Diversidade cromossômica e molecular no gênero Astyanax (Characiformes: Characidae)

• Autor(a) principal: Penteado, Pierre Rafael
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2248
• topic: Astyanax; Citogenética; Filogenia; Microssatélites; Astyanax; Cytogenetic; Phylogeny; Microsatellite; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA ANIMAL

The origin of the genus Astyanax, one of the most specious genera of the family Characidae is appointed as polyphyletic, with its current taxonomic status Incertae sedis.Morphologic, genetic and phylogeographic studies contribute to a better knowledge on the genus, which is considered a model. In this work, several species of different locations were studied using different approaches. Populations of the species complex A. aff fasciatus (São Francisco River Basin) and A. aff.hastatus(Coastal streams, Atlantic southeast) were investigated with the use of classic and molecular cytogenetics. A new cytotype with some shared features with the surrounding basins is described for the population of A. aff fasciatus from San Francisco Basin. Six SSR primers, a very informative molecular marker, previously isolated from Astyanaxmexicanus, were tested in five species distributed in the system of coastal drainages of the Atlantic Ocean. No amplification was achieved with one primer, while at least one primer was polymorphic in all species. Finally, the same population of A. aff.hastatus cytogenetically studied, collected in Angra dos Reis had the gene fragment of mtDNA ATPase 6 / 8 sequenced and included in a phylogenetic tree previously proposed for other coastal species population. Our data supports the hypothesis previously proposed that this population is actually a distinct species.