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| Registros recuperados: 70 | |
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| Pinhal,Danillo; Gadig,Otto BF; Wasko,Adriane P; Oliveira,Claudio; Ron,Ernesto; Foresti,Fausto; Martins,Cesar. |
| Sharks are suffering from intensive exploitation by worldwide fisheries leading to a severe decline in several populations in the last decades. The lack of biological data on a species-specific basis, associated with a k-strategist life history make it difficult to correctly manage and conserve these animals. The aim of the present study was to develop a DNA-based procedure to discriminate shark species by means of a rapid, low cost and easily applicable PCR analysis based on 5S rDNA repeat units amplification, in order to contribute conservation management of these animals. The generated agarose electrophoresis band patterns allowed to unequivocally distinguish eight shark species. The data showed for the first time that a simple PCR is able to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chondrichthyes; PCR; Species identification; 5S rDNA; Sharks. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200033 |
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| Azevedo,Marisa F.C.; Oliveira,Claudio; Pardo,Belén G.; Martínez,Paulino; Foresti,Fausto. |
| The fish order Pleuronectiformes, composed of 14 families, has two suborders: Psettodoidei (with one family) and Pleuronectoidei (with thirteen families). The relationships among families of Pleuronectoidei and among the genera of their families have extensively been debated and a consensus has not yet been reached. In the present study, partial sequences of the 12S and 16S mitochondrial rRNA genes were obtained from 19 species belonging to the families Achiridae, Bothidae, Cynoglossidae, Paralichthyidae, Pleuronectidae, Scophthalmidae, and Soleidae. Additional sequences of 42 pleuronectiform species were obtained from GenBank. Phylogenetic analyses were conducted by the methods of maximum-parsimony, maximum-likelihood and Bayesian inference. Our results... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phylogeny; Molecular systematics; Mitochondrial DNA; Fish evolution; Flatfishes. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200023 |
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| Hilsdorf,Silva; Oliveira,Claudio; Lima,Flávio César Thadeo de; Matsumoto,Cristianne Kayoko. |
| The genus Brycon, the largest subunit of the Bryconinae, has 42 valid species distributed from southern Mexico to the La Plata River in Argentina. Henochilus is a monotypic genus, comprising a single species (H. wheatlandii) found in the upper Rio Doce basin. In the present study, partial sequences of the mitochondrial gene 16S were obtained for fifteen species of Brycon and for Henochilus wheatlandii. The results showed that the genus Brycon is paraphyletic, since Henochilus is the sister-group of B. ferox and B. insignis. The most basal species analyzed were the trans-Andean species B. henni, B. petrosus, and B. chagrensis. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phylogeny; Molecular systematics; Mitochondrial DNA; Fish evolution; Systematic. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200034 |
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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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| Nirchio,Mauro; Martinez,Emanuel Ricardo Monteiro; Foresti,Fausto; Oliveira,Claudio. |
| Despite their ecological and economical importance, fishes of the family Ariidae are still genetically and cytogenetically poorly studied. Among the 133 known species of ariids, only eight have been karyotyped. Cytogenetic analyses performed on Genidens barbus and Sciades herzbergii revealed that both species have 2n = 56 chromosomes and Cathorops aff. mapale has 2n = 52 chromosomes: Genidens barbus has 10 Metacentrics (M), 14 Submetacentrics (SM), 26 Subtelocentrics (ST), and 6 Acrocentrics (A), Sciades herzbergii has 14M, 20SM, 18ST and 4A, whereas Cathorops aff. mapale has 14M, 20SM, and 18ST. The nucleolus organizer regions (NORs) were found in a single chromosome pair on the short arm of a large-sized ST pair in Genidens barbus and on the short arm of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; Ag-NORs; Chromosome evolution; Chromosome rearrangements; Fish. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200011 |
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| Carvalho,Margarida Lima; Oliveira,Claudio; Foresti,Fausto. |
| The family Gasteropelecidae is composed of three genera and eight species. This study shows that Thoracocharax cf. stellatus has 2n = 52 chromosomes for both sexes. The five males studied showed 8 metacentric, 16 submetacentric, 4 subtelocentric, and 24 acrocentric chromosomes; the seven females showed only one submetacentric chromosome, belonging to pair 11, and one extra acrocentric chromosome, smaller than all the other chromosomes, characterizing the presence of a ZZ/ZW sex chromosome system in this species. Nucleolus organizing regions (NORs) were detected on the short arms of the subtelocentric chromosome pair 13. Constitutive heterochromatin was identified at pericentromeric and terminal positions in almost all chromosomes. The W chromosome was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sex chromosomes; ZW; DNA content; Fish; Evolution. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000300008 |
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| Maistro,Edson Luis; Foresti,Fausto; Oliveira,Claudio. |
| The absence of longitudinal bands in fish chromosomes has been associated with technical problems in chromosome preparations or the absence of a structural compartmentalization in the fish genome. In the present study, a R-banding pattern was obtained using a replication banding technique by in vivo treatment with 5-bromodeoxyuridine (5-BrdU). G-banding patterns were obtained after trypsin treatment and also after chromosome cleavage by in situ treatment with the restriction endonuclease BamHI. A similar G-banding pattern was also obtained after cleavage with the endonuclease HinfI. Presence of a resolute R- and G-banding patterns shows that Astyanax scabripinnis paranae chromosomes could present an isochore-like structure similar to that found in other... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200011 |
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| Abreu,Marcia Matos de; Pereira,Luiz Henrique Garcia; Vila,Vilma Barretto; Foresti,Fausto; Oliveira,Claudio. |
| Catfishes of the genus Pseudoplatystoma are very important species due to both their high commercial value and their ecological role as voracious predators. They undertake lengthy migratory movements during their life-cycle, this including reproductive migration which occurs from October to December in the rainy season. In the present study, seven microsatellite loci were analyzed to access genetic variability in two samples of P. reticulatum from the Upper Paraguay Basin. The loci were highly polymorphic (mean = 7.28). According to all analysis, the two samples of P. reticulatum revealed pronounced genetic differentiation. Fst value was 0.2290, Rst value 0.1067 and AMOVA 22.90% (Fst) and 10.67% (Rst), all being highly significant (p < 0.001). The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Population genetics; Microsatellite; Homing; Population structure. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400032 |
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| Maistro,Edson Luis; Oliveira,Claudio; Foresti,Fausto. |
| Among four specimens of Astyanax scabripinnis sympatrically collected from the Tamanduá stream (State of São Paulo, Brazil), three, named cytotype I, had 2n = 50 chromosomes (6M + 26SM + 4ST + 14A) and a fundamental number (FN) of 86, and one specimen, named cytotype II, had 2n = 48 chromosomes (6M + 28SM + 4ST + 10A) and FN = 86. Besides the difference in diploid number, the cytotypes showed a clear difference in the distribution of constitutive heterochromatin. One NOR-bearing chromosome pair was detected in both cytotypes and one specimen of cytotype I had multiple NORs (tree chromosome pairs). Robertsonian translocations and an increase or loss of heterochromatin are proposed to explain the karyotypic divergence observed. Some aspects related to the... |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200021 |
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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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| Martinez,Emanuel Ricardo Monteiro; Nirchio,Mauro; Granado,Angel; Foresti,Fausto; Oliveira,Claudio. |
| Cytogenetic analyses performed in Cephalosilurus apurensis, Microglanis aff. cottoides and Pseudopimelodus bufonius revealed that the three species have 2n = 54 chromosomes: C. apurensis presented six metacentric (M), 28 submetacentric (SM), 14 subtelolocentric (ST), and six acrocentric (A) chromosomes, while M. aff. cottoides showed 10M, 32SM, 10ST and 2A, and P. bufonius had 12M, 30SM and 12ST. The nucleolus organizer regions (NORs) were present on the short arm of a middle-sized ST pair, identified as pair 19, in C. apurensis NORs were found on the short arm of a middle-sized ST (pair 23) and on the long arm of a middle-sized ST (pair 22) in M. aff. cotttoides and on the short arm of three middle-sized ST pairs, identified as pairs 9, 10 and 11, in P.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Chromosomes; C-banding; Ag-NOR; Fish. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000400015 |
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| Alves,Anderson Luis; Porto-Foresti,Fábio; Oliveira,Claudio; Foresti,Fausto. |
| Cytogenetic analyses carried out in eight specimens of Sphoeroides spengleri revealed the presence of 2n = 46 chromosomes (20 M/SM and 26 ST/A). Besides the standard karyotypical set, the presence of B microchromosomes was observed in two individuals, ranging from 0 to 2 microchromosomes per cell. A karyotype composed by 2n = 46 chromosomes with occurrence of M and SM chromosomes is considered basal for the species from the clade comprising the families Tetraodontidae, Balistidae, and Diodontidae, although it represents a derived condition for the order Tetraodontiformes, whose basal karyotype would be composed by 2n = 48 acrocentric chromosomes. The occurrence of B microchromosomes in marine Tetraodontiformes fish was not known, and this represents the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: B chromosome; Pufferfish; Sphoeroides spengleri. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200014 |
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| Registros recuperados: 70 | |
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