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Registros recuperados: 52 | |
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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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Ninhaus-Silveira,Alexandre; Foresti,Fausto; Veríssimo-Silveira,Rosicleire; Senhorini,José Augusto. |
Aiming to improve fish reproduction techniques, the characterization and cryopreservation of semen of Brycon cephalus were performed. The seminal characteristics observed were: an almost transparent, milky semen with a mean volume of 4mL, and sperm concentration of 9.617±1.630 x 10(6) spermatozoa/mm³. Spermatozoa (length = 31.288 ±4.47µm) were of the aquasperm type and displayed a small, round head (length = 1.727 ±0.18 µm; width = 1.752 ±0.17µm) without acrosomal vesicle, nucleus with highly condensed chromatin forming coarse clots and centriolar complex located in the nuclear fossa; a midpiece (length = 2.561±0.44µm), narrowed rearward, with a cytoplasmic canal; and a flagellum (length = 29.521 ±4.37µm). Fertilization tests with thawed semen demonstrated... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Semen characteristics; Cryopreservation; Brycon cephalus; Ultrastructure; Fish. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000500015 |
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Porto-Foresti,Fábio; Oliveira,Claudio; Maistro,Edson Luis; Foresti,Fausto. |
A study was made of the frequency of B-chromosomes and the population density of Astyanax scabripinnis paranae (Pisces, Characidae, Tetragonopterinae) from three stretches of the Cascatinha stream (Botucatu, SP). In the first stretch the population was estimated to be about 212 individuals and among 35 karyotyped specimens, 23 carried one macro B-chromosome; in the second stretch the population was estimated to be about 650 individuals and among 20 specimens karyotyped, two possessed one macro B-chromosome; in the third stretch the population was estimated to be about 107 individuals and among 10 specimens karyotyped, one carried one macro B-chromosome. A significant difference was observed in the frequency of macro B-chromosomes in females (57%) and males... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84551997000300004 |
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Carvalho,Margarida Lima; Oliveira,Claudio; Foresti,Fausto. |
The present paper reports nuclear DNA content in 30 Neotropical freshwater fish species and summarizes the data on other Neotropical species presented in the literature. Among Neotropical fishes, the nuclear DNA content ranges from 1.04 ± 0.09 pg/nucleus in Corydoras cf. simulatus (2n = 62) to 248.0 pg/nucleus in Lepidosiren paradoxa (2n = 38). A general analysis of the data obtained in the present study for each species showed that DNA measurements were practically constant at the individual level, while significant differences were observed among individuals of the same population. This observation was valid for all species analyzed and was more evident in those species that presented other karyotypic particularities such as sex chromosomes or... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571998000100009 |
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Santos,Lessandra Viviane De Rosa; Foresti,Fausto; Martins,Cesar; Oliveira,Claudio; Wasko,Adriane Pinto. |
Cytogenetic analyses were performed in Cyphocharax modestus, collected at Paranapanema River and Tietê River (São Paulo State, Brazil). A karyotype with 2n = 54 chromosomes was observed in the animals from both Brazilian freshwater river systems. One to four B chromosomes were also detected in individuals from the Paranapanema River, which represents the probable first report of more than a single supernumerary element in a species of the Curimatidae group. C-banding revealed centromeric and telomeric heterochromatin blocks in several chromosomes of the normal karyotype complement of C. modestus. Moreover, while some B chromosomes were characterized by the complete absence of C-bands, others were totally heterochromatic. Although there was a prevalence of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: B chromosomes; C-banding; Curimatidae; Cyphocharax modestus; Supernumerary chromosomes. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200019 |
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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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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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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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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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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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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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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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Registros recuperados: 52 | |
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