Artículos de revistas
Cytogenetic characterization of distinct B chromosomes in a population of the fish Astyanax bockmanni (Teleostei, Characiformes)
Fecha
2012-01-01Registro en:
Caryologia. Florence: Univ Florence Botany Inst, v. 65, n. 3, p. 229-233, 2012.
0008-7114
10.1080/00087114.2012.738488
WOS:000311452000009
3815338174165832
Autor
Universidade Estadual Paulista (Unesp)
Institución
Resumen
Individuals of Astyanax bockmanni from one population belonging to the Paranapanema River basin, southeastern Brazil, were cytogenetically examined. In the present paper, we report a diploid number of 50 chromosomes, with some individuals bearing additional chromosomes, characterized as different variants of B chromosomes. The B microchromosome of acrocentric morphology (B-a) was the most frequent type in this population (77.7%). Two other variants were identified as metacentric B chromosomes, but of distinct sizes, characterized as macrochromosome (B-M) and microchromosome (B-m). Conspicuous heterochromatic blocks were observed in the terminal regions of some chromosomes of the standard karyotype and partially heterochromatic blocks were detected in all B chromosomes. 18S ribosomal RNA genes were distributed in the terminal region of several chromosomes, but were not located on the B chromosomes.