A ZZ/ZW sex chromosome system in Imparfinis mirini (Pisces, Siluriformes)
The cytogenetic analysis of 21 specimens of Imparfinis mirini showed the presence of 2n = 58 chromosomes in animals of both sexes. The basic karyotype consists of 22 metacentric and 34 submetacentric chromosomes plus one homomorphic pair (M/M) in males and one heteromorphic pair (M/SM) in females. A...
| Autores: | , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1997 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/230897 |
| Acceso en línea: | http://dx.doi.org/10.1508/cytologia.62.61 http://hdl.handle.net/11449/230897 |
| Access Level: | acceso abierto |
| Palabra clave: | Fish cytogenetics Imparfinis Sex chromosomes ZZ/ZW |
| Sumario: | The cytogenetic analysis of 21 specimens of Imparfinis mirini showed the presence of 2n = 58 chromosomes in animals of both sexes. The basic karyotype consists of 22 metacentric and 34 submetacentric chromosomes plus one homomorphic pair (M/M) in males and one heteromorphic pair (M/SM) in females. Ag-NORs were located interstitially on the long arms of the largest metacentric pair and differences were frequently found concerning NOR size in the homologues. I. mirini presents a relatively large quantity of constitutive heterochromatin located in pericentromeric, interstitial and telomeric positions in several chromosome pairs. The occurrence of a heteromorphic chromosome pair in females was demonstrable by the presence of one extra C-banded segment added to the long arm of the W chromosome. The occurrence of detectable heteromorphism involving the sex chromosomes among fishes is discussed. |
|---|