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Registros recuperados: 52 | |
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Santos,Natália M.; Ferreira-Neto,Maressa; Artoni,Roberto F.; Vicari,Marcelo R.; Bakkali,Mohammed; Oliveira,Claudio de; Foresti,Fausto. |
Individual samples from five populations of the characid fish Astyanax scabripinnis (Jenyns, 1842) from the Tietê and Paranapanema river basins (Brazil) were studied. All individuals analyzed presented 50 chromosomes but three different karyotypic forms were observed. Additionally, some individuals of one karyomorph presented a macro supernumerary chromosome. No chromosomal differentiation was observed between males and females in any sample analyzed. C-banding revealed two distinct distribution patterns in these populations in which strong terminally located heterochromatic blocks were detected in the long arms of some chromosomes of the specimens from Cascatinha, Cintra, and Funari streams, whereas populations of the Capão Bonito stream and the Barbosa... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome markers; Karyoevolution; Karyomorphs; Nucleolus organizer region. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702012000200008 |
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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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Orsi,Mário Luís; Carvalho,Edmir Daniel; Foresti,Fausto. |
O objetivo desse trabalho foi a determinação da estrutura populacional da espécie. Foram escolhidos quatro locais de amostragem com características ambientais distintas na bacia do rio Tibagi. As amostragens foram realizadas mensalmente no período de janeiro de 1997 a fevereiro de 1998. Um total de 1553 indivíduos foram capturados, apresentando constância em todos os trechos, com as maiores abundâncias nos trechos do rio Congonhas (76 %). Variações ocorreram entre os trechos por fase de desenvolvimento e classes de comprimento e na distribuição espacial, demonstrando que a espécie apresenta estrutura populacional diferenciada. A espécie apresentou grande capacidade adaptativa exploratória, utilizando estratégias diferenciadas na estrutura da população. A... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ecologia; Peixes; Tibagi. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752004000200008 |
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Maistro,Edson Luis; Oliveira,Claudio; Foresti,Fausto. |
Cytogenetic and morphological studies were carried out on nine local populations of Astyanax scabripinnis paranae. All populations exhibited 2n = 50 chromosomes as well as conspicuous differences involving karyotype morphology, number and position of nucleolar organizer regions (NORs) and amount and/or locations of constitutive heterochromatin blocks. A quantitative study of the cytogenetic data showed that eight populations possessed different karyotypes. Morphological analyses based on nine measurements and two meristic parameters were effective in establishing clear identification of five populations. Comparative analysis of cytogenetic and morphological traits suggests that chromosomal changes have occurred at a more rapid rate than morphological... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571998000200005 |
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Ninhaus-Silveira,Alexandre; Foresti,Fausto; Tabata,Yara Aiko; Rigolino,Marcos Guilherme; Veríssimo-Silveira,Rosicleire. |
Cryopreservation of semen from sex-reversed females of rainbow trout aims at rationalizing the production of stocks composed by 100% females. Semen from normal males (M) and two types of genotypic females (R and G), sex-reversed by the oral administration of 17alpha-methyltestosterone, were used. R was obtained by the fertilization of normal eggs with semen of sex-reversed females while G via gynogenetic reproduction. Semen was diluted in an extender solution (glucose 5,4 g, egg yolk 10 ml, dimetil sulfoxide 10 ml, water 80 ml) at 1:3 ratio (semen/extender), stored in straws of 0.5 ml and freezed in a dry container Cryopac CP-65, at -180ºC. Thawing was performed with water at 70ºC for 3 seconds. There were no significant fertilization rate differences... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oncorhynchus mykiss; Cryopreservation; Sex reversal; Gynogenesis; Semen. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000100009 |
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Martinez,Emanuel Ricardo Monteiro; Zawadzki,Claudio Henrique; Foresti,Fausto; Oliveira,Claudio. |
In this work, we analyzed the karyotypes of five species. Hypostomus cf. heraldoi, from the Mogi-Guaçu River, had 2n = 72 chromosomes, with a nucleolar organizer region (NOR) in one chromosomal pair. Hypostomus regani, from the Mogi-Guaçu River had 2n = 72 chromosomes with NORs in two chromosomal pairs. Hypostomus sp., from the Mogi-Guaçu River basin, had 2n = 68 chromosomes, with NORs in two chromosomal pairs. Hypostomus aff. agna, from Cavalo Stream, had 2n = 74 chromosomes with NORs in two chromosomal pairs. Hypostomus cf. topavae, from Carrapato Stream, had 2n = 80 chromosomes, with NORs in two chromosomal pairs. Hypostomus species showed marked diversity in the karyotypic formula, which suggested the occurrence of several Robertsonian rearrangements... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; Evolution; Hypostominae; Neotropical fish; NOR. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000400006 |
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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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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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Prado,Fernanda Dotti do; Nunes,Tatiana Leite; Senhorini,José Augusto; Bortolozzi,Jehud; Foresti,Fausto; Porto-Foresti,Fábio. |
The cytogenetic characteristics of Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum and their F1, F2 and backcross hybrids were assessed by using chromosome banding techniques. The diploid number of 56 chromosomes was constant in all species and lineages, with a karyotypic formula containing 20 metacentric, 12 submetacentric, 12 subtelocentric and 12 acrocentric chromosomes. Nucleolar organizer regions (NORs) were identified in two subtelocentric chromosomes in the parents and hybrids, with partial nucleolar dominance in F1 and F2 specimens. Heterochromatic blocks were detected in the terminal and centromeric regions of some chromosomes in all individuals. For parental and hybrid lineages, 18S ribosomal clusters corresponding to NORs and 5S... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Backcrossing; Cytogenetics; Interspecific hybrids; Post-F1 hybrids; Pseudoplatystoma. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100008 |
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Fonteles,Soraia B.A.; Lopes,Carlos E.; Akama,Alberto; Fernandes,Flora M.C.; Porto-Foresti,Fábio; Senhorini,José A.; Daniel-Silva,Maria de Fátima Z.; Foresti,Fausto; Almeida-Toledo,Lurdes Foresti de. |
A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs) were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome; Fish; Gymnotidae; Electric eel. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200010 |
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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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Registros recuperados: 52 | |
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