| Registro completo |
| Provedor de dados: |
Genet. Mol. Biol.
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| País: |
Brazil
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| Título: |
C-banding and fluorescent in situ hybridization with rDNA sequences in chromosomes of Cycloneda sanguinea Linnaeus (Coleoptera, Coccinellidae)
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| Autores: |
Maffei,Eliane Mariza Dortas
Pompolo,Silvia das Graças
Petitpierre,Eduard
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| Data: |
2004-01-01
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| Ano: |
2004
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| Palavras-chave: |
In situ hybridization
RDNA sequences
Sequential FISH/Ag-NOR staining
C-banding
Cycloneda sanguinea
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| Resumo: |
The aim of this study was to describe mitotic and meiotic chromosomes of Cycloneda sanguinea using C-banding, fluorescent in situ hybridization (FISH) rDNA probes, and sequential FISH/Ag-NOR staining. The chromosome number was 2n = 18 + XX for females and 2n = 18 + Xy for males. The X chromosome was metacentric and the Y chromosome was very small. During meiosis, the karyotypic meioformula was n = 9 + Xy p, and sex chromosomes configured a parachute at metaphase I. At the beginning of pachytene, bivalents were still individualized, and sex chromosomes were associated end-to-end through the heteropycnotic region of the X chromosome. Later in pachytene, further condensation led to the formation of a pseudo-ring by the sex bivalent. All chromosomes showed pericentromeric heterochromatin. FISH and sequential FISH/Ag-NOR staining evidenced the location of the nucleolar organizer region in one pair of autosomes (at spermatogonial metaphase). During meiosis, these genes were mapped to a region outside the sex vesicle by FISH, although Xy p was deeply stained with silver at metaphase I. These results suggest that these argyrophilic substances are of a nucleolar protein nature, and seem to be synthesized by a pair of autosomes and imported during meiosis (prophase I) to the sex pair, during the association of the sex chromosomes.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000200011
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| Editor: |
Sociedade Brasileira de Genética
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| Relação: |
10.1590/S1415-47572004000200011
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| Formato: |
text/html
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| Fonte: |
Genetics and Molecular Biology v.27 n.2 2004
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| Direitos: |
info:eu-repo/semantics/openAccess
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