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Registros recuperados: 16
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Chromosomal characterization of Amazonian freshwater stingrays with evidence for new karyomorphs and XX/XY sex chromosomes Genet. Mol. Biol.
Valentim,Francisco Carlos de Souza; Porto,Jorge Ivan Rebelo; Feldberg,Eliana.
Abstract Cytogenetic studies in the subfamily Potamotrygoninae have provided valuable insights into the understanding of the evolution and diversification of its species. In the present study, the chromosomal features of seven nominal potamotrygonin species are provided: Plesiotrygon iwamae (2n=74, FN=120), Potamotrygon amazona (2n=66, FN=107), P. constellata (2n=66, FN=110), P. leopoldi (2n=64, FN=102), P. motoro (2n=66, FN=106) from four different localities, and P. orbignyi (2n=66, FN=106), P. scobina (2n=66, FN=104), from Central Amazon. Additionally, we found a new karyomorph in P. wallacei. We considered the localization of Nucleolus Organizer Regions (NORs), as well as the pattern of constitutive heterochromatin, as species-specific characters. We...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Elasmobranchs; Cytogenetics; Chromosomal rearrangements; Sex chromosomes; Karyotypic diversity.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000400578
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Chromosomal variability in the wild ornamental species of Symphysodon (Perciformes: Cichlidae) from Amazon Neotropical Ichthyology
Mesquita,Débora R.; Porto,Jorge I. R.; Feldberg,Eliana.
Cytogenetic studies were conducted on three discus species which inhabit the Amazon in Brazil: Symphysodon haraldi from Manacapuru, S. aequifasciatus from Tefé and S. discus from Barcelos. All individuals showed 2n=60 chromosomes, most of them biarmed. No sexual chromosomal heteromorphism was verified. However, different karyotypic formulae, owing to the presence of subtelocentric chromosomes, were verified for S. aequifasciatus and S. discus. One of the karyotypic formulae from S. aequifasciatus (cytotype 2) differs from the others, due to one of the homologues in the first chromosome pair being significantly larger than the other. A large variability was observed toward the nucleolar organizer regions (NOR) of S. haraldi and S. aequifasciatus. Although...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Discus; Cytogenetics; Polymorphism; Microchromosomes; Multiple NORs.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000200005
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Chromosome mapping of repetitive sequences in four Serrasalmidae species (Characiformes) Genet. Mol. Biol.
Ribeiro,Leila Braga; Matoso,Daniele Aparecida; Feldberg,Eliana.
The Serrasalmidae family is composed of a number of commercially interesting species, mainly in the Amazon region where most of these fishes occur. In the present study, we investigated the genomic organization of the 18S and 5S rDNA and telomeric sequences in mitotic chromosomes of four species from the basal clade of the Serrasalmidae family: Colossoma macropomum, Mylossoma aureum, M. duriventre, and Piaractus mesopotamicus, in order to understand the chromosomal evolution in the family. All the species studied had diploid numbers 2n = 54 and exclusively biarmed chromosomes, but variations of the karyotypic formulas were observed. C-banding resulted in similar patterns among the analyzed species, with heterochromatic blocks mainly present in centromeric...
Tipo: Info:eu-repo/semantics/article Palavras-chave: 5S rDNA; Telomeric sequences; Tambaqui and pacu.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000100009
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Comparative cytogenetics of Carnegiella marthae and Carnegiella strigata (Characiformes, Gasteropelecidae) and description of a ZZ/ZW sex chromosome system Genet. Mol. Biol.
Terencio,Maria Leandra; Schneider,Carlos Henrique; Gross,Maria Claudia; Silva,Adailton Moreira da; Feldberg,Eliana; Porto,Jorge Ivan Rebelo.
Comparative cytogenetic analyses of hatchetfishes Carnegiella marthae and Carnegiella strigata (Gasteropelecidae) from the Rio Negro basin were performed using conventional Giemsa staining, silver (Ag) -staining and C-banding. The diploid chromosome numbers of both species equaled 2n = 50 but their karyotypes were distinct. We found evidence for sex chromosomes in C. marthae since karyotype of males presented 20 M + 12 SM + 4 ST + 14 A and ZZ ST chromosomes while the females presented 20 M + 12 SM + 4 ST + 14 A and ZW ST chromosomes of distinct size. Conversely, C. strigata presented 4 M + 4 SM + 2 ST + 40 A chromosomes without sex chromosome heteromorphism. Karyotypes of both species had two NOR-bearing SM chromosomes of distinct size indicating the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Fish cytogenetics; Karyotype differentiation; NOR phenotypes; Heteromorphic sex chromosome system; Cytotaxonomy.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200011
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Cytogenetic analysis of Baryancistrus xanthellus (Siluriformes: Loricariidae: Ancistrini), an ornamental fish endemic to the Xingu River, Brazil Neotropical Ichthyology
Medeiros,Larissa A.; Ginani,Eduardo G.; Sousa,Leandro M.; Py-Daniel,Lúcia H. Rapp; Feldberg,Eliana.
ABSTRACT Baryancistrus xanthellus is a species from the Ancistrini tribe known commonly as "amarelinho " or "golden nugget pleco". It is one of the most popular and valued ornamental fishes due to its color pattern. Also, it is an endemic species from the Xingu River occurring from Volta Grande do Xingu, region where the Belo Monte Hydropower Dam is being built, to São Félix do Xingu. The current study aimed to cytogenetically characterize B. xanthellus . Results point to the maintenance of 2n=52, which is considered the most common condition for the tribe, and a single nucleolus organizer region (NOR). Mapping of the 18S rDNA confirmed the NOR sites, and the 5S rDNA was mapped in the interstitial position of a single chromosome pair. The 18S and 5S rDNA...
Tipo: Info:eu-repo/semantics/article Palavras-chave: FISH; Habitat endangered; RDNA; Volta Grande do Xingu.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200212
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Cytogenetic studies in fishes of the genera Hassar, Platydoras and Opsodoras (Doradidae, Siluriformes) from Jarí and Xingú Rivers, Brazil Genet. Mol. Biol.
Milhomem,Susana Suely Rodrigues; Souza,Augusto Cesar Paes de; Nascimento,Aline Lira do; Carvalho Jr.,Jaime Ribeiro; Feldberg,Eliana; Pieczarka,Julio Cesar; Nagamachi,Cleusa Yoshiko.
We studied the karyotypes of Hassar cf. orestis and an undescribed Hassar species from the Jarí River and Opsodoras ternetzi, H. orestis and Platydoras cf. costatus from the Xingú River, all with 2n = 58. Constitutive heterochromatin is located in the centromere in most metacentric pairs; in some chromosomes this banding is not present, or it is located on the whole chromosome arm or in the distal regions. The NOR is located on a single biarmed pair at a distal region of the short arm in H. cf. orestis, H. orestis and P. cf. costatus at a distal region of the long arm in O. ternetzi and at a proximal region of the long arm in the Hassar species. In all species (except for Hassar sp.) the CMA3 analysis revealed a rich G-C region coincident with the NOR....
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chromosomes; Amazon; Biodiversity; Siluriformes; Banding; Fluorochromes.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200017
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Cytogenetic studies of two freshwater sciaenids of the genus Plagioscion (Perciformes, Sciaenidae) from the central Amazon Genet. Mol. Biol.
Feldberg,Eliana; Porto,Jorge Ivan Rebelo; Santos,Elen Bethlen Pedraça dos; Valentim,Francisco Carlos Souza.
Cytogenetic characterization of two freshwater sciaenid species from the genus Plagioscion (P. squamosissimus and Plagioscion sp.) was obtained for the first time. Giemsa staining, Ag-NOR and C-banding revealed that both species presented 2n = 48 chromosomes (almost all acrocentric). Single NORs and heterochromatin were found mainly at the pericentromeric position. Karyotypic formulae and NOR location proved to be valuable in showing both interspecific and intraspecific differences. All chromosomes were acrocentric in P. squamosissimus. NORs were located at proximal positions on the long arms of the last chromosome pair of the complement, and were heteromorphic due to size differences. Such heteromorphic NORs seem to be associated with each population...
Tipo: Info:eu-repo/semantics/article
Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300011
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Cytogenetic study of the giant otter Pteronura brasiliensis Zimmermann 1780 (Carnivora, Mustelidae, Lutrinae) Genet. Mol. Biol.
Franco-de-Sá,Jorge Felipe Oliveira; Rosas,Fernando César Weber; Feldberg,Eliana.
The giant otter, Pteronura brasiliensis Zimmermann 1780 (Carnivora, Mustelidae, Lutrinae), was widely distributed in South America but stable populations are now only found in the Pantanal and Amazon regions and the species is classified as endangered. There is only one recognized species of giant otter, although two subspecies of doubtful value have also been cited in the literature. We present the first karyotype of four captive P. brasiliensis specimens, all of which posses 2n = 38 chromosomes as 14M+8SM+6ST+8A and one pair of sexual chromosomes. An heteromorphic secondary constriction, associated with the nucleolar organizer region (NOR), was seen on the long arms of chromosome pair 17. The C-banding technique revealed heterochromatin in the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Amazon; Aquatic mammals; Ariranha; Karyotype.
Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000600011
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Cytogenetic variation of repetitive DNA elements in Hoplias malabaricus (Characiformes - Erythrinidae) from white, black and clear water rivers of the Amazon basin Genet. Mol. Biol.
Santos,Fabíola Araújo dos; Marques,Diego Ferreira; Terencio,Maria Leandra; Feldberg,Eliana; Rodrigues,Luís Reginaldo R..
Abstract Hoplias malabaricus is a common fish species occurring in white, black and clear water rivers of the Amazon basin. Its large distribution across distinct aquatic environments can pose stressful conditions for dispersal and creates possibilities for the emergence of local adaptive profiles. We investigated the chromosomal localization of repetitive DNA markers (constitutive heterochromatin, rDNA and the transposable element REX-3) in populations from the Amazonas river (white water), the Negro river (black water) and the Tapajós river (clear water), in order to address the variation/association of cytogenomic features and environmental conditions. We found a conserved karyotypic macrostructure with a diploid number of 40 chromosomes (20...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Cytogenomics; FISH; RDNA; REX 3; Tapajós river.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572016000100040
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Cytogenetics of two Farlowella species (Loricariidae: Loricariinae): implications on the taxonomic status of the species Neotropical Ichthyology
Marajó,Leandro; Viana,Patrik F.; Ferreira,Milena; Py-Daniel,Lúcia H. Rapp; Feldberg,Eliana.
ABSTRACT Farlowella is one of the most diverse genera of the Loricariinae, restricted to South America rivers. The taxonomic and phylogenetic relationships among its species are contentious and, while genetic studies would contribute to the understanding of their relationships, the only available datum refer to the karyotype description of only one species. In the present study two Amazonian species, Farlowella cf. amazonum and F. schreitmuelleri, were analyzed using conventional and molecular cytogenetic procedures. Both species had diploid chromosome number 58, but different fundamental numbers (NF) 116 and 112, respectively, indicative of chromosomal rearrangements. C-banding is almost poor, especially in F. cf. amazonum, and occurs predominantly in the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Amazon region; Chromosomal markers; Karyotypic characterization; Ribosomal DNA; Twig catfish.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252018000400213
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Cytotaxonomy and karyoevolution of the genus Crenicichla (Perciformes, Cichlidae) Genet. Mol. Biol.
Benzaquem,Denise Corrêa; Feldberg,Eliana; Porto,Jorge Ivan Rebelo; Gross,Maria Claudia; Zuanon,Jansen Alfredo Sampaio.
Karyotypes of six cichlid species of the genus Crenicichla were investigated. The species C. cincta, C. inpa, C. reticulata, C. lugubris, and C. cf. johanna were collected from Amazon basin, and C. britskii was collected from the Paraná-Paraguai basin. All of the analysed species showed 2n = 48 chromosomes; however, C. cincta, C. lugubris, C. cf. johanna, and C. britskii had a karyotype formula of 8M-SM+40ST-A, FN = 56, while C. inpa and C. reticulata exhibited the formula 6M-SM+42ST-A, FN = 54. Analysis of active Ag-NORs revealed two NOR-bearing chromosomes in all species; however, theses cistrons were located on different chromosome pairs and/or in different chromosome locations in each species. This condition bears evolutionary significance, since it is...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Karyotype; Pike cichlid; Chromosome marker; Amazon.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200016
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Esterase-D and chromosome patterns in Central Amazon piranha (Serrasalmus rhombeus Linnaeus, 1766) from Lake Catalão Genet. Mol. Biol.
Teixeira,Aylton Saturnino; Nakayama,Celeste Mutuko; Porto,Jorge Ivan Rebelo; Feldberg,Eliana.
This study presents additional genetic data on piranha (Serrasalmus rhombeus Linnaeus, 1766) complex previously diagnosed due to the presence of distinct cytotypes 2n = 58 and 2n = 60. Three esterase-D enzyme loci (Est-D1, Est-D2 and Est-D3) were examined and complemented with chromosomal data from 66 piranha specimens collected from Lake Catalão. For all specimens the Est-D1 and Est-D2 loci were monomorphic. In contrast, the Est-D3 locus was polymorphic with genotypes and alleles being differentially distributed in the previously described cytotypes and served as the basis for detecting a new cytotype (2n = 60 B). In cytotype 2n = 58 the Est-D3 locus was also polymorphic and presented Mendelian allelic segregation with four genotypes (Est-D3(11),...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Brazilian Amazon basin; Esterase enzymes; Serrasalmus rhombeus species complex; Karyotype.
Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000300018
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Karyological analysis of Proechimys cuvieri and Proechimys guyannensis (Rodentia, Echimyidae) from central Amazon Genet. Mol. Biol.
Silva,Carlos Eduardo Faresin e; Eler,Eduardo Schmidt; Silva,Maria Nazareth F. da; Feldberg,Eliana.
The aim was to characterize the karyotype of rodents of the genus Proechimys from three localities in the central Brazilian Amazon, in the search for new markers that might shed light on our understanding of the taxonomy and evolutionary history of this taxon. Two karyotypes were found, viz., 2n = 28, FN = 46 in individuals from the NRSP (Cuieiras River) and REMAN (Manaus), and 2n = 46, FN = 50 in individuals from the Balbina Hydroelectric Plant. While individuals with the karyotype with 2n = 28 chromosomes were morphologically associated with Proechimys cuvieri, their karyotype shared similarities with those of the same diploid number in two other regions. Although three karyotypes are described for Proechimys cuvieri, no geographic distribution pattern...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Spiny rats; C-banding; Amazon region; Karyotypes; FISH.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100012
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Karyotype characterization and ZZ/ZW sex chromosome heteromorphism in two species of the catfish genus Ancistrus Kner, 1854 (Siluriformes: Loricariidae) from the Amazon basin Neotropical Ichthyology
Oliveira,Renildo R. de; Feldberg,Eliana; Anjos,Maeda B. dos; Zuanon,Jansen.
We present karyotypic characteristics and report on the occurrence of ZZ/ZW sex chromosomes in Ancistrus ranunculus (rio Xingu) and Ancistrus sp. "Piagaçu" (rio Purus), of the Brazilian Amazon. Ancistrus ranunculus has a modal number of 2n=48 chromosomes, a fundamental number (FN) of 82 for both sexes, and the karyotypic formula was 20m+8sm+6st+14a for males and 19m+9sm+6st+14a for females. Ancistrus sp. "Piagaçu" presented 2n=52 chromosomes, FN= 78 for males and FN= 79 for females. The karyotypic formula was 16m+8sm+2st+26a for males and 16m+9sm+2st+25a for females. The high number of acrocentric chromosomes in karyotype of Ancistrus sp. "Piagaçu" differs from the majority of Ancistrini genera studied so far, and may have resulted from pericentric...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Hypostominae; Ancistrini; Cytogenetics; Evolution; Heterochromatin.
Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000300010
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Karyotype differentiation and cytotaxonomic considerations in species of Serrasalmidae (Characiformes) from the Amazon basin Neotropical Ichthyology
Nakayama,Celeste Mutuko; Feldberg,Eliana; Bertollo,Luiz Antonio Carlos.
Six species of Serrasalmidae from the central Amazon, representatives of the genera Serrasalmus (S. elongatus, S. maculatus, S. cf. rhombeus, and S. rhombeus), Pygocentrus (P. nattereri), and Colossoma (C. macropomum), were analyzed regarding the distribution of the Ag-NORs, C-positive heterochromatin and 18S and 5S rRNA genes on the chromosomes. All specimens had 2n = 60 chromosomes, except S. cf. rhombeus, with 2n = 58, and C. macropomum with 2n = 54 chromosomes. The Ag-NORs were multiple and located on the short arms of subtelo-acrocentric chromosomes in all Serrasalmus species and in P. nattereri, but were found on metacentric chromosomes in C. macropomum. The 18S rDNA sites were usually coincident with Ag-NORs, although some species had a higher...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chromosomal evolution; Fish; Heterochromatin; Piranhas; Ribosomal genes.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000100005
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Mapping of ribosomal genes and chromosomal markers in three species of the genus Serrasalmus (Characidae, Serrasalminae) from the Amazon basin Genet. Mol. Biol.
Nakayama,Celeste M.; Feldberg,Eliana; Bertollo,Luiz Antonio C..
Karyotypic characteristics of three species of the genus serrasalmus ( S. altispinnis , S. gouldingi and S. Serrulatus ) from the middle and lower Negro River, Amazon Basin, were investigated using different staining techniques and Fluorescent in situ hybridization with 5S and 18S rDNA probes. The diploid number was invariably 2n = 60 and the fundamental number was FN = 110. Nevertheless, the karyotypes differed from each other in composition: 24m, 20sm, 6st, 10a in S. altispinnis ; 22m, 22sm, 6st, 10a in S. gouldingi and 20m, 22sm, 8st, 10a in S. serrulatus. The karyotype of S. altispinnis differed from the one previously described in a population from the Pitinga River. C-positive constitutive heterochromatin was mainly pericentromeric in...
Palavras-chave: Chromosome banding; Cytotaxonomy of piranhas; FISH; Karyotype; Ribosomal DNA.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000500011
Registros recuperados: 16
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