Data/hora: 06/06/2024 11:43:17

Provedor de dados: | 74
País: | Brazil
Título: | Description of a ZZ/ZW sex chromosome system in Thoracocharax cf. stellatus (Teleostei, Characiformes, Gasteropelecidae)
Autores: | Carvalho,Margarida Lima; Oliveira,Claudio; Foresti,Fausto.
Data: | 2002-01-01
Ano: | 2002
Palavras-chave: | Sex chromosomes; ZW; DNA content; Fish; Evolution.
Resumo: | The family Gasteropelecidae is composed of three genera and eight species. This study shows that Thoracocharax cf. stellatus has 2n = 52 chromosomes for both sexes. The five males studied showed 8 metacentric, 16 submetacentric, 4 subtelocentric, and 24 acrocentric chromosomes; the seven females showed only one submetacentric chromosome, belonging to pair 11, and one extra acrocentric chromosome, smaller than all the other chromosomes, characterizing the presence of a ZZ/ZW sex chromosome system in this species. Nucleolus organizing regions (NORs) were detected on the short arms of the subtelocentric chromosome pair 13. Constitutive heterochromatin was identified at pericentromeric and terminal positions in almost all chromosomes. The W chromosome was almost entirely heterochromatic, except for a small terminal euchromatic segment. The analyses of the amount of nuclear DNA found 2.18 ± 0.09 pg of DNA per diploid nucleus, without significant differences between sexes. A discussion about the evolution of the sex chromosomes in this group is presented.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000300008
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572002000300008
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.25 n.3 2002
Fonte: | info:eu-repo/semantics/openAccess