|
|
|
| Registros recuperados: 107 | |
|
|
| GALLO, P. H; MICHELETTI, P. L.; BOLDRINI, K. R.; RISSO-PASCOLOTTO, C.; PAGLIARINI, M. S.; VALLE, C. B. do. |
| Microsporogenesis of several Brachiaria species of the Brazilian collection at Embrapa Beef Cattle has been analyzed in detail. This paper reports abnormal cytokinesis in three accessions of three different species (Brachiaria humidicola, 2n = 4x = 36, Brachiaria decumbens, 2n = 4x = 36, and Brachiaria dura, 2n = 6x = 54). Chromosomes paired in bi-, tri-, and quadrivalents in these accessions, whereas chromosome segregation at meiosis I was characterized by exclusion of laggards as micronuclei. In a high number of meiocytes, the first sign of cytokinesis appeared only in metaphase II and did not divide the meiocyte into a dyad. Total absence of cytokinesis was also detected among meiocytes in the second division. Since in both cases the two metaphase... |
| Tipo: Artigo de periódico |
Palavras-chave: Braquiária; Brachiaria dura; Campo Grande; Mato Grosso do Sul; Brasil; Feed crops; Feed grasses.; Brachiaria Humidicola; Brachiaria Decumbens; Citogenética Vegetal; Gramínea Forrageira; Melhoramento Genético Vegetal; Poliploidia.; Planta Forrageira; Cytogenetics; Brazil; Plant breeding; Polyploidy.. |
| Ano: 2007 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/326409 |
| |
|
|
| Pamponet,Vanessa de Carvalho Cayres; Carneiro,Paulo Luiz Souza; Affonso,Paulo Roberto Antunes de Mello; Miranda,Viviam Souto; Silva Júnior,Juvenal Cordeiro; Oliveira,Claudine Gonçalves de; Gaiotto,Fernanda Amato. |
| Few reports are available about the ichthyofauna of typical semi-arid rivers, although the regional diversity has been constantly threatened by human activities, mainly related to impoundment and construction of dams. The goal of the present work was to evaluate using different methods, the population genetic structure of a characin fish, Astyanax aff. bimaculatus, widespread throughout hydrographic basins of Bahia, Northeastern Brazil. Morphological (meristic and morphometric data), cytogenetic (karyotype and Ag-NOR), and molecular (RAPD and SPAR) analyses were carried out in specimens collected upstream and downstream of Pedra Dam, in the main channel of Contas River (Contas River Basin), and in the Mineiro stream, which belongs to the adjacent Recôncavo... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Morphometry; Cytogenetics; RAPD; Population structure; Contas River. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400010 |
| |
|
| |
|
|
| Moreira,Camila Nascimento; Di-Nizo,Camilla Bruno; Silva,Maria José de Jesus; Yonenaga-Yassuda,Yatiyo; Ventura,Karen. |
| Pseudoryzomys simplex, the false rice rat, is a monotypic genus of the Oryzomyini tribe (Sigmodontinae) distributed in part of Bolivia, Paraguay, Argentina and Brazil. Its diploid number has been described as 56 acrocentric chromosomes decreasing in size and no karyotype figure has been depicted. Herein, we present karyotypic data on P. simplex, including chromosome banding and molecular fluorescent in situ hybridization using telomeric sequences and the whole X-chromosome of its sister clade Holochilus brasiliensis (HBR) as probes. A case of remarkable autosomal heteromorphism due to the presence of a whole heterochromatic arm leading to the variability of FN is reported, as well as the occurrence of regions of homology between the X and Y chromosomes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; Fluorescent in situ hybridization; Heterochromatin; Oryzomyini. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000200010 |
| |
|
| |
|
|
| Ferreira,Kátia; Torres,Giovana Augusta; Carvalho,Isabelle Vilela de; Davide,Lisete Chamma. |
| The objective of this work was to compare the meiotic behavior and pollen grain viability of three species of Crotalaria. Slides for meiotic analysis were prepared by the air-drying technique. Pollen grain viability was measured by three staining procedures (Alexander's solution, tetrazolium chloride and fluorescein diacetate) and in vitro germination in a sucrose solution. Eight bivalents were observed, confirming previous reports on populations from other regions of Brazil, as well as from other countries. All species showed abnormal meiotic behavior as follows: in Crotalaria micans, cytomixis and abnormal chromosome pairing in diakinesis; in C. spectabilis, abnormal chromosome pairing in diplotene; in C. zanzibarica, shrunk nuclei in leptotene and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crotalaria; Cytogenetics; Cytomixis; Meiosis; Pollen grain viability. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001200012 |
| |
|
| |
|
|
| Svartman,Marta. |
| Marsupials, one of the three main groups of mammals, are only found in Australia and in the American continent. Studies performed in Australian marsupials have demonstrated the great potential provided by the group for the understanding of basic genetic mechanisms and chromosome evolution in mammals. Genetic studies in American marsupials are relatively scarce and cytogenetic data of most species are restricted to karyotype descriptions, usually without banding patterns. Nevertheless, the first marsupial genome sequenced was that of Monodelphis domestica, a South American species. The knowledge about mammalian genome evolution and function that resulted from studies on M. domestica is in sharp contrast with the lack of genetic data on most American... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Marsupials; Cytogenetics; Chromosome evolution. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400002 |
| |
|
| |
|
| |
|
| |
|
| |
|
|
| MENDES-BONATO, A. B.; VALLE, C. B. do; PAGLIARINI, M. S.; PENTEADO, M. I. de O.. |
| No gênero Brachiaria, muitas espécies e acesso são poliplóides e apomíticos, o que dificulta o melhoramento via hibridização. Uma ampla caracterização citogenética, incluindo determinação do número de cromossomos e avaliação detalhada do comportamento meiótico, vem sendo realizada na coleção de germoplasma deste gênero a fim de auxiliar na seleção de genitores e explicar problemas na fecundidade dos acessos e híbridos do programa de melhoramento desenvolvido pela Embrapa Gado de Corte. Neste estudo, 22 acessos de Brachiaria brizantha foram analisados. Destes, um é diplóide (2n = 2x = 18), 18 são tetraplóides (2n = 6x = 54). Anormalidades meióticas variaram de 2,85% a 5,55% nas células em divisão no acesso diplóide e de 1,03% a 69,48% nos acessos... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Apomixia; Brachiaria Brizantha; Citogenética Vegetal; Cromossoma; Poliploidia.; Cytogenetics; Polyploidy.. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/325562 |
| |
|
|
| Carvalho,Rafael Augusto de; Sanchez,Sebástian; Swarça,Ana Claudia; Fenocchio,Alberto Sergio; Martins-Santos,Isabel C.; Dias,Ana Lúcia. |
| This study presents chromosomal data of Megalonema platanum from rio Tibagi, Paraná, Brazil and from rio Paraná, Argentina. The diploid number was equal 54 with karyotype composition of 24m+16sm+2st+12a in both populations. The AgNOR sites were detected in the terminal position of a submetacentric pair of the two analyzed populations, coinciding with secondary constrictions on the short arm of pair 15. CMA3 and FISH with 18S rDNA probe displayed fluorescent signals that correspond to the AgNOR sites and secondary constriction. The presence of a small acrocentric supernumerary chromosome can be observed in M. platanum from rio Tibagi, with centromeric heterochromatin. Others heterochromatic blocks were evidenced in the terminal position of some chromosome... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; C-banding; CMA3; FISH; NORs; Pimelodidae. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000100017 |
| |
|
|
| Kowalski,Samantha; Paiz,Leonardo Marcel; da Silva,Maelin; Machado,Amanda de Souza; Feldberg,Eliana; Traldi,Josiane Baccarin; Margarido,Vladimir Pavan; Lui,Roberto Laridondo. |
| ABSTRACT Historically, there are divergences in the species allocation between Centromochlus and Tatia. This study aimed to generate the first cytogenetic data about Centromochlus and, by analyzing a population of Centromochlus heckelii from the Amazon River basin, to contribute as evidence to a historical taxonomic dilemma. Diploid number of 46 chromosomes and a heteromorphic pair was found in the female karyotypes, thus characterizing a ZZ/ZW sex chromosome system. Pale blocks of heterochromatin were located in centromeric regions of some chromosomes; however, the exclusive female chromosome (W) is almost entirely heterochromatic. AgNORs were detected in terminal position on the short arms of one acrocentric pair in males and two chromosome pairs in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Centromochlinae; Cytogenetics; Sex chromosome system; Taxonomy; ZZ/ZW. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000300203 |
| |
|
|
| Barranco, P.; Cabrero, J.; Camacho, J.P.M.; Pascual, F.. |
| Morphological and cytogenetic analyses of a spontaneous gynandromorph of Pycnogaster inermis, found in a natural population in the Spanish Sierra Nevada, have shown that the left side was male and the right side female, with almost perfect bilateral symmetry. Ventral valves of the ovipositor were very short, appearing as two spurs; dorsal valves were longer but still shorter than normal. The specimen had an apparently normal testis on the left side and a well-developed ovary on the right side. Cytogenetic analysis revealed the presence of 2n = 28 + X0 chromosomes in the testis and 2n = 28 + XX in the ovary, the same as standard males and females, respectively, of this species. This suggests that the gynandromorphism occurred at a very early developmental... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Gynandromorphism; Cytogenetics; Pycnogaster inermis; Tettigoniidae; Orthoptera. |
| Ano: 1995 |
URL: http://www.repository.naturalis.nl/record/504051 |
| |
|
|
| Valentim,Francisco Carlos de Souza; Porto,Jorge Ivan Rebelo; Feldberg,Eliana. |
| Abstract Cytogenetic studies in the subfamily Potamotrygoninae have provided valuable insights into the understanding of the evolution and diversification of its species. In the present study, the chromosomal features of seven nominal potamotrygonin species are provided: Plesiotrygon iwamae (2n=74, FN=120), Potamotrygon amazona (2n=66, FN=107), P. constellata (2n=66, FN=110), P. leopoldi (2n=64, FN=102), P. motoro (2n=66, FN=106) from four different localities, and P. orbignyi (2n=66, FN=106), P. scobina (2n=66, FN=104), from Central Amazon. Additionally, we found a new karyomorph in P. wallacei. We considered the localization of Nucleolus Organizer Regions (NORs), as well as the pattern of constitutive heterochromatin, as species-specific characters. We... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Elasmobranchs; Cytogenetics; Chromosomal rearrangements; Sex chromosomes; Karyotypic diversity. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000400578 |
| |
|
| |
|
|
| Lessa,Gisele; Corrêa,Margaret M. O; Pessôa,Leila M; Zappes,Ighor A. |
| Kerodon rupestris (Wied, 1820) is the most specialized species among caviid rodents and is endemic to the extensive rocky outcrops in the semi-arid region in Brazil. Herein we describe different karyotypes for K. rupestris, based on samples collected in Itapajé, Ceará (CE), Iraquara in Bahia (BA), and Botumirim in Minas Gerais (MG). Our samples included northern, center and southern populations in the range of the species distribution. The results were compared with a karyotype from Pernambuco previously described for the species. The diploid number (2n = 52) was constant among the analyzed population samples, but the fundamental number (FN) varied from 92 in Itapajé (CE) and Iraquara (BA), to 94 in Botumirim (MG). Pericentric inversions affecting one... |
| Tipo: Info:eu-repo/semantics/report |
Palavras-chave: C-Bands; Cytogenetics; Kerodon rupestris; NOR. |
| Ano: 2013 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-93832013000200013 |
| |
|
| |
| Registros recuperados: 107 | |
|
|
|
