title: Chromosome mapping of repetitive sequences in Rachycentron canadum (Perciformes: Rachycentridae): implications for karyotypic evolution and perspectives for biotechnological uses.
abstract: The cobia, Rachycentron canadum, a species of marine fish, has been increasingly used in aquaculture worldwide. It is the only member of the family Rachycentridae (Perciformes) showing wide geographic distribution and phylogenetic patterns still not fully understood. In this study, the species was cytogenetically analyzed by different methodologies, including Ag-NOR and chromomycin A(3) (CMA(3))/DAPI staining, C-banding, early replication banding (RGB), and in situ fluorescent hybridization with probes for 18S and 5S ribosomal genes and for telomeric sequences (TTAGGG)(n). The results obtained allow a detailed chromosomal characterization of the Atlantic population. The chromosome diversification found in the karyotype of the cobia is apparently related to pericentric inversions, the main mechanism associated to the karyotypic evolution of Perciformes. The differential heterochromatin replication patterns found were in part associated to functional genes. Despite maintaining conservative chromosomal characteristics in relation to the basal pattern established for Perciformes, some chromosome pairs in the analyzed population exhibit markers that may be important for cytotaxonomic, population, and biodiversity studies as well as for monitoring the species in question.
authors.affiliation: Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Uedson Pereira
authors.initials: UP
authors.lastname: Jacobina
authors.forename: Marcelo de Bello
authors.initials: Mde B
authors.lastname: Cioffi
authors.forename: Luiz Gustavo Rodrigues
authors.initials: LG
authors.lastname: Souza
authors.forename: Leonardo Luiz
authors.initials: LL
authors.lastname: Calado
authors.forename: Manoel
authors.initials: M
authors.lastname: Tavares
authors.forename: João
authors.initials: J
authors.lastname: Manzella
authors.forename: Luiz Antonio Carlos
authors.initials: LA
authors.lastname: Bertollo
authors.forename: Wagner Franco
authors.initials: WF
authors.lastname: Molina
mesh_terms: D000818:Animals; D001483:Base Sequence; D001709:Biotechnology / Q000379:methods*; D002874:Chromosome Mapping / Q000379:methods*; D002875:Chromosomes / Q000235:genetics; D019143:Evolution, Molecular; D007621:Karyotyping; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D012270:Ribosomes / Q000235:genetics