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 | Acesso ao texto completo restrito à biblioteca da Embrapa Gado de Leite. Para informações adicionais entre em contato com rosangela.lacerda@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Gado de Leite. |
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Data corrente: |
22/04/2019 |
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Data da última atualização: |
24/01/2023 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
ROCHA, L. C.; FERREIRA, M. T. M.; CUNHA, I. M. F.; MITTELMANN, A.; TECHIO, V. H. |
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Afiliação: |
Laiane Corsini Rocha, UFLA; Marco Túlio Mendes Ferreira, UFLA; Isabela Martinez Fontes Cunha, UFLA; ANDREA MITTELMANN, CNPGL; Vânia Helena Techio, UFLA. |
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Título: |
45S rDNA sites in meiosis of Lolium multiflorum Lam.: variability, non-homologous associations and lack of fragility. |
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Ano de publicação: |
2019 |
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Fonte/Imprenta: |
Protoplasma, v. 256, n. 1, p. 227-235, 2019. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract In this study, we evaluated the behavior of 45S ribosomal DNA (rDNA) sites during the meiosis of Lolium multiflorum. The reason to study it in this species is that 45S rDNA sites are usually visualized as gaps in mitotic metaphase chromosomes and were initially denominated fragile sites (FSs). In different species, FSs were related to rearrangements that alter the karyotype and affect the chromosome pairing in meiosis. However, our findings show that the chromosome pairing in L. multiflorum is regular and, as in mitosis, the number of sites is variable. In diakinesis with five sites, one of the bivalents was in hemizygous state while, in diakinesis with seven sites, one of the bivalents had three conspicuous signals, two in syntheny in one of the homologous. Only four cells had gaps in the region of the 45S rDNA. Owing to the lower number of signals observed at the initial stages of meiosis, it is assumed that they are involved both in homologous and non-homologous associations and that they might assist the chromosome pairing. Regarding segregation, only meiocytes with five and six 45S rDNA signals were observed, and they were characterized by the segregation of 2/3 signals in the poles of anaphases I up to metaphases II; 2/2 and 3/3 in anaphases II and telophases II; and also 2/2 and 4/4 in the nuclei of tetrads, unlike the number of 45S signals expected. The numerical nonequivalence of sites among nuclei at later stages of meiosis is explained by the presence of chromosomes with hemizygous sites. MenosAbstract In this study, we evaluated the behavior of 45S ribosomal DNA (rDNA) sites during the meiosis of Lolium multiflorum. The reason to study it in this species is that 45S rDNA sites are usually visualized as gaps in mitotic metaphase chromosomes and were initially denominated fragile sites (FSs). In different species, FSs were related to rearrangements that alter the karyotype and affect the chromosome pairing in meiosis. However, our findings show that the chromosome pairing in L. multiflorum is regular and, as in mitosis, the number of sites is variable. In diakinesis with five sites, one of the bivalents was in hemizygous state while, in diakinesis with seven sites, one of the bivalents had three conspicuous signals, two in syntheny in one of the homologous. Only four cells had gaps in the region of the 45S rDNA. Owing to the lower number of signals observed at the initial stages of meiosis, it is assumed that they are involved both in homologous and non-homologous associations and that they might assist the chromosome pairing. Regarding segregation, only meiocytes with five and six 45S rDNA signals were observed, and they were characterized by the segregation of 2/3 signals in the poles of anaphases I up to metaphases II; 2/2 and 3/3 in anaphases II and telophases II; and also 2/2 and 4/4 in the nuclei of tetrads, unlike the number of 45S signals expected. The numerical nonequivalence of sites among nuclei at later stages of meiosis is explained by the presence of ... Mostrar Tudo |
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Palavras-Chave: |
Fragile sites; Hemizygosis; Syntheny of rDNA genes. |
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Thesaurus Nal: |
Chromosome segregation; Forage grasses. |
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Categoria do assunto: |
F Plantas e Produtos de Origem Vegetal |
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Marc: |
LEADER 02235naa a2200229 a 4500
001 2108361
005 2023-01-24
008 2019 bl uuuu u00u1 u #d
100 1 $aROCHA, L. C.
245 $a45S rDNA sites in meiosis of Lolium multiflorum Lam.$bvariability, non-homologous associations and lack of fragility.$h[electronic resource]
260 $c2019
520 $aAbstract In this study, we evaluated the behavior of 45S ribosomal DNA (rDNA) sites during the meiosis of Lolium multiflorum. The reason to study it in this species is that 45S rDNA sites are usually visualized as gaps in mitotic metaphase chromosomes and were initially denominated fragile sites (FSs). In different species, FSs were related to rearrangements that alter the karyotype and affect the chromosome pairing in meiosis. However, our findings show that the chromosome pairing in L. multiflorum is regular and, as in mitosis, the number of sites is variable. In diakinesis with five sites, one of the bivalents was in hemizygous state while, in diakinesis with seven sites, one of the bivalents had three conspicuous signals, two in syntheny in one of the homologous. Only four cells had gaps in the region of the 45S rDNA. Owing to the lower number of signals observed at the initial stages of meiosis, it is assumed that they are involved both in homologous and non-homologous associations and that they might assist the chromosome pairing. Regarding segregation, only meiocytes with five and six 45S rDNA signals were observed, and they were characterized by the segregation of 2/3 signals in the poles of anaphases I up to metaphases II; 2/2 and 3/3 in anaphases II and telophases II; and also 2/2 and 4/4 in the nuclei of tetrads, unlike the number of 45S signals expected. The numerical nonequivalence of sites among nuclei at later stages of meiosis is explained by the presence of chromosomes with hemizygous sites.
650 $aChromosome segregation
650 $aForage grasses
653 $aFragile sites
653 $aHemizygosis
653 $aSyntheny of rDNA genes
700 1 $aFERREIRA, M. T. M.
700 1 $aCUNHA, I. M. F.
700 1 $aMITTELMANN, A.
700 1 $aTECHIO, V. H.
773 $tProtoplasma$gv. 256, n. 1, p. 227-235, 2019.
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Registro original: |
Embrapa Gado de Leite (CNPGL) |
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| Registros recuperados : 8 | |
| 2. |  | CHAPAVAL, L.; BENEVIDES, S. D.; ALVES, F. S. F.; RAMOS, M. O.; VIANA, G. A. Produção integrada de caprinocultura leiteira. n: WORKSHOP INTEGRAÇÃO LAVOURA-PECUÁRIA-FLORESTA NA EMBRAPA, 2009, Brasília, DF. Resumos e palestras apresentados. Brasília, DF: Embrapa, 2009. 4 f. 1 CD-ROM.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Caprinos e Ovinos. |
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| 4. | | RAMOS, M. O.; MORORÓ, A. M.; NERES, L. DE S.; LOURENÇO JUNIOR, J. DE B.; CHAPAVAL, L. Avaliação da qualidade do leite de cabra produzido por agricultores dos estados do Rio Grande do Norte e do Ceará. In: CONGRESSO BRASILEIRO DE BUIATRIA, 10.; SEMANA DO MÉDICO VETERINÁRIO DO PARÁ, 37.; SIMPÓSIO PARAENSE DE MEDICINA VETERINÁRIA, 5., 2013, Belém. Anais... Belém: Associação Brasileira de Buiatria, 2013. 4 p.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sudeste. |
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| 5. | | RAMOS, M. O.; MORORÓ, A. M.; CHAPAVAL, L.; SOUZA, V. de; LOURENÇO FILHO, J. de B.; NEVES, L. de S. Caracterização higiênico-sanitária do leite caprino produzido por agricultores familiares do Ceará, Brasil. In: CONGRESSO INTERNACIONAL DO LEITE, 12.; WORSHOP DE POLÍTICAS PÚBLICAS, 12.; SIMPÓSIO DE SUSTENTABILIDADE DA ATIVIDADE LEITEIRA, 13., Porto Velho. Anais... Brasília, DF : Embrapa, 2013. 3 f. 1 CD-ROM.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Caprinos e Ovinos; Embrapa Pecuária Sudeste. |
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| 6. | | CHAPAVAL, L.; ALVES, F. S. F.; RAMOS, M. O.; CAMPOS, A. C. N; SOUZA, F. G. C. de; SOUSA, A. P. B. de; MORORÓ, A. M. Qualidade microbiológica de queijo de cabra produzido em dois Estados da Região Nordeste do Brasil. In: SIMPÓSIO INTERNACIONAL SOBRE CAPRINOS E OVINOS DE CORTE, 4.; FEIRA NACIONAL DO AGRONEGÓCIO DA CAPRINO-OVINOCULTURA DE CORTE, 3., 2009, João Pessoa. Anais... João Pessoa: EMEPA-PB, 2009. 4 f. 1 CD-ROM.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Caprinos e Ovinos. |
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| 7. | | RAMOS, M. O.; MORORÓ, A. M.; ARAÚJO, G. S.; BUDEL, J. C. de C.; LOURENÇO JÚNIOR, J. de B.; CHAPAVAL, L.; SOUZA, V. de. Caracterização dos sistemas de produção de leite caprino no Estado do Ceará, Brasil. In: CONGRESSO NORDESTINO DE PRODUÇÃO ANIMAL, 9., 2014, Ilhéus. Produção animal: novas diretrizes. Ilhéus: SNPA, 2014. 3 f.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Caprinos e Ovinos; Embrapa Pecuária Sudeste. |
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| 8. | | SOUZA, G. N. de; CHAPAVAL, L.; MORORÓ, A. M.; RAMOS, M. O.; SILVA, I. de A.; SANTOS, F. R. dos; MORAES, L. C. D. de; FARIA, C. G. de. Associação entre a contagem de células somáticas e contagem total de bactérias de meios mamários de cabras leiteiras. In: CONGRESSO BRASILEIRO DE MICROBIOLOGIA, 25., 2009, Porto de Galinhas, PE. Anais... [São Paulo]: Sociedade Brasileira de Microbiologia, 2009. 1 CD-ROM. ResumoID:102-1.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Caprinos e Ovinos. |
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| Registros recuperados : 8 | |
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