Karyotypic variability in Iheringichthys labrosus (Teleostei, Pimelodidae) from the Tibagi River basin (Paraná State, Brazil)
Cytogenetic analyses were carried out in a populational sample of Iheringichthys labrosus from the Guaraúna River (Upper Tibagi River; Paraná State, Brazil) in order to provide a karyotypic comparison with another previously studied population from the Lower Tibagi River, characterized by the presen...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2008 |
| País: | Brasil |
| Institución: | Instituto Nacional de Pesquisas da Amazônia (INPA) |
| Repositorio: | Repositório Institucional do INPA |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio:1/15008 |
| Acceso en línea: | https://repositorio.inpa.gov.br/handle/1/15008 |
| Access Level: | acceso abierto |
| Palabra clave: | Brasil Chromosome Analysis Chromosome Pairing Controlled Study Heterochromatin Karyotyping Metaphase Nonhuman River Basin Supernumerary Chromosome Teleost Iheringichthys Labrosus Pimelodidae Teleostei |
| Sumario: | Cytogenetic analyses were carried out in a populational sample of Iheringichthys labrosus from the Guaraúna River (Upper Tibagi River; Paraná State, Brazil) in order to provide a karyotypic comparison with another previously studied population from the Lower Tibagi River, characterized by the presence of 32m + 8sm + 6st + 10a (2n = 56, FN = 102) and occurrence of supernumerary chromosomes (80% of individuals). The 17 specimens of I. labrosus (6 females, 10 males and 1 of unknown sex) from the Upper Tibagi River showed 2n = 56 chromosomes, a karyotype formula of 14m + 32sm + 4st + 6a (FN = 106), without evidence of sex chromosome heteromorphism or supernumerary chromosomes. The heterochromatin was detected at telomeric and centromeric positions in several chromosomal pairs. The Ag-nucleolar organizer regions were heteromorphic and located at terminal position on short arms of the 16th chromosomal pair, suggesting a positive association with heterochromatic regions. The inter-populational karyotypic differentiation reported indicates distinct evolutionary pathways within I. labrosus in the Tibagi River basin. ©FUNPEC-RP. |
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