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	Provedor de dados Rev. Econ. Sociol. Rural (1) Autor Conterato,Marcelo Antonio (1) Escher,Fabiano (1) Scarton,Luciana Maria (1) Schneider,Sergio (1) Palavra-chave Agricultura familiar (1) Agricultura não familiar (1) Censo Agropecuário 2006 (1) Pluriatividade (1) Plurirrendimentos (1) Tipo do documento Info:eu-repo/semantics/article (1) Ano 2014 (1) País Brazil (1) Idioma Português (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 52 Primeira ... 1 2 3 ... Última Discrimination of Shark species by simple PCR of 5S rDNA repeats Genet. Mol. Biol. 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 Editorial Genet. Mol. Biol. Foresti,Fausto; Galetti Junior,Pedro Manoel. Tipo: Info:eu-repo/semantics/other Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200001 Estimated frequency of B-chromosomes and population density of Astyanax scabripinnis paranae in a small stream Braz. J. Genet. 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 Ano: 1997 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84551997000300004 First report of a B chromosome in a natural population of Astyanax altiparanae (Characiformes, Characidae) Genet. Mol. Biol. 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 Genetic variability of two populations of Pseudoplatystoma reticulatum from the Upper Paraguay River Basin Genet. Mol. Biol. 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 Identification and description of distinct B chromosomes in Cyphocharax modestus (Characiformes, Curimatidae) Genet. Mol. Biol. 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 Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus) and other eukaryote species revealed by nucleotide and amino acid sequence analyses Genet. Mol. Biol. Poletto,Andréia B.; Wasko,Adriane P.; Oliveira,Claudio; Azevedo,Alexandre; Carvalho,Robson F.; Silva,Maeli Dal Pai; Foresti,Fausto; Martins,Cesar. Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus) were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa) sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The... Tipo: Info:eu-repo/semantics/article Palavras-chave: Actin; Expression pattern; Nile tilapia; Oreochromis niloticus. Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200031 Interspecific chromosomal divergences in the genus Characidium (Teleostei: Characiformes: Crenuchidae) Neotropical Ichthyology Alves,José Carlos Pansonato; Paiva,Luiz Ricardo de Souza; Oliveira,Claudio; Foresti,Fausto. Karyotypes of seven fish species of the genus Characidium, three of them studied for the first time, were characterized using conventional cytogenetic techniques (Giemsa staining, Ag-NOR, and C-banding). All species presented a diploid number of 2n=50, with only metacentric and submetacentric chromosomes, as observed in all Characidium species studied. In two species cells with one to three B chromosomes were observed. All species analyzed have a single NOR-bearing chromosome pair with morphological differences among them. Characidium cf. zebra shows heterochromatic blocks restricted to the pericentromeric regions of all chromosomes denoting the absence of a sex chromosome system. On the other hand, the species Characidium lanei, C. pterostictum, C.... Tipo: Info:eu-repo/semantics/article Palavras-chave: Karyotypic evolution; Sex chromosomes; B-chromosomes; Ag-NORs. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000100010 Intraspecific crosses resulting in the first occurrence of eight and nine B chromosomes in Prochilodus lineatus (Characiformes, Prochilodontidae) Genet. Mol. Biol. Voltolin,Tatiana Aparecida; Senhorini,José Augusto; Foresti,Fausto; Bortolozzi,Jehud; Porto-Foresti,Fábio. B chromosomes are supernumerary elements present in about 15% of eukaryotic species and are most frequently heterochromatic, behave parasitically, show a transmission rate higher than standard (A) chromosomes, and can provoke harmful effects on carriers. In the current work, Prochilodus lineatus individuals carrying eight and nine B chromosomes were obtained by induced crossing performed involving breeders with different B chromosome numbers in their cells. The high B chromosome numbers found in the offspring were recorded for the first time in this species. The use of cytogenetic techniques applied in the present study revealed that regardless of the increase in number of B chromosomes in the genome of these individuals, those elements did not presented... Tipo: Info:eu-repo/semantics/article Palavras-chave: Supernumerary chromosome; Heterochromatic chromosome; Cross-fertilization. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200009 Karyological characterization of four Neotropical fish species of the genus Hisonotus (Teleostei, Loricariidae, Hypoptopomatinae) from distinct Brazilian river basins Genet. Mol. Biol. Andreata,Artur Antonio; Oliveira,Claudio; Foresti,Fausto. The karyotypes of four Hisonotus species (two provisionally-named species A and D, H. nigricauda, and H. leucofrenatus) were found to have the same diploid number of 2n = 54 and interstitial silver-staining nucleolus organizer regions (Ag-NORs) located on the long arm of the largest metacentric pair. The C-banding pattern appeared to be species-specific, with one group (H. nigricauda and the unnamed species A and D) being characterized by small amounts of positive C-banded segments and containing a sub-group (species A and D) identified by a large positive C-banded segment on a small metacentric chromosome pair. The second group contained different samples of H. leucofrenatus, characterized by a larger amount of C-band positive segments spread over several... Tipo: Info:eu-repo/semantics/article Palavras-chave: Fish cytogenetics; Karyotypes; Ag-NORs; C-band; Chromosome evolution. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000100013 Karyotype description and evidence of multiple sex chromosome system X1X1X2X2/X1X2Y in Potamotrygon aff. motoro and P. falkneri (Chondrichthyes: Potamotrygonidae) in the upper Paraná River basin, Brazil Neotropical Ichthyology Cruz,Vanessa Paes da; Shimabukuro-Dias,Cristiane Kioko; Oliveira,Claudio; Foresti,Fausto. Cytogenetic analysis of Potamotrygon aff. motoro and P. falkneri indicated the occurrence of an X1X1X2X2/X1X2 Y multiple sex chromosome system in both species, with 2n = 66 chromosomes for females and 2n = 65 chromosomes for males. The nucleolus organizer regions (NORs) identified using Ag-NOR technique showed that both species have multiple Ag-NORs (5 to 7 chromosomes stained). C-banding technique indicated the presence of heterochromatic blocks in the centromeric regions of almost all chromosomes in both species. Through this study there was evidence of heterogeneity in the karyotypes, which suggests that chromosomal rearrangements such as inversions and/or translocations occurred during the chromosomal evolution in two species of this genus. Tipo: Info:eu-repo/semantics/article Palavras-chave: Cytogenetic; NOR; C-band; Fish; Stingrays. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000100020 Karyotype description of five species of Trichomycterus (Teleostei: Siluriformes: Trichomycteridae) Genet. Mol. Biol. Sato,Luciana Ramos; Oliveira,Claudio; Foresti,Fausto. Trichomycteridae is a family of small catfish which are widely distributed throughout Southern Central America and South America. The present study showed that the cis-Andean species Trichomycterus florensis, Trichomycterus sp. aff. Trichomycterus itatiyae, Trichomycterus reinhardti, Trichomycterus davisi and Trichomycterus auroguttatus had 2n = 54 chromosomes (42 metacentric, 10 submetacentric and 2 subtelocentric), with T. reinhardti, T. auroguttatus and T. sp. aff. T. itatiyae exhibiting only one chromosome pair with silver-stained nucleolus organizer regions (NORs). The cytogenetic data suggest the existence of at least two groups of species in the cis-Andean representatives of the genus Trichomycterus. In the first group the first metacentric pair is... Tipo: Info:eu-repo/semantics/article Palavras-chave: Chromosome evolution; NOR banding; Fish. Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000100008 Karyotypic conservatism in five species of Prochilodus (Characiformes, Prochilodontidae) disclosed by cytogenetic markers Genet. Mol. Biol. Voltolin,Tatiana Aparecida; Penitente,Manolo; Mendonça,Bruna Bueno; Senhorini,José Augusto; Foresti,Fausto; Porto-Foresti,Fábio. The family Prochilodontidae is considered a group with well conserved chromosomes characterized by their number, morphology and banding patterns. Thence, our study aimed at accomplishing a cytogenetic analysis with conventional methods (Giemsa staining, silver staining of the nucleolus organizer regions-AgNOR, and C-banding) and fluorescence in situ hybridization (FISH) with 18S and 5S ribosomal DNA probes in five species of the Prochilodus genus (Prochilodus argenteus, Prochilodus brevis, Prochilodus costatus, Prochilodus lineatus and Prochilodus nigricans) collected from different Brazilian hydrographic basins. The results revealed conservatism in chromosome number, morphology, AgNORs 18S and 5S rDNAs location and constitutive heterochromatin... Tipo: Info:eu-repo/semantics/article Palavras-chave: AgNOR; C-banding; Hydrographic basins; Conserved karyotype; FISH. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000300008 Karyotypic conservatism in samples of Characidium cf. zebra (Teleostei, Characiformes, Crenuchidae): physical mapping of ribosomal genes and natural triploidy Genet. Mol. Biol. Pansonato-Alves,José Carlos; Oliveira,Claudio; Foresti,Fausto. Basic and molecular cytogenetic analyses were performed in specimens of Characidium cf. zebra from five collection sites located throughout the Tietê, Paranapanema and Paraguay river basins. The diploid number in specimens from all samples was 2n = 50 with a karyotype composed of 32 metacentric and 18 submetacentric chromosomes in both males and females. Constitutive heterochromatin was present at the centromeric regions of all chromosomes and pair 23, had additional interstitial heterochromatic blocks on its long arms. The nucleolar organizer regions (NORs) were located on the long arms of pair 23, while the 5S rDNA sites were detected in different chromosomes among the studied samples. One specimen from the Alambari river was a natural triploid and had... Tipo: Info:eu-repo/semantics/article Palavras-chave: Characidium; Heterochromatin; 18S rDNA; 5S rDNA; Natural triploidy. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200007 Microstructural chromosome reorganization in the genus Trichomycterus (Siluriformes: Trichomycteridae) Neotropical Ichthyology Oliveira,Maria Lígia M. de; Utsunomia,Ricardo; Pansonato-Alves,José Carlos; Scacchetti,Priscilla C.; Primo,Cleberson C.; Vicari,Marcelo R.; Artoni,Roberto F.; Centofante,Liano; Moreira-Filho,Orlando; Oliveira,Claudio; Foresti,Fausto. Trichomycterus is a specious fish genus within Trichomycterinae and displays remarkable karyotype diversity. However, knowledge about their genomic structure and location of repetitive sequence is still limited. In order to better understand the karyotype diversification, we analyzed nine species of Trichomycterus using classical and molecular cytogenetic techniques. Results revealed a conserved diploid chromosome number of 2n=54 chromosomes in all analyzed species, although remarkable differences on the constitutive heterochromatin distribution were observed. In addition, while the 18S rDNA showed a conserved distribution pattern, the 5S rDNA sites showed a quite diverse location considering the analyzed species. Remarkably, both ribosomal genes were... Tipo: Info:eu-repo/semantics/article Palavras-chave: Karyotype diversity; Repetitive DNA; RDNA; Supernumerary chromosomes. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200211 Mitochondrial DNA variation in wild populations of Leporinus elongatus from the Paraná River basin Genet. Mol. Biol. Martins,Cesar; Wasko,Adriane P.; Oliveira,Claudio; Foresti,Fausto. Leporinus elongatus, a fish species widely distributed throughout the Paraná River basin in South America, is an important fishery resource and a valuable species in aquaculture programs. Despite its great economic importance, several wild populations have been suffering a drastic reduction. The comprehension of its population structure represents an important step for the conservation of these organisms in natural environments, and also for the selection of wild stocks to be used in hatchery programs. In order to understand the genetic-population structure of L. elongatus, D-loop mitochondrial DNA analyses were applied in six wild populations of the species. The results were used to estimate the levels of within and among population genetic variability.... Tipo: Info:eu-repo/semantics/article Palavras-chave: Conservation genetics; D-loop; Genetic variability; Leporinus elongatus; MtDNA. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000100006 Molecular and cytogenetic analyses of cryptic species within the Synbranchus marmoratus Bloch, 1795 (Synbranchiformes: Synbranchidae) grouping: species delimitations, karyotypic evolution and intraspecific diversification Neotropical Ichthyology 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 Molecular and morphological approaches for species delimitation and hybridization investigations of two Cichla species Iheringia, Sér. Zool. Mourão,Andrea A. F.; Freitas-Souza,Diogo; Hashimoto,Diogo T.; Ferreira,Daniela C.; Prado,Fernanda D. do; Silveira,Rosicleire V.; Foresti,Fausto; Porto-Foresti,Fábio. ABSTRACT The hybridization is a widely-discussed issue in several studies with fish species. For some authors, hybridization may be related with diversification and speciation of several groups, or also with the extinction of populations or species. Difficulties to differentiate species and hybrids may be a problem to correctly apply a management of wild species, because hybrid lineages, especially the advanced ones, may resemble the parental species. The genus Cichla Bloch & Schneider, 1801 constitutes an interesting experimental model, considering that hybridization and taxonomic uncertainties hinder a correct identification. Considering these problems, in this study, we developed genetic methodologies and applied meristic and morphometric approaches... Tipo: Info:eu-repo/semantics/article Palavras-chave: Cichla kelberi; Cichla piquiti; Carijó; Cluster Similarity; PCA; PCR-multiplex. Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212017000100216 Molecular identification of intergenus crosses involving catfish hybrids: risks for aquaculture production Neotropical Ichthyology Hashimoto,Diogo T.; Prado,Fernanda D.; Foresti,Fausto; Porto-Foresti,Fábio. ABSTRACT Monitoring of the interspecific hybrid production and trade is essential for the appropriate management of these animals in fish farms. The identification of catfish hybrids by morphological analysis is unreliable, particularly of juveniles and post-F1 individuals. Therefore, in the present study, we used five molecular markers (four nuclear genes and one mitochondrial gene) to detect hybrids in the trade of pimelodid juvenile fish from different stocks purchased of five seed producers in Brazil. Samples commercialized as pintado (pure species Pseudoplatystoma corruscans ) from three fish farms were genetically identified as hybrid cachapinta (♀ P. reticulatum x ♂ P. corruscans ). In the stocks purchased as cachandiá (hybrid between ♀ P.... Tipo: Info:eu-repo/semantics/article Palavras-chave: Fish farm; Hybridization; Molecular markers; Nuclear genes; Pimelodidae. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200213 Nuclear DNA content determination in Characiformes fish (Teleostei, Ostariophysi) from the Neotropical region Genet. Mol. Biol. Carvalho,Margarida Lima; Oliveira,Claudio; Navarrete,Maria Clara; Froehlich,Otávio; Foresti,Fausto. In the present study, nuclear DNA content was analyzed in 53 species of Characiformes fish from the Neotropical region. Diploid number ranged from 2n = 48 in Astyanax fasciatus, Gymnocorymbus ternetzi and Hyphessobrycon griemi to 2n = 102 in Potamorhina squamoralevis, with a modal number of 54 chromosomes. Nuclear DNA content ranged from 1.70 ± 0.04 pg of DNA per diploid nucleus in Acestrorhynchus pantaneiro to 3.94 ± 0.09 pg in Tetragonopterus chalceus. A general analysis showed a mean value of 2.9 pg of DNA per diploid nucleus. Very similar DNA content values were observed in the species of the family Cynodontidae which showed a variation of 3% between the two genera studied. Small variations were observed between populations of Gymnocorymbus ternetzi,... Tipo: Info:eu-repo/semantics/article Palavras-chave: Nuclear DNA; DNA content; Chromosome; Fish; Evolution. Ano: 2002 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000100010 Registros recuperados: 52 Primeira ... 1 2 3 ... Última

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