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Registros recuperados: 10 | |
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Moreira,Camila Nascimento; Di-Nizo,Camilla Bruno; Silva,Maria José de Jesus; Yonenaga-Yassuda,Yatiyo; Ventura,Karen. |
Pseudoryzomys simplex, the false rice rat, is a monotypic genus of the Oryzomyini tribe (Sigmodontinae) distributed in part of Bolivia, Paraguay, Argentina and Brazil. Its diploid number has been described as 56 acrocentric chromosomes decreasing in size and no karyotype figure has been depicted. Herein, we present karyotypic data on P. simplex, including chromosome banding and molecular fluorescent in situ hybridization using telomeric sequences and the whole X-chromosome of its sister clade Holochilus brasiliensis (HBR) as probes. A case of remarkable autosomal heteromorphism due to the presence of a whole heterochromatic arm leading to the variability of FN is reported, as well as the occurrence of regions of homology between the X and Y chromosomes... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; Fluorescent in situ hybridization; Heterochromatin; Oryzomyini. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000200010 |
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Paresque,Roberta; Silva,Maria José de Jesus; Yonenaga-Yassuda,Yatiyo; Fagundes,Valéria. |
The karyotypes of 85 specimens of Oligoryzomys nigripes (Rodentia, Sigmodontinae) collected in the Cerrado and Atlantic Forest of seven states of Brazil were analyzed. Eighty four specimens presented a karyotype with 2n = 62 and one individual had 2n = 61 due to a monosomy of the X chromosome. High levels of intra- and inter-population karyotypic variability, due to sex chromosomes heteromorphisms and pericentric inversions in four autosomes (pairs 2, 3, 4 and 8), led to a variation of the autosomal arm numbers (fundamental number, FN) from 78 to 82. Synaptonemal complex analyses revealed normal meiosis in males heterozygous for pericentric inversions. We found 39 different cytotypes, 27 of which are herein described for the first time. A literature survey... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pericentric inversion; Oryzomyini; Oligoryzomys nigripes; Rodentia; Clinal variation. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100010 |
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Laguna,Marcia Maria; Amaro,Renata Cecília; Mott,Tamí; Yonenaga-Yassuda,Yatiyo; Rodrigues,Miguel Trefaut. |
The karyotype of Amphisbaena ridleyi, an endemic species of the archipelago of Fernando de Noronha, in State of Pernambuco, Brazil, is described after conventional staining, Ag-NOR impregnation and fluorescence in situ hybridization (FISH) with a telomeric probe. The diploid number is 46, with nine pairs of macrochromosomes (three metacentrics, four subtelocentrics and two acrocentrics) and 14 pairs of microchromosomes. The Ag-NOR is located in the telomeric region of the long arm of metacentric chromosome 2 and FISH revealed signals only in the telomeric region of all chromosomes. Further cytogenetic data on other amphisbaenians as well as a robust phylogenetic hypothesis of this clade is needed in order to understand the evolutionary changes on... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amphisbaena ridleyi; Karyotype; Fernando de Noronha; Ag-NOR; FISH with telomeric probes. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000100011 |
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Pereira,Núbia P.; Ventura,Karen; Silva Júnior,Magno C.; Silva,Daniela de Melo e; Yonenaga-Yassuda,Yatiyo; Pellegrino,Katia C. M.. |
The karyotypes of 23 specimens belonging to 16 species from nine genera of Brazilian marsupials (family Didelphidae) were studied. The animals were collected in eight localities of Cerrado or Atlantic Forest biomes in the states of Goiás, Tocantins and São Paulo. The karyotypes were analyzed after conventional Giemsa staining and silver staining of the nucleolus organizer regions (Ag-NORs). New karyotypic data were obtained for Gracilinanus microtarsus (2n = 14, FN = 24), Marmosops paulensis (2n = 14, FN = 24) , Micoreus paraguayanus (2n = 14, FN = 20) and Monodelphis rubida (2n = 18, FN = 32) and are discussed in detail. The karyotypes of G. microtarsus , M. paulensis and M. paraguayanus include three large pairs of submetacentrics (pairs 1, 2... |
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Palavras-chave: Marsupials; Karyotypes; Cytogenetics; Didelphidae; NORs. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000500014 |
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Ventura,Karen; Ximenes,Gilson Evaristo Iack; Pardini,Renata; Sousa,Marcos A. Nóbrega de; Yonenaga-Yassuda,Yatiyo; Silva,Maria José de J.. |
The genus Callistomys belongs to the rodent family Echimyidae, subfamily Echimyinae, and its only living representative is Callistomys pictus, a rare and vulnerable endemic species of the state of Bahia, Brazil. Callistomys has been previously classified as Nelomys, Loncheres, Isothrix and Echimys. In this paper we present the karyotype of Callistomys pictus, including CBG and GTG-banding patterns and silver staining of the nucleolus organizer regions (Ag-NORs). Comments on Callistomys pictus morphological traits and a compilation of Echimyinae chromosomal data are also included. Our analyses revealed that Callistomys can be recognized both by its distintinctive morphology and by its karyotype. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Callistomys; Karyotype; Banding patterns; Echimyinae. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000400016 |
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Fagundes,Valéria; Christoff,Alexandre Uarth; Amaro-Ghilard,Renata Cecília; Scheibler,Daniel R.; Yonenaga-Yassuda,Yatiyo. |
This is the first time the karyotype of the Brazilian squirrel Sciurusaestuans ingrami, with 2n = 40, is described. The karyotype of this species comprises 18 pairs of biarmed and one minute pair of acrocentric autosomes, a medium-sized submetacentric X and a medium-sized acrocentric Y. Four pairs have an interstitial secondary constriction, co-located with nucleolar organizer regions (NORs), identified by silver-staining technique and fluorescent in situ hybridization (FISH) with ribosomal 18S/28S probes. The occurrence of multiple interstitial NORs is rare in rodents, and this is one of the few examples, identified by a molecular cytogenetics approach. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Squirrels; Chromosomes; Karyotype; NORs; Rodentia. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300007 |
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Silva,Maria José de J.; Patton,James L.; Yonenaga-Yassuda,Yatiyo. |
Comparison of G-bands from 2n = 10 and 2n = 16 karyotypes of Akodon revealed tandem fusions, pericentric inversions and Robertsonian rearrangement in autosomes and addition/deletion of constitutive heterochromatin in sex chromosomes. Cytochrome-b sequences indicate that the 2n = 10 karyotype is a new species and show it to be a sister taxon of the 2n = 14, 2n = 15 and 2n = 16 karyotypes. Indeed, this group shows a particular evolutionary situation in which a unique taxonomic unit based on morphological data can be detected, but, karyologically, it can be separated into two groups (2n = 14-15-16 and 2n = 10). Cytochrome-b sequences show a finer resolution, indicating that these four karyotypes represent three molecular entities (2n = 14-15, 2n = 16 and 2n =... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Akodon; Cytochrome-b; G-bands; Karyotypical evolution; Phylogeny. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000300012 |
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Ventura,Karen; Silva,Maria José de Jesus; Yonenaga-Yassuda,Yatiyo. |
A novel karyotype with 2n = 50, FN = 48, was described for specimens of Thaptomys collected at Una, State of Bahia, Brazil, which are morphologically indistinguishable from Thaptomys nigrita, 2n = 52, FN = 52, found in other localities. It was hence proposed that the 2n = 50 karyotype could belong to a distinct species, cryptic of Thaptomys nigrita, once chromosomal rearrangements observed, along with the geographic distance, might represent a reproductive barrier between both forms. Phylogenetic analyses using maximum parsimony and maximum likelihood based on partial cytochrome b sequences with 1077 bp were performed, attempting to establish the relationships among the individuals with distinct karyotypes along the geographic distribution of the genus;... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atlantic Rainforest; Cytochrome b; Endemism; Molecular phylogeny; Thaptomys. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200010 |
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Registros recuperados: 10 | |
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