title: Chromosome Analyses of Apareiodon argenteus and Apareiodon davisi (Characiformes, Parodontidae): An Extensive Chromosomal Polymorphism of 45S and 5S Ribosomal DNAs.
abstract: This study analyzed two Apareiodon species without available chromosome data: Apareiodon argenteus and Apareiodon davisi. Both species have 54 metacentric/submetacentric chromosomes, with centromeric blocks of heterochromatin. Nucleolus organizer regions were active in chromosome pair 2 in A. argenteus and pairs 4 and 9 in A. davisi. In A. argenteus, 45S and 5S ribosomal genes were located in chromosome pairs 2 and 18, respectively. Polymorphisms were observed in these ribosomal sequences in A. davisi, with variations in the number/position of sites, and colocalization of these genes in some chromosome pairs. The WAp repetitive fraction was dispersed along the chromosomes of the two species. The satellite DNA pPh2004 was identified in chromosome pairs 7, 8, 10, 11, and 18 in A. argenteus and in pair 24 in A. davisi. The present study describes the first case of chromosomal polymorphisms involving two ribosomal sequences in Parodontidae and discusses the role of repetitive DNAs in the genome and karyotype diversity of this family.
authors.affiliation: 1 Departamento de Genética e Evolução, Universidade Federal de São Carlos , São Carlos-SP, Brazil .
authors.forename: Josiane Baccarin
authors.initials: JB
authors.lastname: Traldi
authors.affiliation: 2 Departamento de Biologia Estrutural, Molecular e Genética, Universidade Estadual de Ponta Grossa , Ponta Grossa-PR, Brazil .
authors.forename: Marcelo Ricardo
authors.initials: MR
authors.lastname: Vicari
authors.affiliation: 3 Universidade Tecnológica Federal do Paraná , Santa Helena-PR, Brazil .
authors.forename: Juliana de Fátima
authors.initials: Jde F
authors.lastname: Martinez
authors.affiliation: 3 Universidade Tecnológica Federal do Paraná , Santa Helena-PR, Brazil .
authors.forename: Daniel Rodrigues
authors.initials: DR
authors.lastname: Blanco
authors.affiliation: 4 Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná , Cascavel-PR, Brazil .
authors.forename: Roberto Laridondo
authors.initials: RL
authors.lastname: Lui
authors.affiliation: 1 Departamento de Genética e Evolução, Universidade Federal de São Carlos , São Carlos-SP, Brazil .
authors.forename: Orlando
authors.initials: O
authors.lastname: Moreira-Filho
mesh_terms: D000818:Animals; D060125:Characiformes / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D005260:Female; D059785:Karyotype; D008297:Male; D011110:Polymorphism, Genetic
chemical_list: D004275:DNA, Ribosomal