Chromosomal location and distribution of As51 satellite DNA in five species of the genus Astyanax (Teleostei, Characidae, Incertae sedis) |
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| Authors: | D L Z Kantek M R Vicari W A M Peres M M Cestari R F Artoni L A C Bertollo and O Moreira-Filho |
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| Institution: | Departamento de Genética e Evolução, Laboratório de Citogenética, Universidade Federal de São Carlos, São Carlos, São Paulo 13565-905, Brazil; , Departamento de Biologia Estrutural Molecular e Genética, Laboratório de Citogenética e Evolução, Universidade Estadual de Ponta Grossa, Ponta Grossa, Paraná84030-900, Brazil; and Departamento de Genética, Universidade Federal do Paraná, Curitiba, Paraná81531-990, Brazil |
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| Abstract: | Constitutive heterochromatin makes up a substantial portion of the genome of eukaryotes and is composed mainly of satellite DNA repeating sequences in tandem. Some satellite DNAs may have been derived from transposable elements. These repetitive sequences represent a highly dynamic component of rapid evolution in genomes. Among the genus Astyanax , the As51 satellite DNA is found in species that have large distal heterochromatic blocks, which may be considered as derived from a transposable DNA element. In the present study, As51 satellite DNA was mapped through in situ fluorescent hybridization in the chromosomes of five species of the genus. The possible roles of this type of saltatory DNA type in the genome of the species are discussed, along with its use for the phylogenetic grouping of the genus Astyanax , together with other shared chromosomal characters. However, the number of As51 clusters is presented as a homoplastic characteristic, thereby indicating evident genomic diversification of species with this type of DNA. |
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| Keywords: | fish cytogenetics genome evolution karyotype diversification |
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