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| Kavalco,Karine Frehner; Brandão,Karina de Oliveira; Pazza,Rubens; Almeida-Toledo,Lurdes Foresti de. |
| Four populations of Astyanax hastatus Myers 1928 from the Guapimirim River basin (Rio de Janeiro State) were analyzed and three distinct cytotypes identified. These cytotypes presented 2n = 50 chromosomes, with 4M+8SM+10ST+28A (Cytotype A), 8M+10SM+14ST+18A (Cytotype B), 6M+8SM+4ST+32A (Cytotype C) and scanty heterochromatin, mainly located throughout pericentromeric regions of several chromosomal pairs. No homologies with the As-51 satellite DNA were observed in the three cytotypes, although all of them presented multiple 18S rDNA sites, as detected by both silver nitrate staining and FISH (fluorescent in situ hybridization). The application of the term "species complex" in Astyanax is discussed from a cytotaxonomic viewpoint. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax hastatus; Molecular cytogenetics; Karyotypic evolution; Species complex. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000300009 |
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| Vicari,Marcelo Ricardo; Pazza,Rubens; Artoni,Roberto Ferreira; Margarido,Vladimir Pavan; Bertollo,Luiz Antonio Carlos. |
| Hoplias malabaricus (trahyra) is a widespread fish species over the Neotropical region with diversified inter-populational karyotypes (cytotypes), which may correspond to a species complex. Despite the wide distribution in the South American basins, some authors have questioned its natural origin in the Iguaçu river, an important Brazilian river basin which is characterized by several endemic fish species. We have analyzed the karyotype of H. malabaricus from different collection sites of this river, by conventional and banding methods. Our results, in addition to our previous data concerning geographic distribution of the cytotypes, contribute to better understand the origin of H. malabaricus on the Iguaçu river, reinforcing the proposition that it is a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome evolution; Karyotypes distribution; Endemism. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000300015 |
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| Kavalco,Karine Frehner; Pazza,Rubens; Bertollo,Luiz Antonio Carlos; Moreira-Filho,Orlando. |
| Cytogenetic data about satellite DNA distribution in four Astyanax species (Characidae) from the Paraitinga river, Paraíba do Sul river basin, Brazil, are presented. In order to characterize the constitutive heterochromatin, C-banding, chromomycin A3 and DAPI fluorescence staining, as well as fluorescence in situ hybridization (FISH) with the satellite DNA As-51 probe were performed. A. scabripinnis and A. parahybae presented 2n = 50 and 2n = 48 chromosomes, respectively. The heterochromatin was located in the pericentromeric and terminal regions of many chromosomes, corresponding to GC-positive regions and to the As-51 satellite DNA in terminal regions. A. intermedius and A. giton, both with 2n = 50 chromosomes, showed little heterochromatin, mostly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax; Fluorescence in situ hybridization (FISH); Heterochromatin; Karyotypic diversity; Satellite DNA. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000400005 |
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