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rRNA gene activity and control of expression mediated by methylation and imprinting during embryo development in wheat x rye hybrids
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Autores
Orientador(es)
Resumo(s)
Ribosomal RNA genes originating from one
parent are often suppressed in interspecific hybrids. We
show that treatments during germination with the
cytosine analogue 5-azacytidine stably reactivate the
expression of the suppressed rRNA genes of rye origin in
the wheat x rye amphiploid, triticale, by preventing
methylation of sites in the rye rDNA. When 5-azacytidine
is applied to embryos of triticale and
wheat x rye F1 hybrids nine, or more, days after fertilization,
rye rRNA gene expression is stably reactivated in
the resulting seedling. Earlier treatments have no effect
on rye rRNA gene expression, indicating that undermethylation
of DNA early in embryo development is
reversible. After 9 days, the methylation status of rRNA
genes in maintained throughout development. Since the
change in expression follows a methylation change at
particular restriction-enzyme sites, the data establish a
clear correlation between gene activity and methylation
in plants.
Descrição
Palavras-chave
nucleolar dominance genomic imprinting NOR expression silver staining
Contexto Educativo
Citação
"Theoretical and Applied Genetics". ISSN 0040-5752. 91 (1995). 529-533