Nucleotide sequence, genomic organization and chromosome localization of 5S rDNA in two species of Curimatidae (Teleostei, Characiformes)
The 5S ribosomal DNA (5S rDNA) of higher eukaryotes is organized in repeat units of tandem arrays composed of a 5S rDNA coding region, conserved even among non-related taxa, and a variable non-transcribed spacer sequence (NTS). To contribute to knowledge on the organization and evolution of vertebra...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/30483 |
| Acceso en línea: | http://dx.doi.org/10.1590/S1415-47572006000200009 http://hdl.handle.net/11449/30483 |
| Access Level: | acceso abierto |
| Palabra clave: | Cyphocharax modesta Steindachnerina insculpta 5S rDNA chromosomes FISH nucleotide sequence |
| Sumario: | The 5S ribosomal DNA (5S rDNA) of higher eukaryotes is organized in repeat units of tandem arrays composed of a 5S rDNA coding region, conserved even among non-related taxa, and a variable non-transcribed spacer sequence (NTS). To contribute to knowledge on the organization and evolution of vertebrate 5S rDNA we used PCR, nucleotide sequencing, Southern blot hybridization and chromosome fluorescence in situ hybridization (FISH) to investigate 5S rDNA tandem repeats in the South American Curimatidae fish Steindachnerina insculpta and Cyphocharax modesta. 5S rDNA repeats of 180 base pairs (bp) from both species were PCR-generated and sequenced evidencing the shortest 5S rDNA monomer so far described in eukaryote species. Southern blotting revealed that both species contained two tandem 5S rDNA classes, the PCR amplified fragment composed of 180 bp monomers and a class of 1600 bp monomers not detected by PCR. Chromosome mapping of the 5S rDNA repeats identified a major locus in both species and a second minor locus only in C. modesta. The Southern blot and chromosome mapping data indicate the presence of different types of 5S rDNA tandem repeats in the Curimatidae genome. |
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