Cytogenetic divergence between two sympatric species of Characidium (Teleostei, Characiformes, Crenuchidae) from the Machado River, Minas Gerais, Brazil
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Data
2006-01-01
Autores
Silva, Alexandre Rodrigues da [UNESP]
Maistro, Edson Luis [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Genética
Resumo
Cytogenetic studies were performed on two sympatric species of Characidium, C. gomesi and C. cf. zebra, from the Grande River basin, Minas Gerais State, Brazil. Although both species had a chromosome number of 50 with a karyotype exclusively consisting of meta- and submetacentric chromosomes, interspecific diversity was detected concerning the size of the two first chromosome pairs of the karyotypes. Active nucleolus organizer regions (NORs) were located at the terminal position on the long arm of the 17th pair of C. gomesi and at subterminal position on the long arm of the 23rd pair of C. cf. zebra. For both species the fluorochrome CMA3 stained only the NOR-bearing pair of chromosomes. The heterochromatin pattern also showed some differentiation between these species restricted to the centromeric or pericentromeric region of C. cf. zebra and practically absent in C. gomesi. These data are discussed concerning chromosome diversification in this fish group.
Descrição
Palavras-chave
Characidium gomesi, Characidium cf. zebra, Crenuchidae, NOR-banding, C-banding
Como citar
Genetics and Molecular Biology. Sociedade Brasileira de Genética, v. 29, n. 3, p. 459-463, 2006.