Cytogenetic characterization of the silverside fish Odontesthes regia (Humboldt, 1833) (Teleostei: Atheriniformes: Atherinopsidae) from Iquique, Chile

• Autor(a) principal: Muñoz, Carlos
• Data de Publicação: 2006
• Outros Autores: Nirchio, Mauro, Pérez, Julio E., Ron, Ernesto, Oliveira, Claudio [UNESP], Ferreira, Irani A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.revbiolmar.cl/index.php?option=com_content&view=article&id=329&Itemid=69&lang=en; http://hdl.handle.net/11449/68985
• topic: C-bands; FISH; Karyotype; NOR; chromosome; cytogenetics; karyotype; teleost; Chile; Iquique; South America; Tarapaca; Argentina elongata; Atheriniformes; Atherinopsidae; Odontesthes regia; Teleostei

This paper describes the karyotype of Odontesthes regia by means of Giemsa staining, C-banding, to reveal the distribution of the constitutive heterochromatin, and by Ag-staining and fluorescent in situ hybridization (FISH), to locate ribosomal genes (rDNA). The chromosome diploid modal count in the species was 2n = 48. The karyotype is composed of one submetacentric pair (pair 1), 16 subtelocentric pairs (pairs 2 to 17), and 7 acrocentric pairs (pairs 18 to 24). With the exception of pair 1 it was not possible to classify the homologous chromosomes accurately because differences in chromosome size were too slight between adjacent pairs. The distribution of C-banded heterochromatin allowed for a more accurate matching of the majority of chromosomes of the subtelocentric series. Silver staining of metaphase spreads allowed for the identification of Nucleolus Organizer Regions (Ag-NOR) on pair 1. FISH experiments showed that 18S rDNA sequences were located, as expected, in the same chromosome pair identified as the Ag-NOR-bearing one.