Title:	Karyotype characterization of Crotalaria juncea (L.) by chromosome banding and physical mapping of 18S-5.8S-26S and 5S rRNA gene sites.
Authors:	MONDIN, M. SANTOS-SEREJO, J. A. dos AGUIAR-PERECIN, M. L. R.
Affiliation:	MATEUS MONDIN, ESCOLA SUPERIOR DE AGRICULTURA LUIZ DE QUEIROZ; JANAY ALMEIDA DOS SANTOS-SEREJO, CNPMF; MARGARIDA L. R. AGUIAR-PERECIN, ESCOLA SUPERIOR DE AGRICULTURA LUIZ DE QUEIROZ.
Date Issued:	2007
Citation:	Genetics and Molecular Biology, Ribeirão Preto, v. 30, n. 1, p. 65-72, 2007.
Description:	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 heterochromatic regions around the secondary constriction and on the long arms of chromosomes 1 and 4. Fluorescence in situ hybridization (FISH) revealed 18S-5.8S-26S rRNA gene sites (45S rDNA) on chromosomes 1 and 4, and one 5S rDNA locus on chromosome 1. All the rDNA sites were co-located with the positive-CMA/DA bands, suggesting they were very rich in GC. Silver staining revealed signals at the main 45S rDNA locus on chromosome 1 and, in some cells, chromosome 4 was labeled. Two small nucleoli were detected in a few interphase cells, suggesting that the minor site on chromosome 4 could be active at some stages of the cell cycle.
Thesagro:	Crotalária Juncea Leguminosa Cariótipo
NAL Thesaurus:	fish
Keywords:	Crotalaria juncea karyotype C-bands Fluorescent banding rDNA sites Ag-NOR
DOI:	https://doi.org/10.1590/S1415-47572007000100013
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPMF)