New occurrence of a macro B-chromosome in Astyanax scabripinnis paranae (Pisces, Characiformes, Characidae)

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Data

1994-01-01

Autores

Maistro, E. L. [UNESP]
Foresti, F. [UNESP]
Oliveira, C. [UNESP]

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Resumo

Cytogenetic studies performed on 17 specimens (11 females and six males) of Astyanax scabripinnis paranae from the Cascatinha stream showed that this population has 2n = 50 chromosomes (8M + 22SM + 10ST + 10A), two chromosome pairs with NORs and conspicuous C-band positive blocks in the terminal position of the long arm of five chromosome pairs. Three females presented 2n = 51 chromosomes and the extra chromosome was a large metacentric similar in size and morphology to the first chromosome pair in the karyotype. This accessory chromosome was entirely heterochromatic in C-banded metaphases, which permitted its classification as a supernumerary chromosome. Some aspects related to the morphology of such macro B-chromosomes are discussed.

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Palavras-chave

animal cell, chromosome analysis, female, fish, karyotype, male, nonhuman, supernumerary chromosome

Como citar

Brazilian Journal of Genetics, v. 17, n. 2, p. 153-156, 1994.