Methylation of B-hordein genes in barley endosperm is inversely correlated with gene activity and affected by the regulatory gene Lys3.

AUTOR(ES)

Sørensen, M B

RESUMO

The methylation status of B-hordein genes in the developing barley endosperm was analyzed by digestion with methylation-sensitive restriction enzymes. Southern blotting revealed specific demethylation of Hpa II sites in DNA from wild-type endosperm, whereas leaf DNA and lys3a mutant endosperm DNA were highly methylated at these sites. Similar methylation patterns were observed at an Ava I site situated at position -260 in the B-hordein promoter. This differential methylation was confirmed by genomic sequencing with ligation-mediated PCR. The analyzed sequence covers most of the B-hordein promoter and includes 10 CpGs from the promoter and 4 CpGs from the adjacent coding region. These sites were all hypomethylated in wild-type endosperm, whereas--except for three partially methylated sites--full methylation was seen in leaf DNA. The four sites in the coding region were partially methylated in lys3a endosperm DNA, but the promoter sites remained highly methylated. The possible role of methylation in the regulatory function of the Lys3 gene product is discussed.

Documentos Relacionados

• Primer-mediated in situ detection of the B-hordein gene cluster on barley chromosome 1H.
• Expression of the J chain gene during B cell differentiation is inversely correlated with DNA methylation.
• Nucleotide sequence of a B1 hordein gene and the identification of possible upstream regulatory elements in endosperm storage protein genes from barley, wheat and maize.
• Methylation of integrated adenovirus type 12 DNA sequences in transformed cells is inversely correlated with viral gene expression.
• Silencing of human polycomb target genes is associated with methylation of histone H3 Lys 27