Chromosome divergence and NOR polymorphism in Bryconamericus aff. iheringii (Teleostei, Characidae) in the hydrographic systems of the Paranapanema and Ivaí Rivers, Paraná, Brazil
Genet. mol. biol
;
31(1,suppl): 203-207, 2008. ilus, mapas
Artículo
en Inglés
| LILACS
| ID: lil-484586
ABSTRACT
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.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Peces
/
Región Organizadora del Nucléolo
Límite:
Animales
País/Región como asunto:
America del Sur
/
Brasil
Idioma:
Inglés
Revista:
Genet. mol. biol
Asunto de la revista:
Genética
Año:
2008
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Estadual de Maringá/BR
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