Data/hora: 09/06/2024 18:17:29

Provedor de dados: | 74
País: | Brazil
Título: | Comparative cytogenetics among species of the Astyanax scabripinnis complex: evolutionary and biogeographical inferences
Autores: | Vicari,Marcelo Ricardo; Noleto,Rafael Bueno; Artoni,Roberto Ferreira; Moreira-Filho,Orlando; Bertollo,Luiz Antonio Carlos.
Data: | 2008-01-01
Ano: | 2008
Palavras-chave: | Karyotype evolution; Cytotaxonomy; RDNA sites; Biogeography.
Resumo: | Karyotype data are presented for distinct species of the genus Astyanax from four rivers belonging to three different hydrographic basins of the State of Paraná, Brazil (Verde River - Tibagi basin, Açungui River - Ribeira basin, and Santo Antônio and Jaguariaíva Rivers - Jaguariaíva basin). Three karyotypic forms were identified, here denominated karyotype A (2n = 50 chromosomes, with 8m+18sm+10st+14a, and thirteen 18S rDNA sites); karyotype B (2n = 50 chromosomes, with 8m+18sm+10st+1f4a, and four 18S rDNA sites); and karyotype C (2n = 48 chromosomes, with 10m+16sm+10st+12a, and eight 18S rDNA sites). The pattern of constitutive heterochromatin was similar among the three karyotypic forms, with few differences. The 5S rDNA corresponds to a synapomorphic character regarding its number and chromosomal localization. The karyotypic form A occurs in the distribution center of the type locality of A. paranae, in the proximities of the town of Castro (Tibagi basin), and may have reached the headwaters of the Ribeira River by the breakdown of geographical barriers. The karyotypic forms B and C are sympatric and syntopic, occurring solely in the Jaguariaíva River basin. Our hypothesis is that the karyotypic form A corresponds to the species A. paranae and forms B and C correspond to other species of the A. scabripinnis complex.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200002
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572008000200002
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.31 n.1 suppl.0 2008
Fonte: | info:eu-repo/semantics/openAccess