Evidências moleculares dos padrões evolutivos e filogeográficos de populações de Astyanax paranae (Pisces : Characidae) com base em caracteres do DNA mitocondrial
Carregando...
Data
2011-02-24
Autores
Marreta, Maria Eduarda [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Astyanax paranae é uma espécie de peixe de pequeno porte que habita cabeceiras de riachos, resultando no isolamento geográfico entre as populações. Sendo considerada endêmica da bacia do Alto rio Paraná, recentemente foi elevada a espécie, deixando de ser considerada uma subespécie de A. scabripinnis, sendo a única espécie do “complexo scabripinnis” presente nessa bacia. Os raros relatos de dados moleculares populacionais e a ausência de uma análise filogeográfica consistente para populações de A. paranae, aliado as evidências citogenéticas e morfológicas de que essa espécie não represente uma unidade monofilética, reforçam a necessidade de um amplo estudo evolutivo e biogeográfico na bacia do Alto rio Paraná, reconhecidamente uma área de endemismo ictiológico. Nesse sentido, caracterizou-se a variabilidade genética em populações de A. paranae a fim de se estabelecer as relações filogenéticas e filogeográficas entre as linhagens de DNA na bacia do Alto rio Paraná, através da identificação dos haplótipos do mtDNA a partir da sequência completa do gene da ATP sintetase 6 e 8 (ATPase 6/8), num total de 842pb, bem como a caracterização das quatro espécies mais abundantes dessa bacia por PCR-RFLP. As análises filogenéticas foram realizadas com 88 exemplares de A. paranae além de 70 exemplares de espécies relacionadas do gênero, num total de 158 indivíduos analisados. Como grupo externo foram incluídos exemplares de Serrapinnus e Bryconamericus. As topologias foram geradas a partir dos métodos de Neighbor Joining, Máxima Parcimônia, no programa PAUP 4.0b10, e Inferência Bayesiana, no programa Mr. Bayes, enquanto a rede de haplótipo foi gerada no programa TCS. O relógio molecular foi utilizado para estimar o tempo de divergência entre as espécies/linhagens adotando a taxa de 1.3%/Ma para o gene ATPase 6/8. Tanto as análises filogenéticas...
Astyanax paranae is small sized species of fish that inhabit small headwater streams, resulting in geographical isolation between populations. Being considered endemic to the Upper Paraná River basin it was considered a species and no longer a subspecies of A. scabripinnis, being the only one species of the “scabripinnis complex” present in this basin. The few reports of molecular population data and the absence of a consistent phylogeographic analysis for populations of A. paranae, combined to cytogenetic and morphological evidences that this species does not represent a monophyletic unit, reinforce the need of a wide study of evolution and biogeography in the Upper Paraná River basin, a known area of ichthyological endemism. The genetic variability in populations of A. paranae was characterized in order to establish phylogenetic and phylogeographic relationships between mtDNA lineages in the Upper Paraná River basin, through the identification of mtDNA haplotypes from the complete sequence of the gene ATP synthase 6 and 8 (ATPase 6/8), a total of 842bp, and the characterization of the four most abundant species in this basin by PCR-RFLP. Phylogenetic analyses were made in 88 specimens of A. paranae and also in 70 of related species of the genus, resulting in 158 individuals analyzed. As outgroup, were included samples of Serrapinnus and Bryconamericus. The topologies were generated from the methods of Neighbor Joining, Maximum Parsimony and Bayesian Inference in the program PAUP 4.0b10, while the haplotype network was generated in the program TCS. The molecular clock was used to estimate time of divergence between species/lineage using the rate of 1.3%/Ma for the ATPase 6/8 gene. Both phylogenetic and phylogeographic analysis support the hypothesis that A. paranae does not form a monophyletic unit in the Upper Paraná River basin, being possible to identify seven... (Complete abstract click electronic access below)
Astyanax paranae is small sized species of fish that inhabit small headwater streams, resulting in geographical isolation between populations. Being considered endemic to the Upper Paraná River basin it was considered a species and no longer a subspecies of A. scabripinnis, being the only one species of the “scabripinnis complex” present in this basin. The few reports of molecular population data and the absence of a consistent phylogeographic analysis for populations of A. paranae, combined to cytogenetic and morphological evidences that this species does not represent a monophyletic unit, reinforce the need of a wide study of evolution and biogeography in the Upper Paraná River basin, a known area of ichthyological endemism. The genetic variability in populations of A. paranae was characterized in order to establish phylogenetic and phylogeographic relationships between mtDNA lineages in the Upper Paraná River basin, through the identification of mtDNA haplotypes from the complete sequence of the gene ATP synthase 6 and 8 (ATPase 6/8), a total of 842bp, and the characterization of the four most abundant species in this basin by PCR-RFLP. Phylogenetic analyses were made in 88 specimens of A. paranae and also in 70 of related species of the genus, resulting in 158 individuals analyzed. As outgroup, were included samples of Serrapinnus and Bryconamericus. The topologies were generated from the methods of Neighbor Joining, Maximum Parsimony and Bayesian Inference in the program PAUP 4.0b10, while the haplotype network was generated in the program TCS. The molecular clock was used to estimate time of divergence between species/lineage using the rate of 1.3%/Ma for the ATPase 6/8 gene. Both phylogenetic and phylogeographic analysis support the hypothesis that A. paranae does not form a monophyletic unit in the Upper Paraná River basin, being possible to identify seven... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Peixe, Filogenia, Genética, Filogeografia, Parana, Rio, Phylogeny, Phylogeography, Upper Paraná River
Como citar
MARRETA, Maria Eduarda. Evidências moleculares dos padrões evolutivos e filogeográficos de populações de Astyanax paranae (Pisces : Characidae) com base em caracteres do DNA mitocondrial. 2011. 95 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2011.