Encontrados 5 documentos, a visualizar página 1 de 1
Transcriptionally active heterochromatin in rye B chromosomes
Carchilan, Mariana; Delgado, Margarida; Ribeiro, Teresa; Nunes, Pedro Costa; Caperta, A.; Morais-Cecílio, L.; Jones, R. Neil; Viegas, WandaB chromosomes (Bs) are dispensable components of the genomes of numerous species. Thus far, there is a lack of evidence for any transcripts of Bs in plants, with the exception of some rDNA sequences. Here, we show that the Giemsa bandingpositive heterochromatic subterminal domain of rye (Secale cereale) Bs undergoes decondensation during interphase. Contrary to the heterochromatic regions of A chromosomes, this...
Ribosomal DNA heterochromatin in plants
Neves, N.; Delgado, M.; Silva, M.; Caperta, A.; Morais-Cecílio, L.; Viegas, W.The aim of this review is to integrate earlier results and recent findings to present the current state-of-the art vision concerning the dynamic behavior of the ribosomal DNA (rDNA) fraction in plants. The global organization and behavioral features of rDNA make it a most useful system to analyse the relationship between chromatin topology and gene expression patterns. Correlations between several heterochromat...
Different numbers of rye B chromosomes induce identical compaction changes in d...
Delgado, M.; Caperta, A.; Ribeiro, T.; Viegas, W.; Jones, R.N.; Morais-Cecilio, L.In rye each B chromosome (B) represents 5.5% of the diploid A genome. Rye Bs have several nuclear to whole plant effects although they seem to bear no genes except for the ones that lead to their maintenance within a population. In this context, and considering that rye Bs are enriched in repetitive non-coding regions that build up heterochromatin (het), we investigated the influence of Bs on the organization o...
Genome restructuring in rye affects the expression, organization and dispositio...
Caperta, A.; Neves, Nuno; Morais-Cecílio, L.; Malhó, Rui; Viegas, WandaResearch Article ; The standard rye cultivar ‘Imperial’ and a structural variant carrying an intact 1R chromosome and two telocentric 1R chromosomes (short and long arms) were used to investigate expression patterns of homologous rDNA loci, and the influence of chromosome structural change on their interphase organisation and relative disposition. Sequential silver staining and in situ hybridization with the r...
Reprogramming of rye rDNA in triticale during microsporogenesis
Silva, M.; Queiroz, A.; Neves, N.; Barão, A.; Castilho, A.; Morais-Cecilio, L.; Viegas, W.To test the hypothesis that interspecific genomic and chromosome interactions leading to nucleolar dominance could be reprogrammed in meiosis, we compared the expression of distinct nucleolar organizing region (NOR) loci in hexaploid triticale root tip meristematic cells, pollen mother cells and young pollen grains. Interphase and metaphase cells were silver stained to quantify nucleoli and active NOR loci resp...
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