New occurrence of a macro B-chromosome in Astyanax scabripinnis paranae (Pisces, Characiformes, Characidae)
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 pos...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1994 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/64449 |
| Acceso en línea: | http://www.gmb.org.br/Revistas/V17/v17a25.pdf http://hdl.handle.net/11449/64449 |
| Access Level: | acceso abierto |
| Palabra clave: | animal cell chromosome analysis female fish karyotype male nonhuman supernumerary chromosome |
| Sumario: | 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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