Data/hora: 02/06/2024 02:30:47

Provedor de dados: | 74
País: | Brazil
Título: | Chromosome characterization in Thinopyrum ponticum (Triticeae, Poaceae) using in situ hybridization with different DNA sequences
Autores: | Brasileiro-Vidal,Ana Christina; Cuadrado,Angeles; Brammer,Sandra P.; Zanatta,Ana Christina A.; Prestes,Ariano M.; Moraes-Fernandes,Maria Irene B.; Guerra,Marcelo.
Data: | 2003-12-01
Ano: | 2003
Palavras-chave: | Thinopyrum; Silver staining; 45S and 5S rDNA; PSc119.2; PAs1.
Resumo: | Thinopyrum ponticum (2n = 10x = 70, JJJJsJs) belongs to the Triticeae tribe, and is currently used as a source of pathogen resistance genes in wheat breeding. In order to characterize its chromosomes, the number and position of 45S and 5S rDNA sites, as well as the distribution of the repetitive DNA sequences pAs1 and pSc119.2, were identified by fluorescent in situ hybridization. The number of nucleoli and NORs was also recorded after silver nitrate staining. Seventeen 45S and twenty 5S rDNA sites were observed on the short arms of 17 chromosomes, the 45S rDNA was always located terminally. On three other chromosomes, only the 5S rDNA site was observed. Silver staining revealed a high number of Ag-NORs (14 to 17) on metaphase chromosomes, whereas on interphase nuclei there was a large variation in number of nucleoli (one to 15), most of them (82.8%) ranging between four and nine. The pAs1 probe hybridized to the terminal region of both arms of all 70 chromosomes. In addition, a disperse labeling was observed throughout the chromosomes, except in centromeric and most pericentromeric regions. When the pSc119.2 sequence was used as a probe, terminal labeling was observed on the short arms of 17 chromosomes and on the long arms of five others. The relative position of 45S and 5S rDNA sites, together with the hybridization pattern of pAs1 and pSc119.2 probes, should allow whole chromosomes or chromosome segments of Th. ponticum to be identified in inbred lines of wheat x Th. ponticum.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000400014
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572003000400014
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.26 n.4 2003
Fonte: | info:eu-repo/semantics/openAccess