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| Barreto,Silvia B.; Cioffi,Marcelo B.; Medrado,Aline S.; Silva,André T.; Affonso,Paulo R. A. M.; Diniz,Débora. |
| ABSTRACT Characiformes is the most cytogenetically studied group of freshwater Actinopterygii, but karyotypical data of several taxa remain unknown. This is the case of Nematocharax , regarded as a monotypic genus and characterized by marked sexual dimorphism. Therefore, we provide the first cytogenetic report of allopatric populations of Nematocharax venustus based on distinct methods of chromosomal banding and fluorescence in situ hybridization (FISH) with repetitive DNA probes (18S and 5S rDNA). The karyotype macrostructure was conserved in all specimens and populations, independently on sex, since they shared a diploid number (2n) of 50 chromosomes divided into 8m+26sm+14st+2a. The heterochromatin was mainly distributed at pericentromeric regions and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 18S rDNA; 5S rDNA; Coastal drainages; FISH; Population cytogenetics. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200205 |
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| Paim,Fabilene Gomes; Brandão,José Henrique Souza Galdino; Sampaio,Iracilda; Affonso,Paulo Roberto Antunes de Mello; Diniz,Débora. |
| Parrotfishes (Labridae, Scarinae) comprise a large marine fish group of difficult identification, particularly during juvenile phase when the typical morphology and coloration of adults are absent. Therefore, the goal of this study was to test cytogenetic markers and DNA barcoding in the identification of bucktooth parrtotfish Sparisoma radians from the northeastern coast of Brazil. Sequencing of cytochrome c oxidase subunit I (COI) confirmed all studied samples as S. radians, and all showed high similarity (99-100%) with Caribbean populations. The karyotype of this species was divergent from most marine Perciformes, being composed of 2n = 46 chromosomes. These consisted of a large number of metacentric and submetacentric pairs with small amounts of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: COI; Karyotype; South Atlantic fish; Ribossomal genes; Robertsonian rearrangements. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000500007 |
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| Diniz,Débora; Bertollo,Luiz A.C.. |
| Chromosomal studies were carried out on a population of the fish Hoplerythrinus unitaeniatus (jeju) from Prata river in the São Francisco river basin, Minas Gerais, Brazil using conventional Giemsa staining, C-banding, silver nitrate nucleolar organizer region (Ag-NOR) staining and fluorescent in situ hybridization (FISH) with 18S and 5S rDNA probes. We found a high degree of inter- and intra-individual variability with the identification of 2n = 50, 2n = 51 and 2n = 52 karyotypes at nearly the same frequency within the population. Intra-individual variation in chromosomal morphology and, consequently, karyotype formulae was also observed, chiefly in the specimens with 2n = 50 and 2n = 52 chromosomes. Ag-NORs and 18S rDNA sites also showed numerical and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotypes; C-banding; Nucleolar organizing regions; Intra- and inter-individual polymorphism. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000300009 |
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