Data/hora: 10/06/2024 08:21:48

Provedor de dados: | 74
País: | Brazil
Título: | Karyotype differentiation of four Cestrum species (Solanaceae) based on the physical mapping of repetitive DNA
Autores: | Fregonezi,Jéferson Nunes; Fernandes,Thiago; Torezan,José Marcelo Domingues; Vieira,Ana Odete S.; Vanzela,André Luís Laforga.
Data: | 2006-01-01
Ano: | 2006
Palavras-chave: | Cestrum; Chromosome banding; CSRs; Karyotype evolution; RDNA probes.
Resumo: | We studied the karyotypes of four Brazilian Cestrum species (C. amictum, C. intermedium, C. sendtnerianum and C. strigilatum) using conventional Feulgen staining, C-Giemsa and C-CMA3/DAPI banding, induction of cold-sensitive regions (CSRs) and fluorescent in situ hybridization (FISH) with rDNA probes. We found that the karyotypes of all four species was 2n = 2x = 16, with, except for the eighth acrocentric pair, a predominance of meta- and submetacentric chromosomes and various heterochromatin classes. Heterochromatic types previously unreported in Cestrum as neutral C-CMA3(0)/DAPI0 bands, CMA3+ bands not associated with NORs, and C-Giemsa/CSR/DAPI- bands were found. The heterochromatic blocks varied in size, number, position and composition. The 45S rDNA probe preferentially located in the terminal and subterminal regions of some chromosomes, while 5S rDNA appeared close to the centromere of the long arm of pair 8. These results suggest that karyotype differentiation can occur mainly due to changes in repetitive DNA, with little modification in the general composition of the conventionally stained karyotype.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000100019
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572006000100019
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.29 n.1 2006
Fonte: | info:eu-repo/semantics/openAccess