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Genetic analysis of forest species Eugenia uniflora L. through of newly developed SSR markers

FERREIRA-RAMOS, Ronai; LABORDA, Prianda R.; SANTOS, Melissa de Oliveira; MAYOR, Matheus S.; MESTRINER, Moacyr A.; SOUZA, Anete P. de; ALZATE-MARIN, Ana Lilia
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
55.71%
Nine microsatellite loci for genetic analysis of three populations of the tropical tree Eugenia uniflora L. (pitanga or Brazilian cherry) from fragments of semideciduous forest were developed. We used the technique of building a (GA)(n) and (CA)(n) microsatellite-enriched library by capture with streptavidin-coated magnetic beads. We assessed the polymorphism of seven microsatellites in 84 mature trees found in three areas (Ribeir (a) over tildeo Preto, Tambau and S (a) over tildeo Jose do Rio Pardo), highly impacted by the agricultural practices, in a large region among Pardo river and Mogi-Guacu river basins, in state of S (a) over tildeo Paulo, Brazil. All loci were polymorphic, and the number of alleles was high, ranging from 6 to 24, with a mean of 14.4. All stands showed the same high level of genetic diversity (mean H(E) = 0.83) and a low genetic differentiation (mean F(ST) = 0.031), indicating that genetic diversity was higher within rather than among populations. Seven of the nine loci were highly variable, and sufficiently informative for E. uniflora. It was concluded that these new SSR markers can be efficiently used for gene flow studies.; Sao Paulo State Government[03/04199-4/2004]; Sao Paulo University (USP); FAPESP

Uso do delineamento III com marcadores moleculares para a análise genética da produção de grãos e seus componentes em milho.; Use of the design III with molecular markers for the genetic analysis of grain yield and its components in maize.

Aguiar, Aurelio Mendes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/11/2003 PT
Relevância na Pesquisa
65.77%
O delineamento III foi proposto para estimar as variâncias aditivas e de dominância e o grau médio de dominância de caracteres quantitativos. Com o advento dos marcadores moleculares, Cockerham & Zeng (1996) desenvolveram uma metodologia genético-estatística associando o delineamento III com marcadores moleculares. Esta metodologia foi proposta visando estimar, com o uso de quatro contrastes ortogonais, os efeitos aditivos, dominantes e epistáticos dos QTLs ligados a marcadores moleculares. O objetivo desta pesquisa foi usar ambas as metodologias para análise genética da produção de grãos, componentes da produção e número de ramificações do pendão em uma população referência F2 de milho. Duzentos e cinqüenta progênies F2:3 foram retrocruzadas com ambas linhagens genitoras, dando origem a 500 progênies de retrocruzamento. Estas progênies foram alocadas em cinco látices 10x10 e avaliadas em seis ambientes em três estações experimentais próximas a Piracicaba, SP, com duas repetições por ambientes. Estimativas de variância aditiva e de dominância, assim como o grau médio de dominância dos caracteres avaliados, apresentaram magnitudes similares às reportadas em populações de milho temperado para todos os caracteres. Estimativas do grau médio de dominância foram inferiores a um para o diâmetro da espiga...

Modelos de regressão aleatória usando como bases as funções polinomiais de Legendre, de Jacobi modificadas e trigonométricas, com uma aplicação na análise genética dos pesos de bovinos da raça Nelore; Random coefficient regression models using the Legendre polynomials, modified Jacobi polynomials and trigonometric functions as bases, with an application to genetic analysis of the weight of cattle from the Nellore breed

Macedo, Osmar Jesus
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/11/2007 PT
Relevância na Pesquisa
55.74%
Com o objetivo de avaliar o desempenho dos modelos mistos quando se assumem bases de funções ortonormais de Legendre, Jacobi modificadas e trigonométricas como covariáveis dos coeficientes aleatórios, os dados referentes à pesagem corporal de animais da raça Nelore do nascimento aos 800 dias, foram analisados com modelos que assumiram inicialmente coeficientes aleatórios de efeito genético direto e efeito permanente animal (dois fatores aleatórios), em seguida foi acrescentado o efeito genético materno (três fatores aleatórios) e finalmente assumiram-se também os coeficientes aleatórios de efeito permanente materno (quatro fatores aleatórios). Foram considerados como efeitos fixos, as idades da mãe ao parto, os grupos contemporâneos e uma regressão linear por polinômios de Legendre. Os dados oriundos da fazenda Mundo Novo fornecidos pelo Grupo de Melhoramento Animal da FZEA/USP continham 61.975 pesagens corporais de 20.543 animais e informações de 26.275 animais da raça Nelore no "pedigree". O número de pesagem por animal não ultrapassou a seis e cada animal forneceu apenas uma medida em cada um dos seguintes intervalos de idade (em dias): 1 – 69, 70 – 159, 160 – 284, 285 – 454, 455 – 589 e 590 – 800. O propósito desse estudo foi comparar o ajuste da curva média de crescimento dos animais por intermédio de modelos mistos sob influência das funções ortonormais com dois...

Análise filogenética de diferentes populações do carrapato Rhipicephalus sanguineus provenientes de diferentes regiões do Brasil, da América Latina, Espanha, Itália e África do Sul; Genetic Analysis of different populations of Rhipicephalus sanguineus from Brazil, Latin America, Spain, Italy and South Africa

Moraes-Filho, Jonas
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 26/02/2010 PT
Relevância na Pesquisa
55.64%
Dentro do gênero Rhipicephalus, há o chamado complexo sanguineus formado por várias espécies presentes apenas no Velho Mundo, das quais apenas a espécie Rhipicephalus sanguineus é considerada de ocorrência no Novo Mundo. Como as espécies deste complexo apresentam grande similaridade morfológica, é possível que mais de uma espécie do complexo sanguineus esteja ocorrendo nas Américas. Um trabalho recente relatou parâmetros biológicos e genéticos significativamente diferentes entre uma população de R. sanguineus do Brasil e outra da Argentina, sugerindo que o status biosistemático de R. sanguineus na América do Sul deva ser revisto. Diante disto, e da inquestionável importância medico-veterinária de R. sanguineus na América do Sul, este projeto objetivou realizar uma análise genética de 32 populações de R. sanguineus, sendo 17 do Brasil (englobando 13 estados), 3 do Chile, 2 da Venezuela, 2 da Colômbia e 1 de cada um dos seguintes países: Argentina, Uruguai, Itália, Espanha, África do Sul, Costa Rica, Panamá, México. Uma amostra de Rhipicephalus turanicus da Espanha e uma da África do sul também foram analisadas. Para tal, carrapatos oriundos das diferentes populações foram analisados geneticamente através de seqüências dos genes mitocondriais 16S rDNA. O resultado deste trabalho permitiu inferir sobre a possibilidade da existência no mínimo de dois grupos distintos de carrapatos sob o táxon R. sanguineus na América Latina...

Análises genéticas em sistemas microfabricados; Genetic analysis in microfabricated systems

Duarte, Gabriela Rodrigues Mendes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/07/2010 PT
Relevância na Pesquisa
65.78%
A produção de microssistemas de análises totais (µTAS) tem sido objeto de esforços intensos pela comunidade científica. A necessidade de produção de uma plataforma que realize extração, amplificação e separação de DNA--um verdadeiro "lab on a chip"--é impulsionada pelas vantagens associadas com as análises em plataformas miniaturizadas. Esta Tese foca no desenvolvimento de métodos para análises de DNA em dispositivos microfluídicos que podem ser associados em µTAS. Inicialmente, foi feito o desenvolvimento de um novo método de extração em fase sólida em que a eficiência de extração depende da manipulação magnética das partículas e não do fluxo da solução através da fase sólida. A utilidade desta técnica em isolar DNA puro de alta qualidade (amplificável) a partir de uma amostra biológica complexa foi demonstrada através da purificação de DNA a partir de sangue total e a subsequente amplificação do fragmento do gene β-globina. A técnica descrita é rápida, simples e eficiente, permitindo uma recuperação de mais de 60% de DNA a partir de 600 nL de sangue em concentração suficiente para amplificação via reação em cadeia da polimerase (PCR). Após o desenvolvimento da extração dinâmica de DNA em fase sólida (dSPE) em microchip de vidro...

Genetic analysis of protease and reverse transcriptase of HIV-1 from Southern Brazil naïve clinical isolates

Medeiros, Rubia Marília de
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
ENG
Relevância na Pesquisa
55.67%
Background: Rio Grande do Sul, the southernmost state of Brazil, presents an atypical epidemiological situation where HIV-1 subtype C co-circulates with subtypes B and CRF31_BC, contrasting with the other Brazilian regions were subtypes B and F dominates. These infections have been effectively managed with highly active antiretroviral therapy (HAART) since 1996. Objective: To evaluate the profile of mutations and polymorphisms in the protease and reverse transcriptase regions in diferent subtypes of HIV-1 from untreated patients living in Southern Brazil. Methods: Blood samples from 99 HIV-1 positive antiretroviral/drugs-naïve, which were not in drug therapy, were collected from 2005 to 2007, in Porto Alegre Brazil. Protease and reverse transcriptase genes were amplified, sequenced and subtyped through phylogenetic analyses. HIV strain genotyping was performed by partial pol sequence analysis with the HIV Drug Resistance Database of Stanford University. Results: Phylogenetic analyses of the 99 pol samples, were classified according their subtypes: B (26.2%), C (39.4%), F (1.1%), CRF31_CB (19.2%) and URF (14.1%). Eight (8.1%) samples showed primary resistance mutations to Calibrated Population Resistance tool based in the 2009 Surveillance Drug Resistance Mutation list. Two samples presented PI resistance mutations: I54T and I54L; two NRTI resistance mutation: D67G...

Genetic analysis of phosphoprotein and matrix protein of rabies viruses isolated in Brazil

Kobayashi, Yuki; Okuda, Hiromi; Nakamura, Kana; Sato, Go; Itou, Takuya; Carvalho, Adolorata A. B.; Silva, Marlon V.; Mota, Carla S.; Ito, Fumio H.; Sakai, Takeo
Fonte: Japan Soc Vet Sci Publicador: Japan Soc Vet Sci
Tipo: Artigo de Revista Científica Formato: 1145-1154
ENG
Relevância na Pesquisa
55.67%
To investigate the genetic characteristics of phosphoprotein (P) and matrix protein (M) genes of variable rabies virus (RV) prevalent in Brazil, the authors genetically characterized the P and M genes from 30 Brazilian RV field isolates. Phylogenetic analysis based on the P and M genes revealed the presence of six RV variants that consisted primarily of three insectivorous bats, the vampire bat, dog and fox in Brazil. Specific amino acid substitutions corresponding to these phylogenetic lineages were observed, with ASP(42) and GlU(62) in the P protein found to be characteristic of Brazilian chiroptera- and carnivora-related RVs, respectively. Amino acid sequence motifs predicted to associate with a viral function in the P and M proteins were conserved among Brazilian RV variants.

Transferability and use of microsatellite markers for the genetic analysis of the germplasm of some Arachis section species of the genus Arachis

Bravo, Juliana Pereira; Hoshino, Andrea Akemi; Angelici, Carla Maria Lara C.D.; Lopes, Catalina Romero; Gimenes, Marcos Aparecido
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 516-524
ENG
Relevância na Pesquisa
55.79%
The Arachis section is the most important of the nine sections of the genus Arachis because it includes the cultivated peanut, Arachis hypogaea. The genetic improvement of A. hypogaea using wild relatives is at an early stage of development in spite of their potential as sources of genes, including those for disease and pests resistance, that are not found in the A. hypogaea primary gene pool. Section Arachis species germplasm has been collected and maintained in gene banks and its use and effective conservation depends on our knowledge of the genetic variability contained in this material. Microsatellites are routinely used for the analysis of genetic variability because they are highly polymorphic and codominant. The objective of this study was to evaluate the transferability of microsatellite primers and the assay of genetic variability between and within the germplasm of some species of the Arachis section. Fourteen microsatellite loci developed for three different species of Arachis were analyzed and 11 (78%) were found to be polymorphic. All loci had transferability to all the species analyzed. The polymorphic loci were very informative, with expected heterozygosity per locus ranging from 0.70 to 0.94. In general, the germplasm analyzed showed wide genetic variation. © 2006 Sociedade Brasileira de Genética.

Genetic analysis of forest species Eugenia uniflora L. through of newly developed SSR markers

FERREIRA-RAMOS, Ronai; LABORDA, Prianda R.; SANTOS, Melissa de Oliveira; MAYOR, Matheus S.; MESTRINER, Moacyr A.; SOUZA, Anete P. de; ALZATE-MARIN, Ana Lilia
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
55.71%
Nine microsatellite loci for genetic analysis of three populations of the tropical tree Eugenia uniflora L. (pitanga or Brazilian cherry) from fragments of semideciduous forest were developed. We used the technique of building a (GA)(n) and (CA)(n) microsatellite-enriched library by capture with streptavidin-coated magnetic beads. We assessed the polymorphism of seven microsatellites in 84 mature trees found in three areas (Ribeir (a) over tildeo Preto, Tambau and S (a) over tildeo Jose do Rio Pardo), highly impacted by the agricultural practices, in a large region among Pardo river and Mogi-Guacu river basins, in state of S (a) over tildeo Paulo, Brazil. All loci were polymorphic, and the number of alleles was high, ranging from 6 to 24, with a mean of 14.4. All stands showed the same high level of genetic diversity (mean H(E) = 0.83) and a low genetic differentiation (mean F(ST) = 0.031), indicating that genetic diversity was higher within rather than among populations. Seven of the nine loci were highly variable, and sufficiently informative for E. uniflora. It was concluded that these new SSR markers can be efficiently used for gene flow studies.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic analysis of Theileria Orientalis population in cattle following a theileriosis outbreak in Victoria, Australia

Cufos, Nádia Soraia Segredo Spiro
Fonte: Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária Publicador: Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária
Tipo: Dissertação de Mestrado
Publicado em //2012 ENG
Relevância na Pesquisa
55.72%
Dissertação de Mestrado Integrado em Medicina Veterinária; Bovine theileriosis is a tick-borne disease caused by one or more haemoprotozoan parasites of the genus Theileria. In the past, Theileria infection in cattle in Australia was largely asymptomatic and recognized to be associated with Theileria buffeli. However, in the recent years, outbreaks of theileriosis have occurred in beef and dairy cattle in subtropical climatic regions (New South Wales) of Australia. There is also one published report of a recent theileriosis outbreak on a beef farm near Seymour in the south-eastern state of Victoria. In order to gain an improved insight into the genetic composition of Theileria populations following this outbreak, we undertook herein an integrated PCR-coupled mutation scanning-sequencing-phylogenetic analysis of sequence variation in part of the major piroplasm surface protein (MPSP) gene within and among samples from cattle involved in the outbreak. Theileria DNA was detected in 89.4% of 94 cattle on the Seymour farm; the genetic analysis showed that the ikeda and chitose genotypes representing the Theileria orientalis complex were detected in 75% and 4.8% of 84 infected cattle, respectively, and that mixed populations of these two genotypes were found in 20.2% of infected cattle. Given unpublished reports of a significant increase in the number of outbreaks in Victoria...

Genetic analysis and gene fine mapping of aroma in rice (Oryza sativa L. Cyperales, Poaceae)

Sun,Shu Xia; Gao,Fang Yuan; Lu,Xian Jun; Wu,Xian Jun; Wang,Xu Dong; Ren,Guang Jun; Luo,Hong
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
55.62%
We investigated inheritance and carried out gene fine mapping of aroma in crosses between the aromatic elite hybrid rice Oryza sativa indica variety Chuanxiang-29B (Ch-29B) and the non-aromatic rice O. sativa indica variety R2 and O. sativa japonica Lemont (Le). The F1 grains and leaves were non-aromatic while the F2 non-aroma to aroma segregation pattern was 3:1. The F3 segregation ratio was consistent with the expected 1:2:1 for a single recessive aroma gene in Ch-29B. Linkage analysis between simple sequence repeat (SSR) markers and the aroma locus for the aromatic F2 plants mapped the Ch-29B aroma gene to a chromosome 8 region flanked by SSR markers RM23120 at 0.52 cM and RM3459 at 1.23 cM, a replicate F2 population confirming these results. Three bacterial artificial chromosome (BAC) clones cover chromosome 8 markers RM23120 and RM3459. Our molecular mapping data from the two populations indicated that the aroma locus occurs in a 142.85 kb interval on BAC clones AP005301 or AP005537, implying that it might be the same gene reported by Bradbury et al (2005a; Plant Biotec J. 3:363-370). The flanking markers Aro7, RM23120 and RM3459 identified by us could greatly accelerate the efficiency and precision of aromatic rice breeding programs.

Developmental genetic analysis of fruit shape traits under different environmental conditions in sponge gourd (Luffa cylindrical (L) Roem. Violales, Cucurbitaceae)

Zhang,Sheng; Hu,Jin; Xu,Shengchun
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
55.79%
Analysis of genetic main effects and genotype × environment (GE) interaction effects for the fruit shape traits fruit length and fruit circumference in the sponge gourd (Luffa cylindrical (L) Roem. Violales, Cucurbitaceae) was conducted for diallel cross data from two planting seasons. A genetic model including fruit direct effects and maternal effects and unconditional and conditional variances analysis was used to evaluate the development of the fruit at four maturation stages. The variance analysis results indicated that fruit length and circumference were simultaneously affected by fruit direct genetic effects and maternal effects as well as GE interaction effects. Fruit direct genetic effects were relatively more important for both fruit shape traits during the whole developmental period. Gene activation was mostly due to additive effects at the first maturation stage and dominance effects were mainly active during the other three stages. The fruit shape trait correlation coefficients due to different genetic effects and the phenotypic correlation coefficients varied significantly for the various maturation stages. The results indicate that it is relatively easy to improve the two fruit shape traits for market purposes by carefully selecting the parents at the first maturation stage 3 days after flowering instead of at fruit economic maturation.

Examining the efficacy of a genotyping-by-sequencing technique for population genetic analysis of the mushroom Laccaria bicolor and evaluating whether a reference genome is necessary to assess homology

Wilson, A. W.; Wickett, N. J.; Grabowski, P.; Fant, J.; Borevitz, J.; Mueller, G. M.
Fonte: Mycological Society of America Publicador: Mycological Society of America
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.73%
Given the diversity and ecological importance of Fungi, there is a lack of population genetic research on these organisms. The reason for this can be explained in part by their cryptic nature and difficulty in identifying genets. In addition the difficulty (relative to plants and animals) in developing molecular markers for fungal population genetics contributes to the lack of research in this area. This study examines the ability of restriction-site associated DNA (RAD) sequencing to generate SNPs in Laccaria bicolor. Eighteen samples of morphologically identified L. bicolor from the United States and Europe were selected for this project. The RAD sequencing method produced anywhere from 290 000 to more than 3 000 000 reads. Mapping these reads to the genome of L. bicolor resulted in 84 000-940 000 unique reads from individual samples. Results indicate that incorporation of non-L. bicolor taxa into the analysis resulted in a precipitous drop in shared loci among samples, suggests the potential of these methods to identify cryptic species. F-statistics were easily calculated, although an observable "noise" was detected when using the "All Loci" treatment versus filtering loci to those present in at least 50% of the individuals. The data were analyzed with tests of Hardy-Weinburg equilibrium...

Molecular genetic analysis of Giardia intestinalis isolates at the glutamate dehydrogenase locus

Monis, P.; Mayrhofer, G.; Andrews, R.; Homan, W.; Limper, L.; Ey, P.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Publicado em //1996 EN
Relevância na Pesquisa
55.79%
Samples of DNA from a panel of Giardia isolated from humans and animals in Europe and shown previously to consist of 2 major genotypes–‘Polish’ and ‘Belgian’–have been compared with human-derived Australian isolates chosen to represent distinct genotypes (genetic groups I–IV) defined previously by allozymic analysis. Homologous 0·52 kilobase (kb) segments of 2 trophozoite surface protein genes (tsa417 and tsp11, both present in isolates belonging to genetic groups I and II) and a 1·2 kb segment of the glutamate dehydrogenase (gdh) gene were amplified by the polymerase chain reaction (PCR) and examined for restriction fragment length polymorphisms (RFLPs). Of 21 ‘Polish’ isolates that were tested, all yielded tsa417-like and tsp11-like PCR products that are characteristic of genetic groups I or II (15 and 6 isolates respectively) in a distinct assemblage of G. intestinalis from Australia (Assemblage A). Conversely, most of the 19 ‘Belgian’ isolates resembled a second assemblage of genotypes defined in Australia (Assemblage B) which contains genetic groups III and IV. RFLP analysis of gdh amplification products showed also that ‘Polish’ isolates-were equivalent to Australian Assemblage A isolates (this analysis does not distinguish between genetic groups I and II) and that ‘Belgian’ isolates were equivalent to Australian Assemblage B isolates. Comparison of nucleotide sequences determined for a 690 base-pair portion of the gdh PCR products revealed ≥ 99·0% identity between group I and group II (Assemblage A/‘Polish’) genotypes...

The genetic improvement of wheat and barley for reproductive frost tolerance.

Reinheimer, Jason
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
55.71%
The aim of the research reported in this thesis was to identify genetic variation for Reproductive Frost Tolerance (RFT) in barley, characterise the genetic basis of the observed tolerance and devise and execute a strategy to incorporate the tolerance into germplasm adapted to Australian production environments. Effects of wheat chromosome regions syntenous to the barley RFT loci were also investigated. A field based screening nursery was developed to characterise barley germplasm for RFT. A diverse collection of international barley germplasm was screened for RFT to identify barley genotypes exhibiting better levels of RFT than what was available in Australian cultivated germplasm. Three lines were identified as having an increased level of RFT and populations derived from these three lines were used to QTL map RFT traits. One QTL was common between the three populations and a second QTL was common between 2 of the populations. These two loci were found to control a reduction in Frost Induced Sterility (FIS) and frost induced grain damage. One of the barley QTL spanned the vernalisation response gene and vegetative frost tolerance locus vrn-H1/Fr-H1. The syntenous genomic regions in hexaploid wheat were investigated to determine if they had an effect on RFT. Two sets of wheat germplasm containing variation for winter/spring alleles of vrn-A1...

Genetic analysis of tolerance to Boron toxicity in the legume Medicago truncatula

Bogacki, P.; Peck, D.; Nair, R.; Howie, J.; Oldach, K.
Fonte: BioMed Central Ltd. Publicador: BioMed Central Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
65.72%
Background: Medicago truncatula Gaertn. (barrel medic) is cultivated as a pasture legume for its high protein content and ability to improve soils through nitrogen fixation. Toxic concentrations of the micronutrient Boron (B) in agricultural soils hamper the production of cereal and leguminous crops. In cereals, the genetic analysis of B tolerance has led to the development of molecular selection tools to introgress and maintain the B tolerance trait in breeding lines. There is a comparable need for selection tools in legumes that grow on these toxic soils, often in rotation with cereals. Results: Genetic variation for B tolerance in Medicago truncatula was utilised to generate two F2 populations from crosses between tolerant and intolerant parents. Phenotyping under B stress revealed a close correlation between B tolerance and biomass production and a segregation ratio explained by a single dominant locus. M. truncatula homologues of the Arabidopsis major intrinsic protein (MIP) gene AtNIP5;1 and the efflux-type transporter gene AtBOR1, both known for B transport, were identified and nearby molecular markers screened across F2 lines to verify linkage with the B-tolerant phenotype. Most (95%) of the phenotypic variation could be explained by the SSR markers h2_6e22a and h2_21b19a...

Genetic analysis of tolerance to the root lesion nematode Pratylenchus neglectus in the legume Medicago littoralis

Oldach, K.H.; Peck, D.M.; Nair, R.M.; Sokolova, M.; Harris, J.; Bogacki, P.; Ballard, R.
Fonte: Biomed Central Publicador: Biomed Central
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
55.73%
BACKGROUND: The nematode Pratylenchus neglectus has a wide host range and is able to feed on the root systems of cereals, oilseeds, grain and pasture legumes. Under the Mediterranean low rainfall environments of Australia, annual Medicago pasture legumes are used in rotation with cereals to fix atmospheric nitrogen and improve soil parameters. Considerable efforts are being made in breeding programs to improve resistance and tolerance to Pratylenchus neglectus in the major crops wheat and barley, which makes it vital to develop appropriate selection tools in medics. RESULTS: A strong source of tolerance to root damage by the root lesion nematode (RLN) Pratylenchus neglectus had previously been identified in line RH-1 (strand medic, M. littoralis). Using RH-1, we have developed a single seed descent (SSD) population of 138 lines by crossing it to the intolerant cultivar Herald. After inoculation, RLN-associated root damage clearly segregated in the population. Genetic analysis was performed by constructing a genetic map using simple sequence repeat (SSR) and gene-based SNP markers. A highly significant quantitative trait locus (QTL), QPnTolMl.1, was identified explaining 49% of the phenotypic variation in the SSD population. All SSRs and gene-based markers in the QTL region were derived from chromosome 1 of the sequenced genome of the closely related species M. truncatula. Gene-based markers were validated in advanced breeding lines derived from the RH-1 parent and also a second RLN tolerance source...

Genetic architecture of idiopathic generalized epilepsy: Clinical genetic analysis of 55 multiplex families

Marini, C.; Scheffer, I.; Crossland, K.; Grinton, B.; Phillips, F.; McMahon, J.; Turner, S.; Dean, J.; Kivity, S.; Mazarib, A.; Neufeld, M.; Korczyn, A.; Harkin, L.; Dibbens, L.; Wallace, R.; Mulley, J.; Berkovic, S.
Fonte: Blackwell Publishing Inc Publicador: Blackwell Publishing Inc
Tipo: Artigo de Revista Científica
Publicado em //2004 EN
Relevância na Pesquisa
55.75%
Summary: Purpose: In families with idiopathic generalized epilepsy (IGE), multiple IGE subsyndromes may occur. We performed a genetic study of IGE families to clarify the genetic relation of the IGE subsyndromes and to improve understanding of the mode(s) of inheritance. Methods: Clinical and genealogic data were obtained on probands with IGE and family members with a history of seizures. Families were grouped according to the probands' IGE subsyndrome: childhood absence epilepsy (CAE), juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and IGE with tonic–clonic seizures only (IGE-TCS). The subsyndromes in the relatives were analyzed. Mutations in genes encoding α1 and γ2 γ-aminobutyric acid (GABA)-receptor subunits, α1 and β1 sodium channel subunits, and the chloride channel CLC-2 were sought. Results: Fifty-five families were studied. 122 (13%) of 937 first- and second-degree relatives had seizures. Phenotypic concordance within families of CAE and JME probands was 28 and 27%, respectively. JAE and IGE-TCS families had a much lower concordance (10 and 13%), and in the JAE group, 31% of relatives had CAE. JME was rare among affected relatives of CAE and JAE probands and vice versa. Mothers were more frequently affected than fathers. No GABA-receptor or sodium or chloride channel gene mutations were identified. Conclusions: The clinical genetic analysis of this set of families suggests that CAE and JAE share a close genetic relation...

Genetic insights into population recovery following experimental perturbation in a fragmented landscape

Peakall, Rodney; Lindenmayer, David
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.7%
We investigated the mechanism of population recovery in the Australian bush rat, Rattus fuscipes, following experimental perturbation in a fragmented landscape. Our study involved genetic monitoring over 24 months following the removal of animals from seven sites by intense trapping. A total of 171 bush rats was removed and statistical analysis confirmed a significant knockdown. At one site, local extinction followed the perturbation, while population sizes at 24 months varied from 37% to 90% of the original population size at the remaining sites. The outcomes of genetic analysis at 11 microsatellite loci and mtDNA indicated that population recovery was achieved predominantly by residual animals: recovery populations were genetically more similar to their respective pre-treatment population than near neighbours; assignment tests detected few immigrants; there was no influx of new immigrant alleles and haplotypes. This finding is consistent with emerging evidence for restricted gene flow in bush rats. The local extinction observed at one site indicate that, under severe perturbation restricted dispersal limits opportunities for, and the rate of, population recovery. Thus, while the bush rat appears resilient to substantial population size perturbation...

GENALEX 6: genetic analysis in Excel. Population genetic software for teaching and research

Peakall, Rodney; Smouse, Peter E
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.69%
GENALEX is a user-friendly cross-platform package that runs within Microsoft Excel, enabling population genetic analyses of codominant, haploid and binary data. Allele frequency-based analyses include heterozygosity, F statistics, Nei's genetic distance,