Data/hora: 16/06/2024 10:24:36

Provedor de dados: | 74
País: | Brazil
Título: | Chromosome divergence and NOR polymorphism in Bryconamericus aff. iheringii (Teleostei, Characidae) in the hydrographic systems of the Paranapanema and Ivaí Rivers, Paraná, Brazil
Autores: | Capistano,Thiago Gomes; Castro,Ana Luiza de Brito Portela; Julio-Junior,Horácio Ferreira.
Data: | 2008-01-01
Ano: | 2008
Palavras-chave: | Bryconamericus; Characid fish; Chromosome divergence; Fluorescent in situ hybridization; NOR polymorphism.
Resumo: | Cytogenetic studies were carried out in three populations of Bryconamericus aff. iheringii from two hydrographic systems of the Paranapanema and Ivaí Rivers, separated by a watershed, both belonging to the upper Paraná River basin. Specimens had a constant diploid number 2n = 52 chromosomes. However, three karyotype formulae were identified in the three populations: B. aff. iheringii from the Maringá stream had 12M+18SM+8ST+14A (FN = 90); specimens from Keller River showed 8M+28SM+6ST+10A (FN = 94) and specimens from the Tatupeba stream had 8M+20SM+8ST+16A (FN = 88). Nucleolar organizer regions (NORs) were identified by silver nitrate staining and fluorescent in situ hybridization (FISH) with an 18S rDNA probe. Specimens from Tatupeba stream had a simple NOR system located in a terminal position of the short arm of a pair of large submetacentric chromosomes. Ag-NOR and FISH methodologies revealed multiple NORs in specimens of the Maringá stream and Keller River. Differences in chromosome structure and in NOR patterns in the three populations of B. aff. iheringii revealed fixed evolutionary chromosome divergence. Aspects related to karyotypic variations and to geographic isolation of these populations are discussed.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200006
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572008000200006
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.31 n.1 suppl.0 2008
Fonte: | info:eu-repo/semantics/openAccess