stochastic factors are likely to have played a role in masking the descent relationships of the J populations.

A general decision framework for structuring computation using Data Directional Scaling to process massive similarity matrices

Lawson, Daniel John; Adams, Niall M
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 17/03/2014
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As datasets grow it becomes infeasible to process them completely with a desired model. For giant datasets, we frame the order in which computation is performed as a decision problem. The order is designed so that partial computations are of value and early stopping yields useful results. Our approach comprises two related tools: a decision framework to choose the order to perform computations, and an emulation framework to enable estimation of the unevaluated computations. The approach is applied to the problem of computing similarity matrices, for which the cost of computation grows quadratically with the number of objects. Reasoning about similarities before they are observed introduces difficulties as there is no natural space and hence comparisons are difficult. We solve this by introducing a computationally convenient form of multidimensional scaling we call `data directional scaling'. High quality estimation is possible with massively reduced computation from the naive approach, and can be scaled to very large matrices. The approach is applied to the practical problem of assessing genetic similarity in population genetics. The use of statistical reasoning in decision making for large scale problems promises to be an important tool in applying statistical methodology to Big Data.; Comment: 30 pages...

Genetic variability among _Coleus sp_ studied by RAPD banding pattern analysis

Muthusamy Govarthanan; Arunapriya S; Guruchandar A; Selvankumar T; Gnanasekaran N; Manoharan Koildhasan
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
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Genetic improvement of the medicinal plants depends upon the existence, nature and extent of the genetic variability available for manipulation. Genetic analysis with RAPD markers has been extensively used to determine genetic diversity among _Coleus sp_ and to identify the best quality for human consumption for its medicinal purpose. The objectives of the present study were to assess molecular variation among _C.amboinicus_, _C.aromaticus_ and _C.forskohlii_. and to determine the level of genetic similarity among them. We performed random amplification of polymorphic DNA (RAPD) analysis on three strains of _Coleus sp_. Random primers were used for the PCR. Electrophoresis on denaturing acrylamide gels improved RAPD reproducibility and increased the band number. The primer OPW 6 and OPW 7 gave reproducible results and the band profiles.