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| Registros recuperados: 16 | |
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| 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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| FALCIONE,CAMILA; HERNANDO,ALEJANDRA; BRESSA,MARÍA JOSÉ. |
| ABSTRACT We described the karyotypes of five snake taxa from Argentina: Erythrolamprus almadensis, E. ceii, E. poecilogyrus caesius, E. p. schotti and E. p. sublineatus, and also intergrading individuals between the last two subspecies by conventional staining, chromosome bandings and fluorescent in situ hybridization (FISH) with 28S ribosomal DNA probes. Erythrolamprus ceii and E. almadensis share a diploid chromosome number of 2n= 28, whereas in E. poecilogyrus intraspecific variations were observed: E. p. caesius has 2n= 28, E. p. schotti and E. p. sublineatus as well as in the intergrading individuals have 2n= 32. In E. almadensis and E. p. caesius, the 2nd and 6th chromosome pairs respectively are heteromorphic by size, morphology and C-banding... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ag-NOR; C-banding; Xenodontini; Fluorescent banding; RDNA-FISH; Sex chromosomes. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000401417 |
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| Mendes-Neto,Ernani de Oliveira; Vicari,Marcelo Ricardo; Campaner,Carlos; Nogaroto,Viviane; Artoni,Roberto Ferreira; Almeida,Mara Cristina. |
| Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sex chromosomes; Meiosis; Metaphase; FISH; 18S rDNA. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200007 |
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| Santos,Emanoel Oliveira dos; Deon,Geize Aparecida; Almeida,Rafael Bonfim de; Oliveira,Ezequiel Aguiar de; Nogaroto,Viviane; Silva,Hugmar Pains da; Pavanelli,Carla Simone; Cestari,Marta Margarete; Bertollo,Luiz Antonio Carlos; Moreira-Filho,Orlando; Vicari,Marcelo Ricardo. |
| Abstract Parodontidae is a small group of fish and some species are particularly difficult to identify due to the lack of sufficiently consistent morphological traits. Cytogenetically, the species possess 2n = 54 chromosomes and are either sex-homomorphic or sex-heteromorphic (regarding its chromosomes). We evaluated data on color, tooth morphology, cytogenetics, and mitochondrial markers (COI) in Apareiodon specimens from the Aripuanã River (Amazon basin) and the results were compared to other congeneric taxa. Morphological results show an overlap of body color and tooth morphology to other known Apareiodon. The cytogenetics data showed that the 2n = 54 chromosomes, 50 m/sm + 4 st and, a ZZ/ZW sex chromosome system in Apareiodon sp. are common to other... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomal differentiation; Hidden diversity; Repetitive DNA; Sex chromosomes. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000300365 |
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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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| Nirchio,Mauro; Oliveira,Claudio; Ferreira,Irani Alves; Granado,Angel; Ron,Ernesto. |
| The karyotype and chromosomal characteristics of the characid fish Triportheus venezuelensis were investigated using differential staining techniques (C-banding, Ag-NOR staining) and fluorescent in situ hybridization (FISH) with an 18S rDNA probe. The diploid chromosome number (2n = 52), karyotype composition and sex chromosome determination system of the ZZ/ZW type were the same as previously described in other species of the genus Triportheus. However, extensive variation regarding nucleolus organizer regions (NOR) different from other species was observed. 18S rDNA sequences were distributed on nine chromosome pairs, but the number of chromosomes with Ag-NORs was usually lower, reaching a maximum of four chromosomes. When sequential staining experiments... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 18S rDNA; Ag-NORs; C-band; FISH; Fish cytogenetics; Sex chromosomes. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100007 |
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| 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 |
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| Selivon,Denise; Perondini,André L.P.; Rocha,Lincoln S.. |
| The study comprises the description of the C-banded mitotic chromosomes of five species of Anastrepha, A. amita Zucchi, A. turpiniae Stone, A. zenildae Zucchi, A. grandis (Macquart) and A. leptozona Hendel , and a reanalysis of the chromosomes of three other species, A. distincta Greene, A. obliqua (Macquart) and A. sororcula Zucchi. The species have a diploid number of 12, while A. leptozona has 2n = 10. Heteromorphism of the sex chromosomes is present in all of the species, which have a XY/XX sex chromosome system. A. grandis and A. leptozona have meta and submetacentric autosomes while all of the chromosomes in the other species are acrocentric. The species can be characterized unequivocally by the length and the pattern of blocks of heterochromatin in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heterochromatin; Mitotic chromosomes; Sex chromosomes; C-band. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2005000200015 |
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| Silva,Danillo S.; Peixoto,Luiz A. W.; Pieczarka,Julio C.; Wosiacki,Wolmar B.; Ready,Jonathan S.; Nagamachi,Cleusa Y.. |
| Eigenmannia species are widely distributed in the Neotropics, with eight valid species currently recognized. Populations of Eigenmannia from three locations in the eastern Amazon were investigated using cytogenetic and morphological techniques, revealing two taxa designated here as Eigenmannia sp. "A" and Eigenmannia sp. "B". The species differ in three morphometric characters, two meristic characters, and one osteological character. Eigenmannia sp. "A" presents 2n = 34 (22 m/sm+12 st/a) and Eigenmannia sp. "B" presents 2n = 38 (14 m/sm+24st/a) and simple differentiated sex chromosomes of the type XX/XY. In both species the Constitutive Heterochromatin (CH) rich in A-T bases is distributed in the centromeric region of all chromosomes. Eigenmannia sp. "B"... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; FISH; Knife fishes; Morphology; Sex chromosomes. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200297 |
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| Kretschmer,Rafael; de Oliveira,Thays Duarte; de Oliveira Furo,Ivanete; Oliveira Silva,Fabio Augusto; Gunski,Ricardo José; del Valle Garnero,Analía; de Bello Cioffi,Marcelo; de Oliveira,Edivaldo Herculano Corrêa; de Freitas,Thales Renato Ochotorena. |
| Abstract An extensive karyotype variation is found among species belonging to the Columbidae family of birds (Columbiformes), both in diploid number and chromosomal morphology. Although clusters of repetitive DNA sequences play an important role in chromosomal instability, and therefore in chromosomal rearrangements, little is known about their distribution and amount in avian genomes. The aim of this study was to analyze the distribution of 11 distinct microsatellite sequences, as well as clusters of 18S rDNA, in nine different Columbidae species, correlating their distribution with the occurrence of chromosomal rearrangements. We found 2n values ranging from 76 to 86 and nine out of 11 microsatellite sequences showed distinct hybridization signals among... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Birds; FISH; Microsatellites; Sex chromosomes; Chromosomal rearrangements. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000100098 |
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| Registros recuperados: 16 | |
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