Heavy de novo methylation at symmetrical and non-symmetrical sites is a hallmark of RNA-directed DNA methylation.

نویسندگان

  • T Pélissier
  • S Thalmeir
  • D Kempe
  • H L Sänger
  • M Wassenegger
چکیده

Previous analysis of potato spindle tuber viroid (PSTVd) RNA-infected tobacco plants has suggested that an RNA-DNA interaction could trigger de novo methylation of PSTVd transgene sequences. Using the genomic sequencing technique, the methylation pattern associated with the RNA-directed DNA methylation process has been characterized. Three different PSTVd transgene constructs all showed a similar pattern of methylation. Most of the cytosines at symmetrical as well as non-symmetrical positions appeared to be methylated in both DNA strands of the viroid sequences. Heavy methylation was mostly restricted to the viroid cDNA sequences. Flanking DNA regions immediately adjacent to the viroid cDNA displayed a lower but significant level of cytosine methylation. The observation that the heavy methylation was essentially co-extensive with the length of the PSTVd cDNA sequences provided evidence that a direct RNA-DNA interaction can act as a strong and highly specific signal for de novo DNA methylation. These data also confirmed that de novo methylation was not limited to canonical CpG and CpNpG sites, but can also involve all the cytosine residues located in the genomic region where the RNA-DNA interaction takes place.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Cooperative activity of DNA methyltransferases for maintenance of symmetrical and non-symmetrical cytosine methylation in Arabidopsis thaliana

Maintenance of cytosine methylation in plants is controlled by three DNA methyltransferases. MET1 maintains CG methylation, and DRM1/2 and CMT3 act redundantly to enforce non-CG methylation. RPS, a repetitive hypermethylated DNA fragment from Petunia hybrida, attracts DNA methylation when transferred into Petunia or other species. In Arabidopsis thaliana, which does not contain any RPS homologu...

متن کامل

Spatial and Functional Relationships Among Pol V-Associated Loci, Pol IV-Dependent siRNAs, and Cytosine Methylation in the <em>Arabidopsis</em> Epigenome

Multisubunit RNA polymerases IV and V (Pols IV and V) mediate RNA-directed DNA methylation and transcriptional silencing of retrotransposons and heterochromatic repeats in plants. We identified genomic sites of Pol V occupancy in parallel with siRNA deep sequencing and methylcytosine mapping, comparing wild-type plants with mutants defective for Pol IV, Pol V, or both Pols IV and V. Approximate...

متن کامل

The role and importance of DNA methylation in spermatogenesis process

Background: DNA methylation is one of the epigenetic marks that are created by de novo DNA methylation and be maintained through cell division. This process is catalyzed by DNA methyltransferases. DNA methylation establishment in germ line is important, since they have the potential to regulate gene expression in offspring and improper DNA methylation patterns in germ lines has serious conseque...

متن کامل

Role of the DRM and CMT3 Methyltransferases in RNA-Directed DNA Methylation

RNA interference is a conserved process in which double-stranded RNA is processed into 21-25 nucleotide siRNAs that trigger posttranscriptional gene silencing. In addition, plants display a phenomenon termed RNA-directed DNA methylation (RdDM) in which DNA with sequence identity to silenced RNA is de novo methylated at its cytosine residues. This methylation is not only at canonical CpG sites b...

متن کامل

P-70: Evidence for Differential Gene Expression of A Major EpigeneticModifier Enzyme, de novo DNA Methyltransferase 3b, through Vitrification of Mouse Ovary Tissue

Background: Ovarian tissue cryopreservation is a feasible method to preserve female reproductive potential, especially in young patients with cancer or in women at risk of premature ovarian failure. Vitrification has recently emerged as a new trend for biological specimen preservation. On the other hand, gene expression that changes during vitrification can influence oocyte maturation and need ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Nucleic acids research

دوره 27 7  شماره 

صفحات  -

تاریخ انتشار 1999