title: Occurrence of two cytotypes in Bryconamericus aff. iheringii (Characidae): karyotype analysis by C- and G-banding and replication bands.
abstract: Cytogenetic analyses of Bryconamericus aff. iheringii specimens from the upper Paraná River basin (State of Paraná, Brazil) are provided. They had 2n = 52 chromosomes and two cytotypes with variations in their karyotypic formulae: cytotype I with 12 metacentric, 18 submetacentric, 8 subtelocentric and 14 acrocentric chromosomes with a fundamental number (FN) of 90; cytotype II with 8 metacentric, 28 submetacentric, 6 subtelocentric and 10 acrocentric chromosomes with a fundamental number (FN) of 94. Differences in C- and G-band patterns between the cytotypes, distinguishing marker chromosomes for each karyotype, were reported. The R-band pattern by 5-bromodeoxyuridine incorporation was obtained in chromosomes of the cytotype II sample. In some metaphases, the second pair of submetacentric chromosomes is distinctive: its short arm is heterochromatic (positive C-band), corresponding to a late replication region. In the same cytotype, a G- and R-band size heteromorphism w as recorded in the long arm of pair 9 (submetacentric). These methodologies revealed an actual karyotypic differentiation in the B. aff. iheringii population analyzed. Morphometrical comparative analyses and a discussion of evolutionary aspects of chromosome diversification in species of this genus are provided as well.
authors: Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Av Colombo, 5790, 87020-900, Maringa, Parana, Brazil. albpcastro@nupelia.uem.br
authors: Ana Luiza
authors: AL
authors: de Brito Portela-Castro
authors: Horácio Ferreira
authors: HF
authors: Julio
authors: Isabel Cristina Martins
authors: IC
authors: Dos Santos
authors: Carla Simone
authors: CS
authors: Pavanelli
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002871:Chromosome Banding; D002875:Chromosomes; D004261:DNA Replication / Q000502:physiology; D005260:Female; D005399:Fishes / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D011110:Polymorphism, Genetic
chemical_list: D001973:Bromodeoxyuridine
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