Biogeographic patterns in the chromosomal distribution of a satellite DNA in the banded tetra Astyanax fasciatus (Teleostei: Characiformes)

• Autor(a) principal: Kavalco, Karine Frehner
• Data de Publicação: 2013
• Outros Autores: Pazza, Rubens, Brandão, Karina de Oliveira, Almeida-Toledo, Lurdes Foresti de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1007/s13127-012-0100-8; http://www.locus.ufv.br/handle/123456789/22784
• topic: Astyanax fasciatus; Molecular cytogenetics; Karyotypic evolution; satDNA As-51

The As-51 satellite DNA is a transposon-like sequence formerly described for arthropods and physically identifiable by fluorescent in situ hybridization. In the present work, we describe the occurrence of this sequence, as well the C-banding and karyotype composition, in populations of the group Astyanax fasciatus from Mogi-Guaçu (Araras-SP), Paranapanema (Angatuba and Pilar do Sul-SP), Ribeira de Iguape (Sete Barras-SP) and Tietê (Indaiatuba and Salesópolis-SP) river basins. The specimens from Sete Barras (10 M + 20SM + 12ST + 6A) and Araras (8 M + 22SM + 12ST + 6A) have 2n = 48 chromosomes. The samples from Angatuba, Pilar do Sul and Indaiatuba presented 2n = 46 chromosomes (12 M + 20SM + 10ST + 4A). The individuals collected in Salesópolis showed three cytotypes, bearing 2n = 46 (12 M + 20SM + 10ST + 4A), 2n = 48 (8 M + 22SM + 12ST + 6A) and 2n = 50 (8 M + 16SM + 14ST + 12A). C-banding revealed large heterochromatic blocks at terminal chromosomal regions in all populations and/or cytotypes. All analyzed populations have conspicuous blocks carrying the As-51 satellite DNA, although the number of chromosomes bearing this repetitive sequence was variable among them. Such differences were not related to the diploid number of individuals, but rather to a biogeographic pattern. Aspects of the karyotype evolution and distribution of this sequence in distinct populations are discussed.