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Cytogenetic analyses of two Curimatidae species (Pisces; Characiformes) from the Paranapanema and Tietê Rivers.
De Rosa, L V S; Foresti, F; Martins, C; Oliveira, C; Sobrinho, P E; Wasko, A P.
Afiliação
  • De Rosa LV; Departamento de Morfologia, Instituto de Biociencias, Universidade Estadual Paulista, 18618-000, Botucatu, SP, Brazil.
Braz J Biol ; 67(2): 333-8, 2007 May.
Article em En | MEDLINE | ID: mdl-17876445
Cytogenetic analyses were performed in two Curimatidae species (Steindachnerina insculpta and Cyphocharax modesta) from the Paranapanema and Tietê Rivers (São Paulo State, Brazil), showing a karyotype composed of 54 meta-submetacentric chromosomes in both species. Silver- and chromomycyn-staining and fluorescent in situ hybridization (FISH) using a 18S rDNA probe indicated that the nucleolar organizer regions (NORs) of both species are localized in the terminal region of the long arm of two metacentric chromosomes. Although a single NOR system was evidenced in both analyzed species, S. insculpta and C. modesta presented the nucleolar organizer regions in distinct chromosome pairs, indicating that these cistrons can be considered cytogenetic markers. Variation on the amount and distribution of the constitutive heterochromatin (C-bands) could also be detected between the two species - while S. insculpta presented few heterochromatic blocks, intensely stained C-bands were evidenced in C. modesta specially in the terminal region of the long arm of the NOR-bearing chromosomes. Although most Curimatidae species have been characterized by homogeneous karyotypes, isolated populations could be established under different environmental conditions leading to karyotype micro-structure variations specially related to the NORs localization and C-banding distribution. The obtained data were useful for the cytogenetic characterization and differentiation of S. insculpta and C. modesta and could be used in evolutionary inferences in the Curimatidae group.
Assuntos
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Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: RNA Ribossômico 18S / Bandeamento Cromossômico / Peixes / Região Organizadora do Nucléolo Limite: Animals País/Região como assunto: America do sul / Brasil Idioma: En Revista: Braz J Biol Assunto da revista: BIOLOGIA Ano de publicação: 2007 Tipo de documento: Article País de afiliação: Brasil País de publicação: Brasil
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Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: RNA Ribossômico 18S / Bandeamento Cromossômico / Peixes / Região Organizadora do Nucléolo Limite: Animals País/Região como assunto: America do sul / Brasil Idioma: En Revista: Braz J Biol Assunto da revista: BIOLOGIA Ano de publicação: 2007 Tipo de documento: Article País de afiliação: Brasil País de publicação: Brasil