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Registros recuperados: 40 | |
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Lima,J. Fernando de S.; Kasahara,Sanae. |
The genus Calomys Waterhouse, 1837 is widely distributed within South America, being found in Venezuela, Colombia, Peru, Bolivia, Brazil, Paraguay, Uruguay and Argentina. Specimens of Calomys were collected in Formoso do Araguaia, Tocantins, Brazil. For chromosome characterization standard staining techniques and as G-banding and nucleolar organizer region were used. The karyotype was 2n=46 and AN=66. The X chromosome is a medium metacentric and the Y chromosome a small acrocentric chromosome. Chromosome homologies with other species were observed. Probably, karyotype differences were basically due to Robertsonian rearrangements. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calomys; Karyotype; Chromosome; Tocantins; Brazil. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212001000200019 |
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Mccombie, Helen; Lapegue, Sylvie; Cornette, Florence; Ledu, Christophe; Boudry, Pierre. |
Alterations of chromosome number have been observed in the somatic tissue of Crassostrea gigas diploids and artificial polyploids bred in this species. Tetraploid animals with lower chromosome counts in some or all of their somatic tissue are considered undesirable as parents either for commercial triploids (produced via a cross with diploids) or for tetraploid breeding because (1) they may confer the tendency to lose chromosomes and revert to lower ploidy levels to their offspring or (2) their offspring could have a lower ploidy directly because of potential links between somatic and gametic chromosome loss. The present study evaluated the phenomenon in bi-parental tetraploid families bred from parents of differing ploidy quality, including a... |
Tipo: Text |
Palavras-chave: Tetraploid; Chromosome; Genetic; Crassostrea gigas; Oyster. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3435.pdf |
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Bhaumik,Pranami; Ghosh,Priyanka; Ghosh,Sujay; Feingold,Eleanor; Ozbek,Umut; Sarkar,Biswanath; Dey,Subrata Kumar. |
Abstract Alzheimer's disease and Down syndrome often exhibit close association and predictively share common genetic risk-factors. Presenilin-1 (PSEN-1) and Apolipoprotein E (APOE) genes are associated with early and late onset of Alzheimer's disease, respectively. Presenilin −1 is involved in faithful chromosomal segregation. A higher frequency of the APOE ε4 allele has been reported among young mothers giving birth to Down syndrome children. In this study, 170 Down syndrome patients, grouped according to maternal meiotic stage of nondisjunction and maternal age at conception, and their parents were genotyped for PSEN-1 intron-8 and APOE polymorphisms. The control group consisted of 186 mothers of karyotypically normal children. The frequencies of the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome; Genetic polymorphism; Karyotype; Meiosis; Microsatellite markers. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572017000400577 |
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Leitao, Alexandra; Boudry, Pierre; Labat, Jean-philippe; Thiriot-quievreux, Catherine. |
Chromosomes of six cupped oyster species were studied using karyometric analysis alter conventional Giemsa staining, and silver staining, Karyotypes of Crassotrea angulata (nine metacentric and one submetacentric chromosome pairs), C. sikamea (nine metacentric and one submetacentric chromosome pairs), C. virginica (eight metacentric and two submetacentric chromosome pairs), C, ariakensis (eight metacentric and two submetacentric chromosome pairs), C, gasar (six metacentric and four submetacentric chromosome pairs), and Saccostrea commercialis (eight metacentric and two submetacentric chromosome pairs) are distinguishable by the number and position of the submetacentric chromosome pair and by the location of nucleolus organizer regions, Comparative... |
Tipo: Text |
Palavras-chave: Bivalvia; Cytotaxonomy; Karyotype; Chromosome; Cupped oyster. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-2737.pdf |
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Pozzobon,Marisa Toniolo; Machado,Ana Caroline de Carvalho; Vaio,Magdalena; Valls,José Francisco Montenegro; Peñaloza,Andréa del Pilar de Souza; Santos,Sileuza dos; Côrtes,Ana Luiza; Rua,Gabriel Hugo. |
Chromosome numbers were counted in 126 new accessions of 50 Paspalum species from Brazil, Argentina, Paraguay and Bolivia. The chromosome numbers 2n=12, 20, 24, 30, 40, 50, 60, 80 were confirmed. Chromosome numbers for P. arenarium (2n=20), P. barretoi (2n=20), P. aff. ceresia (2n=40), P. corcovadense (2n=20), P. crispulum (2n=20), P. flaccidum (2n=40), P. nummularium (2n=20), P. scalare (2n=20), P. vescum (2n=20) and P. rectum (2n=20) and a diploid cytotype of P. malacophyllum are reported for the first time. The predominance of tetraploid accessions (43.6%) was confirmed, but an unusually high number of diploid species (44%) and accessions (35.7%) was found. These results open new perspectives for breeding programs, phylogenetic studies, and for research... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome; Diploid; Polyploid; Ploidy level; Hybrid; Genetic resources. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782008000500014 |
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Carvalho, Thaís Lima; UNESP - IBB; Curi, Rogério Abdallah; UNESP - FMVZ; Santiloni, Valquíria; UNESP - IBB; Chieregatto, Cleyde Angélica Ferreira da Silva; Sociedade dos Zoológicos do Brasil; Rocha, Guaracy Tadeu; UNESP - IBB; Mota, Lígia Souza Lima Silveira da; UNESP - IBB. |
The bush dog (Speothos venaticus) is a South American canid, included in the IBAMA (Brazilian Institute of Environment and Renewable Natural Resources) official list of animals threatened with extinction, in the vulnerable category. As a preservation and conservation strategy, specimens kept in captivity by Brazilian Institutions are monitored by a management plan. In order to characterize and analyze the genetic variability of bush dog specimens, a cytogenetic analysis was carried out, and microsatellite data were also obtained through the use of 15 primers, originally developed for the domestic dog (Canis familiaris). All tested primers showed transferability and amplified fragment sizes similar to those described for the canine genome. From the total... |
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Palavras-chave: 2.02.04.00-0 bush dog; Canids; Chromosome; Microsatellite; Mosaicism Genética Animal bush dog; Canids; Chromosome; Microsatellite; Mosaicism. |
Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/6775 |
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Fonteles,Soraia B.A.; Lopes,Carlos E.; Akama,Alberto; Fernandes,Flora M.C.; Porto-Foresti,Fábio; Senhorini,José A.; Daniel-Silva,Maria de Fátima Z.; Foresti,Fausto; Almeida-Toledo,Lurdes Foresti de. |
A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs) were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome; Fish; Gymnotidae; Electric eel. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200010 |
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Barbosa,Sandro; Davide,Lisete Chamma; Pereira,Antônio Vander. |
Cytogenetic studies were carried out on five accesses of interspecific hybrids of Pennisetum purpureum and Pennisetum glaucum and their parentals, which are part of the Forage Germplasm Bank of the "Centro Nacional de Pesquisa de Gado de Leite" of EMBRAPA, Brazil. The mitotic cytogenetic analysis, performed using stain by Schiff reactive, confirmed the chromosome number of 2n = 14, 28 and 21 for the accesses of P. glaucum, P. purpureum and their hybrids, respectively. For each access, descriptions of the chromosome complement and idiograms are presented which allowed to establish the karyotypic relationships between the hybrids and their parentals. Based on the total chromosomal length data it was possible to establish the karyotype classification of the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Elephant grass; Pearl millet; Interspecific hybrids; Cytogenetic; Ideograms; Chromosome. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542003000100003 |
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Ferreira,Amilton; Mesa,Alejo. |
The thirteen species of Phaneropterinae here studied can be arranged in four different groups according to their basic karyological traits. All of them share the same kind of chromosomal sex determining mechanism with X0(male) and XX(female). The X chromosome differs among species and always appears heteropycnotic during prophase I, it is the largest in the set and segregates precociously during anaphase I. Among the species, the karyotypes varies in fundamental number between 31 to 21. The meaning of these significant changes in the karyotypes in relation to the phylogeny within some large taxonomic group of species is discussed. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Chromosome; Evolution. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2007000400003 |
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Registros recuperados: 40 | |
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