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| Registros recuperados: 20 | |
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| Porto-Foresti,Fábio; Oliveira,Claudio; Tabata,Yara A.; Rigolino,Marcos G.; Foresti,Fausto. |
| In salmonid species, nucleolar organizing regions (NORs) have frequently been found on a single chromosome pair. However, some other, smaller yet active NORs have also been described. In the present study, NORs were found to be located in different positions on the chromosomes of 12 rainbow trout samples (11 cultivated and one naturalized stocks). Three phenotypes were found: 1) NORs located on two submetacentric chromosomes, in a subterminal position on the short arm (AA); 2) NORs located on two submetacentric chromosomes, in a subterminal position on the long arm (BB); and 3) NORs located on two submetacentric chromosomes, one in a subterminal position on the short arm, and the other in a subterminal position on the long arm (AB). Phenotype AA was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: NOR polymorphism; Fish cytogenetics; Rainbow trout. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000400009 |
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| Pires,Larissa Bettin; Usso,Mariana Campaner; Giuliano-Caetano,Lucia; Dias,Ana Lúcia. |
| Abstract The genera Cichlasoma and Gymnogeophagus belong to the subfamily Cichlinae, the only one in Neotropical cichlids. Cichlasoma dimerus, C. paranaense, C. portalegrense, Gymnogeophagus rhabdotus, and G. lacustris were collected at different points in the Paranapanema and Paraguay basins and the Lagoon of Patos hydrographic system. In addition to conventional analysis, CMA3 fluorochrome staining, and FISH with 18S rDNA probe were performed. All species had a diploid number equal to 48, with interand intraspecific differences in karyotype formulae. All species presented a single AgNOR site, except G. rhabdotus and the C. paranaense population of the Paranapanema River, which revealed more than one pair of nucleolar chromosomes. AgNORs were coincident... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome banding; Fish cytogenetics; Karyotype diversification; Ribosomal DNA. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000400203 |
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| Vicari,Marcelo Ricardo; Almeida,Mara Cristina de; Bertollo,Luiz Antonio Carlos; Moreira-Filho,Orlando; Artoni,Roberto Ferreira. |
| We used differential staining techniques (BSG, GTG, AgNO3, DAPI and CMA3 banding) and fluorescent in situ hybridization (FISH) with 5S and 18S probes to investigated the karyotypic and cytogenetic chracteristics of Prochilodus lineatus specimens from a population in Vila Velha state park (Parque Estadual de Vila Velha, Ponta Grossa, Paraná state, southern Brazil). The specimens studied showed the same karyotype as that found in other P. lineatus populations, i.e. 2n = 54 biarmed chromosomes (40m + 14 sm) and c-positive heterochromatin preferentially located pericentromerically in all chromosomes. The presence of partial or totally heterochromatic supernumerary chromosomes with numeric intra-individual variation was confirmed in the analyzed population. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish cytogenetics; Prochilodus; Karyotype; Minor and major rDNA; NOR polymorphism. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000400008 |
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| Rocha,Érika Cruz; Molina,Wagner Franco. |
| The Lutjanidae or snappers are a family of perciform fishes, mainly marine but with some members living in estuaries and entering fresh water to feed. Some are important food fish. Cytogenetic data for Lutjanidae are scarce. In the present work, we cytogenetically characterized through conventional Giemsa staining techniques, Ag-NOR and C-banding the species Ocyurus chrysurus, Lutjanus analis, L. alexandrei, L. cyanopterus, L. jocu and L. synagris, all found along the Brazilian coast. Karyotype analysis of all six species showed a modal value of 2n = 48 acrocentric chromosomes. Single NORs were found at pericentromeric position on the long arms of the 2nd pair in O. chrysurus, L. alexandrei and L. cyanopterus, on the 5th pair in L. analis and on the 23rd... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome evolution; Fish cytogenetics; Lutjanidae; Lutjanus; Ocyurus. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000300011 |
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| Garcia,Caroline; Moreira Filho,Orlando. |
| Karyotypes and other chromosomal markers were investigated in three species of the catfish genus Pimelodus, namely P. fur, P. maculatus and Pimelodus sp., from municipality of Três Marias, Minas Gerais, Brazil, using differential staining techniques (C-banding, Silver nitrate and CMA3 staining). The diploid chromosome number was 2n = 56 in P. maculatus and Pimelodus sp., while in P. fur 2n = 54. The karyotype of P. fur consisted in 32M + 8SM + 6ST + 8A with fundamental number (NF) of 100, that of P. maculatus 32M + 12SM + 12A with NF = 112, and that of Pimelodus sp. had 32M + 12Sm + 6ST + 6A with NF = 106.The nucleolar organizer regions (NORs) in all three species were invariably detected in telomeres of longer arm of the 20th chromosome pair. These sites... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish cytogenetics; Diploid number reduction; Chromosomal rearrangements; Chromosome banding; Catfishes. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000200006 |
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| Vasconcelos,Antonio Jales Moraes; Molina,Wagner Franco. |
| The order Anguilliformes comprises 15 families, 141 genera and 791 fish species. Eight families had at least one karyotyped species, with a prevalence of 2n = 38 chromosomes and high fundamental numbers (FN). The only exception to this pattern is the family Muraenidae, in which the eight species analyzed presented 2n = 42 chromosomes. Despite of the large number of Anguilliformes species, karyotypic reports are available for only a few representatives. In the present work, a species of Ophichthidae, Myrichthys ocellatus (2n = 38; 8m+14sm+10st+6a; FN = 70) and four species of Muraenidae, Enchelycore nigricans (2n = 42; 6m+8sm+12st+16a; FN = 68), Gymnothorax miliaris (2n = 42; 14m+18sm+10st; FN = 84), G. vicinus (2n = 42; 8m+6sm+28a; FN = 56) and Muraena... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anguilliformes; Fish cytogenetics; Muraenidae; Ophichthidae. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000100012 |
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| Nirchio,Mauro; Oliveira,Claudio; Ferreira,Irani Alves; Granado,Angel; Ron,Ernesto. |
| The karyotype and chromosomal characteristics of the characid fish Triportheus venezuelensis were investigated using differential staining techniques (C-banding, Ag-NOR staining) and fluorescent in situ hybridization (FISH) with an 18S rDNA probe. The diploid chromosome number (2n = 52), karyotype composition and sex chromosome determination system of the ZZ/ZW type were the same as previously described in other species of the genus Triportheus. However, extensive variation regarding nucleolus organizer regions (NOR) different from other species was observed. 18S rDNA sequences were distributed on nine chromosome pairs, but the number of chromosomes with Ag-NORs was usually lower, reaching a maximum of four chromosomes. When sequential staining experiments... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 18S rDNA; Ag-NORs; C-band; FISH; Fish cytogenetics; Sex chromosomes. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100007 |
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| Fernandes,Carlos Alexandre; Aguiar,Allan Kardec Moreira de; Paiz,Leonardo Marcel; Baumgärtner,Lucas; Piscor,Diovani; Margarido,Vladimir Pavan. |
| ABSTRACT Gymnorhamphichthys britskii is a Neotropical electric fish of family Rhamphichthyidae described from the Paraná-Paraguay system. This study reports the first karyotypic description of G. britskii collected from the upper Paraná river basin, which presented 2n=38 chromosomes, karyotype composed of 14 metacentric, 8 submetacentric, 2 subtelocentric and 14 acrocentric chromosomes, and fundamental number as 62 for both sexes. Heteromorphic sex chromosomes were absent. A single pair of nucleolar organizing regions (NORs) was detected in the submetacentric chromosome pair number 9 by silver staining and confirmed by the 18S rDNA probe. The 5S rDNA was located in a single chromosome pair. Heterochromatic regions were clearly observed in the short arms of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ag-NORs; C-banding; Fish cytogenetics; Karyotype evolution; Repetitive sequences. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000300205 |
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| Hashimoto,Diogo Teruo; Gonçalves,Vanessa Regina; Bortolozzi,Jehud; Foresti,Fausto; Porto-Foresti,Fábio. |
| Several species of the genus Astyanax have already been genetically studied, and B-chromosomes have been considered to be an interesting feature in some species of this group. In the present paper we report, for the first time, the occurrence of a B microchromosome in a natural population of A. altiparanae. This additional genomic element was identified as an acrocentric chromosome, similar in size to the smallest chromosomal pairs of the standard karyotype. Analysis of the constitutive heterochromatin pattern by C-banding evidenced heterochromatic blocks located on centromeric, pericentromeric, and interstitial regions of some chromosomes, and also positive marks in a subtelocentric chromosomal pair that presented the short arms entirely heterochromatic.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: B chromosomes; Fish cytogenetics; Astyanax altiparanae. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200021 |
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| Utsunomia,Ricardo; Pansonato-Alves,José C.; Costa-Silva,Guilherme J.; Mendonça,Fernando F.; Scacchetti,Priscilla C.; Oliveira,Claudio; Foresti,Fausto. |
| The fish species Synbranchus marmoratushas been reported to exist as a species complex due to high intraspecific karyotypic variability in spite of the difficulty or impossibility to distinguish them using morphological traits alone. The goal of this work was to use cytogenetic and molecular methods to determine the species delimitations and understand the karyoevolution ofS. marmoratususing samples collected from distinct Brazilian localities. Among the analyzed specimens, a large degree of cytogenetic variation related to diploid numbers and karyotype structure was observed, with karyotypes showing 2n=42, 44 and 46 chromosomes. In addition, using sequences of three mitochondrial genes, the phylogenetic relationships between every sample with a known... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomal diversity; Fish cytogenetics; Karyotype evolution; Repetitive DNA; Species complex. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000400903 |
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| Registros recuperados: 20 | |
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