Meiotic Configurations
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. True polyploid meiosis in the human male
Abstract Polyploidy does not usually occur in germinal cells of mammals and other higher vertebrates. We describe a unique example of mosaic autotetraploidy in the meiosis of a human male. Although the original observations were made in the late 1960s, we did not publish them at that time, because we expected to detect further examples that could be describe
Genet. Mol. Biol.. Publicado em: 21/05/2018
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2. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): hybrids and their genitors
Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic
Acta Scientiarum Agronomy. Publicado em: 2011
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3. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): hybrids and their genitors.
Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic
Acta Scientiarum. Agronomy. Publicado em: 2011
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4. Cytogenetic data for Paspalum notatum Flügge accessions / Dados citogenéticos para acessos de Paspalum notatum Flügge
Muitas espécies do genus Paspalum L. são importantes forragens, devido à qualidade, produtividade e tolerância para o stress ambiental. Números cromossômicos, configurações meióticas e fertilidade do pólen foram analisados em uma coleção de 85 acessos de Paspalum notatum Flügge e sete acessos de Pensacola (P. notatum var saurae). Todos os acesso
Publicado em: 2010
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5. A second case of multivalent meiotic configurations in diploid species of Anura
Nós analisamos os cromossomos meióticos de espécimes dos dois grupos cariotípicos de Physalaemus petersi (Jiménez de la Espada, 1872) descritos na literatura. Configurações multivalentes (anéis e cadeias) foram descritas em ambos os grupos. Essa organização meiótica resultou da associação terminal de cromossomos não-homólogos e a análise de p
Genetics and Molecular Biology. Publicado em: 2000-03
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6. Estudo citogenetico comparativo de Edalorhina perezi e Physalaemus petersi (Amphibia, Anura, Leptodactylidae)
Sixty one specimens of Physalaemus petersi and seven of Edalorhina perezi (Leptodactylidae, Anura) from Acre State, Brazil, were studied, to contribute to phylogenetic relationship studies between these two neotropical genera. Chromosome preparations were obtained from cellular suspensions of testis and intestinal epithelium. These cytological preparations w
Publicado em: 1996
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7. A maximum likelihood algorithm for genome mapping of cytogenetic loci from meiotic configuration data.
Frequencies of meiotic configurations in cytogenetic stocks are dependent on chiasma frequencies in segments defined by centromeres, breakpoints, and telomeres. The expectation maximization algorithm is proposed as a general method to perform maximum likelihood estimations of the chiasma frequencies in the intervals between such locations. The estimates can
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8. Meiosis in two human reciprocal translocations.
Analysis of meiotic chromosomes from two human male translocation heterozygotes is reported. One had total sterility after maturation arrest and chain configurations at meiosis, and the second had a abnormal children who were presumed to be genetically unbalanced.
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9. The strong ADH1 promoter stimulates mitotic and meiotic recombination at the ADE6 gene of Schizosaccharomyces pombe.
The effect of the strong promoter from the alcohol dehydrogenase gene on mitotic and meiotic intragenic recombination has been studied at the ade6 locus of the fission yeast Schizosaccharomyces pombe. A 700-bp fragment containing the functional adh1 promoter was used to replace the weak wild-type promoter of the ade6 gene. Analysis of mRNA showed that strain
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10. "Alternate-2" Disjunction Does Not Exist
John and Lewis (1965) proposed a model of disjunction of translocation heterozygotes that defined two types of alternate disjunction, alternate-1 and alternate-2, differing from the classic view of only one type. Endrizzi (1974), and subsequent workers citing him, claim to have observed two distinct alternate disjunction configurations, corresponding to John
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11. Nature and Consequences of Induced Chromosome Damage in Mammals
There are marked qualitative and quantitative differences in the patterns of chromosomal damage observed after irradiation of spermatogonia, spermatozoa and oocytes of mice. These differences often result from reduced or zero transmission of particular classes of abberration arising in pre-meiotic germ cells. Probably this is the reason why the level of X-ch
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12. Patterns of Meiotic Recombination in Human Fetal Oocytes
Abnormal patterns of meiotic recombination (i.e., crossing-over) are believed to increase the risk of chromosome nondisjunction in human oocytes. To date, information on recombination has been obtained using indirect, genetic methods. Here we use an immunocytological approach, based on detection of foci of a DNA mismatch-repair protein, MLH1, on synaptonemal
The American Society of Human Genetics.