Dataset Information

Robertson's Mutator transposons in A. thaliana are regulated by the chromatin-remodeling gene Decrease in DNA Methylation (DDM1).

ABSTRACT: Robertson's Mutator transposable elements in maize undergo cycles of activity and then inactivity that correlate with changes in cytosine methylation. Mutator-like elements are present in the Arabidopsis genome but are heavily methylated and inactive. These elements become demethylated and active in the chromatin-remodeling mutant ddm1 (Decrease in DNA Methylation), which leads to loss of heterochromatic DNA methylation. Thus, DNA transposons in plants appear to be regulated by chromatin remodeling. In inbred ddm1 strains, transposed elements may account, in part, for mutant phenotypes unlinked to ddm1. Gene silencing and paramutation are also regulated by DDM1, providing support for the proposition that epigenetic silencing is related to transposon regulation.

SUBMITTER: Singer T

PROVIDER: S-EPMC312647 | biostudies-literature | 2001 Mar

REPOSITORIES: biostudies-literature

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Robertson's Mutator transposons in A. thaliana are regulated by the chromatin-remodeling gene Decrease in DNA Methylation (DDM1).

Singer T T Yordan C C Martienssen R A RA

Genes & development 20010301 5

Robertson's Mutator transposable elements in maize undergo cycles of activity and then inactivity that correlate with changes in cytosine methylation. Mutator-like elements are present in the Arabidopsis genome but are heavily methylated and inactive. These elements become demethylated and active in the chromatin-remodeling mutant ddm1 (Decrease in DNA Methylation), which leads to loss of heterochromatic DNA methylation. Thus, DNA transposons in plants appear to be regulated by chromatin remodel ...[more]

PMID: 11238379

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Project description:The purpose of the McrBC methylation microarray assay is to determine which regions of a genome are methylated versus those that are unmethylated in a single Arabidopsis thaliana genotype. McrBC is a methylation-sensitive enzyme that restricts DNA only at purine-Cmethyl half sites when separated between 50bp and 3kb. A designated amount of DNA from a particular genotype is sheared to a size range of 1kb-10kb using nebulization. We restrict half of the nebulized DNA with McrBC, and the methylated fraction is then removed from the unmethylated fraction through gel purification of DNA fragments greater than 1kb.* The remaining nebulized DNA is subjected to the same gel purification scheme, but with no McrBC treatment. In a single hybridization, the untreated sample is labeled with Cy5 and the McrBC-treated sample with Cy3. Thus, after labeling and microarray hybridization, the ratio of normalized Cy5 to normalized Cy3 represents the relative methylation at the sequence represented by the spot on the microarray. Dye swap analysis is carried out to take account of experimental variation by repeating the hybridization with identical samples labeled with Cy3 and Cy5, respectively. ddm1 seedlings, 9 days old. The two samples in this series are complementary hybridizations in a dye-swap analysis. This is the normalized result of the paired dye swap samples VC131 and VC135. The ANOVA model of Kerr, Martin and Churchill (2000) was used to analyze the data from the dye-swap experiments, with terms included to account for gene, dye-by-gene, treatment-by-gene, and random error terms. The style of hypothesis test proposed by Black and Doerge (2002) was applied to each of the features represented on each array, with rejection of the null hypothesis indicating a significant change in fluorescence intensity. To account for the number of hypothesis tests being made, and thus provide some level of error rate control, significance was assessed using both family-wise error rate (FWER) and false discovery rate (FDR) controlling methods. The step-down multiple comparisons procedure of Holm (1979) was used to control the FWER below alpha = 0.01, while the step-up procedure of Benjamini and Hochberg (1995) was used to control the FDR below alpha = 0.01. For the purposes of this experiment, the hypotheses were assumed to be independent. Features found to be significantly enriched for DNA methylation after hypothesis-testing with a controlled error rate are flagged in the last two columns. Keywords: other

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Dataset Information

Robertson's Mutator transposons in A. thaliana are regulated by the chromatin-remodeling gene Decrease in DNA Methylation (DDM1).

Publications

Robertson's Mutator transposons in A. thaliana are regulated by the chromatin-remodeling gene Decrease in DNA Methylation (DDM1).

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