Consulta: creatorFacets:"Yonenaga-Yassuda,Yatiyo"
Registros recuperados: 10
Data/hora: 02/06/2024 02:16:37

Karyological study of Amphisbaena ridleyi (Squamata, Amphisbaenidae), an endemic species of the Archipelago of Fernando de Noronha, Pernambuco, Brazil
Provedor de dados: Genetics and Molecular Biology
Autores: 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

Chromosomal banding patterns in the eyelid-less microteiid lizard radiation: The X1X1X2X2:X1X2Y sex chromosome system in Calyptommatus and the karyotypes of Psilophthalmus and Tretioscincus (Squamata, Gymnophthalmidae)
Provedor de dados: Genetics and Molecular Biology
Autores: Yonenaga-Yassuda,Yatiyo; Rodrigues,Miguel Trefaut; Pellegrino,Katia Cristina Machado.
Cytogenetic studies were performed on five closely related microteiid lizards (Gymnophthalmini), three Calyptommatus species and Psilophthalmus paeminosus from the sand dunes of the middle São Francisco river in the semiarid caatinga of the Brazilian state of Bahia and Tretioscincus oriximinensis from the Brazilian Amazon region. The diploid chromosome number in Calyptommatus species was 2n = 58 in females and 2n = 57 in males due to a multiple X1X1X2X2:X1X2Y sex chromosomes system, while P. paeminosus was 2n = 44 (20M+24m): where M = macrochromosomes and m = microchromosomes) and T. oriximinensis 2n = 42 (18M+24m). A single pair of silver staining nucleolar organizing regions (Ag-NORs) characterizes all five species. Incorporation of 5-BrdU...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gymnophthalmidae; Banding patterns; Karyotypes; Multiple sex chromosomes.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500009

Nine karyomorphs for spiny rats of the genus Proechimys (Echimyidae, Rodentia) from North and Central Brazil
Provedor de dados: Genetics and Molecular Biology
Autores: Machado,Taís; Silva,Maria José de J.; Leal-Mesquita,Emygdia Rosa; Carmignotto,Ana Paula; Yonenaga-Yassuda,Yatiyo.
Spiny rats of the genus Proechimys are morphologically diverse, widely distributed and have diploid numbers ranging from 2n = 14-16 to 2n = 62. In this paper we present cytogenetical data and brief comments on morphological and biogeographical issues related to spiny rats. In our sample of 42 spiny rats collected from 12 Brazilian Amazonian tropical rainforest and the Cerrado (Brazilian savanna) sites we detected nine karyological entities: four different karyomorphs with 2n = 30, three with 2n = 28, one with 2n = 15 and one with 2n = 44. Based on qualitative morphological characters these karyomorphs can be allocated to five species within the goeldii, guyannensis and longicaudatus species groups.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Proechimys; Rodents; Cytogenetics; Karyomorph; Morphology.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500007

Karyotype characterization and nucleolar organizer regions of marsupial species (Didelphidae) from areas of Cerrado and Atlantic Forest in Brazil
Provedor de dados: Genetics and Molecular Biology
Autores: 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...
Palavras-chave: Marsupials; Karyotypes; Cytogenetics; Didelphidae; NORs.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000500014

Thaptomys Thomas 1915 (Rodentia, Sigmodontinae, Akodontini) with karyotypes 2n = 50, FN = 48, and 2n = 52, FN = 52: two monophyletic lineages recovered by molecular phylogeny
Provedor de dados: Genetics and Molecular Biology
Autores: 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

Phylogenetic relationships and karyotype evolution in the sigmodontine rodent Akodon (2n = 10 and 2n = 16) from Brazil
Provedor de dados: Genetics and Molecular Biology
Autores: 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

Karyotypic analyses and morphological comments on the endemic and endangered Brazilian painted tree rat Callistomys pictus (Rodentia, Echimyidae)
Provedor de dados: Genetics and Molecular Biology
Autores: 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

Multiple interstitial ribosomal sites (NORs) in the Brazilian squirrel Sciurus aestuans ingrami (Rodentia, Sciuridae) with 2n = 40: an overview of Sciurus cytogenetics
Provedor de dados: Genetics and Molecular Biology
Autores: 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

A remarkable autosomal heteromorphism in Pseudoryzomys simplex 2n = 56; FN = 54-55 (Rodentia, Sigmodontinae)
Provedor de dados: Genetics and Molecular Biology
Autores: 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

Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil
Provedor de dados: Genetics and Molecular Biology
Autores: 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