Consulta: subjectFacets:"RDNA sites"
Registros recuperados: 5
Data/hora: 09/06/2024 14:10:20

Karyotype characterization of Crotalaria juncea (L.) by chromosome banding and physical mapping of 18S-5.8S-26S and 5S rRNA gene sites
Provedor de dados: 74
Autores: Mondin,Mateus; Santos-Serejo,Janay A.; Aguiar-Perecin,Margarida L.R.
The chromosomes of Crotalaria juncea, a legume of agronomic interest with a 2n = 16 karyotype composed of metacentric chromosomes, were analyzed using several cytogenetic techniques. C-banding revealed heterochromatic regions around the centromeres in all chromosomes and adjacent to the secondary constriction on the chromosome 1 short arm. Fluorescent staining with the GC-specific chromomycin A3 (CMA) highlighted these heterochromatic regions and a tiny site on the chromosome 1 long arm while the AT-specific stain 4'-6-diamidino-2-phenylindole (DAPI) induced a reversed pattern. Staining with CMA combined with AT-specific distamycin A (DA) counterstaining quenched the pericentromeric regions of all chromosomes, but enhanced fluorescence was observed at the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crotalaria juncea karyotype; C-bands; Fluorescent banding; FISH; RDNA sites; Ag-NOR.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100013

Comparative cytogenetics among species of the Astyanax scabripinnis complex: evolutionary and biogeographical inferences
Provedor de dados: 74
Autores: Vicari,Marcelo Ricardo; Noleto,Rafael Bueno; Artoni,Roberto Ferreira; Moreira-Filho,Orlando; Bertollo,Luiz Antonio Carlos.
Karyotype data are presented for distinct species of the genus Astyanax from four rivers belonging to three different hydrographic basins of the State of Paraná, Brazil (Verde River - Tibagi basin, Açungui River - Ribeira basin, and Santo Antônio and Jaguariaíva Rivers - Jaguariaíva basin). Three karyotypic forms were identified, here denominated karyotype A (2n = 50 chromosomes, with 8m+18sm+10st+14a, and thirteen 18S rDNA sites); karyotype B (2n = 50 chromosomes, with 8m+18sm+10st+1f4a, and four 18S rDNA sites); and karyotype C (2n = 48 chromosomes, with 10m+16sm+10st+12a, and eight 18S rDNA sites). The pattern of constitutive heterochromatin was similar among the three karyotypic forms, with few differences. The 5S rDNA corresponds to a synapomorphic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Karyotype evolution; Cytotaxonomy; RDNA sites; Biogeography.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200002

Intra- and interspecific chromosome polymorphisms in cultivated Cichorium L. species (Asteraceae)
Provedor de dados: 74
Autores: Bernardes,Ebenézer C.S.; Benko-Iseppon,Ana M.; Vasconcelos,Santelmo; Carvalho,Reginaldo; Brasileiro-Vidal,Ana C.
Endive (Cichorium endivia L.) and chicory (C. intybus L.) both have 2n = 18, but until now, there has been no detailed karyomorphological characterization. The present work evaluated five accessions of each species using FISH with rDNA probes and fluorochrome staining with CMA and DAPI. Both species presented distinct banding patterns after fluorochrome staining: while endive had proximal CMA++/DAPI- bands in the short arms of pairs 1, 2 and 3, chicory had proximal CMA-positive bands in chromosomes 1 and 3 and interstitial in the short arm of chromosome 8. Among endive accessions, FISH procedures revealed conserved position and number of 5S and 45S rDNA sites (two and three pairs, respectively), associated with the CMA-positive bands. Notwithstanding,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Compositae; Cichorieae; CMA/DAPI; RDNA sites; Chromosome rearrangements.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000300010

Chromatin differentiation between Theobroma cacao L. and T. grandiflorum Schum
Provedor de dados: 74
Autores: Dantas,Liliane G.; Guerra,Marcelo.
A comparative analysis of mitotic chromosomes of Theobroma cacao (cacao) and T. grandiflorum (cupuaçu) was performed aiming to identify cytological differences between the two most important species of this genus. Both species have symmetric karyotypes, with 2n = 20 metacentric chromosomes ranging in size from 2.00 to 1.19 µm (cacao) and from 2.21 to 1.15 mm (cupuaçu). The interphase nuclei of both species were of the arreticulate type, displaying up to 20 chromocentres, which were more regularly shaped in cacao than in cupuaçu. Prophase chromosomes of both species were more condensed in the proximal region, sometimes including the whole short arm. Both species exhibited only one pair of terminal heterochromatic bands, positively stained with chromomycin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cacao; Cupuaçu; Heterochromatin; Karyotype; RDNA sites; Theobroma.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000100017

Karyotype differentiation in three species of Tripogandra Raf. (Commelinaceae) with different ploidy levels
Provedor de dados: 74
Autores: Marques,André; Roa,Fernando; Guerra,Marcelo.
Most species of the genus Tripogandra (Commelinaceae) are taxonomically poorly circumscribed, in spite of having a relatively stable basic number x = 8. Aiming to estimate the cytological variation among Tripogandra species carrying this base number, several structural karyotypic characters were investigated in the diploid T. glandulosa, the hexaploid T. serrulata, and the octoploid T. diuretica. A careful evaluation of chromosome size and morphology did not reveal clear chromosome homeologies among karyotypes. The mean chromosome size was strongly reduced in the octoploid species, but not in the hexaploid species. They also differed largely in the CMA+ banding pattern and in the number of 5S and 45S rDNA sites per monoploid chromosome complement. All...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tripogandra; Cytotaxonomy; RDNA sites; CMA/DAPI bands; Meiosis.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000400020