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| Registros recuperados: 17 | |
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| Margarido,Vladimir Pavan; Galetti Junior,Pedro Manoel. |
| This is the first description of the karyotype of Leporinus desmotes. The diploid female number was 2n = 54 meta- and submetacentric chromosomes. The nucleolar organizing regions (NORs) were studied by silver nitrate staining and rDNA fluorescence in situ hybridization (FISH) and were found to be located in the telomeric region of the long arm of the 9th pair. C-banding revealed centromeric and telomeric heterochromatin segments in most chromosomes. Intercalar blocks of heterochromatin were observed in the long arm of six chromosome pairs. Besides a NOR-adjacent heterochromatin, all of the intercalar heterochromatic segments were brightly fluorescent by mithramycin staining. These data suggest that a unique amplification of a primordial GC-rich... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000300012 |
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| Konerat,Jocicléia Thums; Bueno,Vanessa; Baumgartner,Lucas; Martins-Santos,Isabel Cristina; Margarido,Vladimir Pavan. |
| B chromosomes are extra chromosomes from the normal chromosomal set, found in different organisms, highlighting their presence on the group of fishes. Callichthys callichthys from the upper Paraná River has a diploid number of 56 chromosomes (26 m-sm + 30 st-a) for both sexes, with the presence of a sporadically acrocentric B chromosome. Moreover, one individual presented a diploid number of 57 chromosomes, with the presence of a morphologically ill-defined acrocentric B chromosome in all analyzed cells. The physical mapping of 5S and 18S rDNA shows multiple 5S rDNA sites and only one pair of chromosomes with 18S sites in C. callichthys, except for two individuals. These two individuals presented a third chromosome bearing NORs (Ag-staining and 18S rDNA)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 18S rDNA; 5S rDNA; Chromosomal rearrangements; FISH; Supernumerary chromosome. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000300603 |
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| Kowalski,Samantha; Paiz,Leonardo Marcel; da Silva,Maelin; Machado,Amanda de Souza; Feldberg,Eliana; Traldi,Josiane Baccarin; Margarido,Vladimir Pavan; Lui,Roberto Laridondo. |
| ABSTRACT Historically, there are divergences in the species allocation between Centromochlus and Tatia. This study aimed to generate the first cytogenetic data about Centromochlus and, by analyzing a population of Centromochlus heckelii from the Amazon River basin, to contribute as evidence to a historical taxonomic dilemma. Diploid number of 46 chromosomes and a heteromorphic pair was found in the female karyotypes, thus characterizing a ZZ/ZW sex chromosome system. Pale blocks of heterochromatin were located in centromeric regions of some chromosomes; however, the exclusive female chromosome (W) is almost entirely heterochromatic. AgNORs were detected in terminal position on the short arms of one acrocentric pair in males and two chromosome pairs in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Centromochlinae; Cytogenetics; Sex chromosome system; Taxonomy; ZZ/ZW. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000300203 |
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| Santos,Dayane Petik dos; Felicetti,Denise; Baumgärtner,Lucas; Margarido,Vladimir Pavan; Blanco,Daniel Rodrigues; Moreira-Filho,Orlando; Lui,Roberto Laridondo. |
| ABSTRACT Auchenipteridae is divided into subfamilies Centromochlinae and Auchenipterinae. Parauchenipterus is included in the latter and is subject of taxonomic discussions concerning its validation or synonymization with Trachelyopterus. Herein, three species from two hydrographic basins were cytogenetically analyzed: Parauchenipterus striatulus from Doce River and two sympatric species, P. galeatus and Trachelyopterus coriaceus, from the Araguaia River. Diploid number of 58 chromosomes was verified for all species, but P. striatulus has different karyotype formula from the others. The three species have heterochromatin located in terminal regions of almost all chromosomes and in pericentromeric region on acrocentric chromosomes. Simple NORs was verified... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cryptic species; FISH; Parauchenipterus; Problematic taxonomy; 5S rDNA. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252021000100214 |
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| Marques,Marilza Barbosa de Almeida; Moreira-Filho,Orlando; Garcia,Caroline; Margarido,Vladimir Pavan. |
| Two Siluriformes species endemic to the São Francisco River basin were characterized by conventional and differential cytogenetic analyses involving C-banding, Ag-nucleolar organizer region (NOR) and chromomycin A3 (CMA3) staining, and FISH (fluorescent in situ hybridization) with 18S and 5S rDNA probes. Conorhynchus conirostris presents a higher diploid number (2n = 60) than those detected in Pimelodidae representatives, whereas Lophiosilurus alexandri, with a karyotype of 2n = 54 chromosomes, presents a chromosomal constitution similar to that found in the family Pseudopimelodidae. Plesiomorphic characteristics such as single NORs at terminal positions are found in both species, as revealed by CMA3 and silver nitrate staining, and FISH with a 18S rDNA... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Incertae sedis; Pimelodidae; Pseudopimelodidae; RDNA; Siluriformes. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200008 |
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| Prestes,Anahiê Bortoncello; Nardelli,Aline; Paiz,Leonardo Marcel; Gavazzoni,Mariane; Margarido,Vladimir Pavan. |
| ABSTRACT Bryconamericus is a highly diverse group of characid fishes, being cytogenetic a valuable tool for the delimitation of species. Bryconamericus aff. iheringii (Upper Uruguay/Lower Paraná), B. coeruleus (Upper Paraná), B. cf. ecai e B. cf. eigenmanni (Upper Uruguay) were studied cytogenetically, and presented 2n=52 chromosomes, with interpopulational/interspecific variation of karyotype and fundamental number. Heterochromatin was evidenced in pericentromeric, telomeric and interstitial regions, and it was shown to be an important cytogenetic marker. Single nucleolar organizing regions (NORs) were found in B. cf. eigenmanni, B. cf. ecai and B. aff. iheringii (Lower Paraná), and multiple in B. aff. iheringii (Upper Uruguay) and B. coeruleus, with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome rearrangements; Co-localization; Cytotaxonomy; Cytosystematics; Intra and interspecific variation; Ribosomal genes. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000300203 |
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| Vicari,Marcelo Ricardo; Pazza,Rubens; Artoni,Roberto Ferreira; Margarido,Vladimir Pavan; Bertollo,Luiz Antonio Carlos. |
| Hoplias malabaricus (trahyra) is a widespread fish species over the Neotropical region with diversified inter-populational karyotypes (cytotypes), which may correspond to a species complex. Despite the wide distribution in the South American basins, some authors have questioned its natural origin in the Iguaçu river, an important Brazilian river basin which is characterized by several endemic fish species. We have analyzed the karyotype of H. malabaricus from different collection sites of this river, by conventional and banding methods. Our results, in addition to our previous data concerning geographic distribution of the cytotypes, contribute to better understand the origin of H. malabaricus on the Iguaçu river, reinforcing the proposition that it is a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome evolution; Karyotypes distribution; Endemism. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000300015 |
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| Fernandes,Carlos Alexandre; Aguiar,Allan Kardec Moreira de; Paiz,Leonardo Marcel; Baumgärtner,Lucas; Piscor,Diovani; Margarido,Vladimir Pavan. |
| ABSTRACT Gymnorhamphichthys britskii is a Neotropical electric fish of family Rhamphichthyidae described from the Paraná-Paraguay system. This study reports the first karyotypic description of G. britskii collected from the upper Paraná river basin, which presented 2n=38 chromosomes, karyotype composed of 14 metacentric, 8 submetacentric, 2 subtelocentric and 14 acrocentric chromosomes, and fundamental number as 62 for both sexes. Heteromorphic sex chromosomes were absent. A single pair of nucleolar organizing regions (NORs) was detected in the submetacentric chromosome pair number 9 by silver staining and confirmed by the 18S rDNA probe. The 5S rDNA was located in a single chromosome pair. Heterochromatic regions were clearly observed in the short arms of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ag-NORs; C-banding; Fish cytogenetics; Karyotype evolution; Repetitive sequences. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000300205 |
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| Lui,Roberto Laridondo; Blanco,Daniel Rodrigues; Martinez,Juliana de Fátima; Margarido,Vladimir Pavan; Venere,Paulo Cesar; Moreira Filho,Orlando. |
| Ageneiosus is the most widely distributed genus of the family Auchenipteridae among South American river basins. Although chromosome studies in the family are scarce, this genus has the largest number of analyzed species, with 2n = 54 to 56 chromosomes, differing from the rest of the family (2n = 58). This study aimed to analyze Ageneiosus inermis from the Araguaia River basin. The diploid number found was of 56 chromosomes. Heterochromatin was allocated in terminal region of most chromosomes, plus a pericentromeric heterochromatic block in pair 1, a pair distinguished by size in relation to other chromosomes pairs. AgNORs were detected in only one submetacentric chromosome pair, which was confirmed by FISH. 5S rDNA was present in only one metacentric... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: C banding; Cytogenetic Markers; [GATA]n sequence; RDNA-FISH; [TTAGGG]n sequence. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200327 |
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| Cavalli,Daiane; Frota,Augusto; Lira,Angelica Dorigon; Gubiani,Éder André; Margarido,Vladimir Pavan; Graça,Weferson Júnio da. |
| Abstract: Knowledge of the fish species in river basins is among the minimum requirements for the management of water and fish resources. Therefore, the aim of this study was to update the fish species composition of the Piquiri River basin, upper Paraná River basin. Data were gathered from recent information published in specialized literature and records for ichthyology collections. This update reports the occurrence of 152 fish species distributed in 8 orders, 31 families, and 89 genera. Non-native species accounted for 20% of all species, and the construction of the Itaipu Power Plant and its fish ladder were the main vectors of introduction. Three percent of the species were endangered, and 11% were classified as migratory. The Piquiri River basin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ichthyofaunal survey; Species knowledge; Preservation; Upper Paraná River basin. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032018000200305 |
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| Registros recuperados: 17 | |
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