Related Experiment Video
Updated: Sep 6, 2025
06:16
mirMachine: A One-Stop Shop for Plant miRNA Annotation
Published on: May 1, 2021
2.6K
Ovule siRNAs methylate protein-coding genes in trans
Diane Burgess1, Hiu Tung Chow2, Jeffrey W Grover3
1Department of Plant and Microbial Biology, The University of California, Berkeley, California 94720, USA.
The Plant Cell
|July 5, 2022
Summary
Small interfering RNAs (siRNAs) in Brassica rapa trigger DNA methylation in trans, silencing genes and impacting reproduction. This RNA-directed DNA methylation (RdDM) process is crucial for plant reproductive success.
Area of Science:
- Plant Molecular Biology
- Epigenetics
- Genomics
Background:
- RNA-directed DNA methylation (RdDM) uses 24-nucleotide small interfering RNAs (siRNAs) to maintain DNA methylation in plant euchromatic transposable elements.
- While dispensable for growth in Arabidopsis thaliana, RdDM is essential for reproduction in Brassica rapa.
- Abundant 24-nt siRNAs in maternal reproductive tissues originate from specific loci called siren loci.
Purpose of the Study:
- To investigate the role of siRNAs in female reproductive tissues in Brassica rapa.
- To elucidate the mechanism of trans-generational epigenetic inheritance mediated by siRNAs.
- To understand the impact of RdDM on gene expression and plant reproduction.
Main Methods:
- Analysis of siRNA production from gene fragments within siren loci.
- Investigation of trans-methylation at related protein-coding genes.
- Identification of DNA transposon consensus sequences associated with siren expression and CLASSY3 recruitment.
Main Results:
- siRNAs produced from gene fragments in siren loci trigger methylation in trans at homologous protein-coding genes in female reproductive tissues.
- This trans-methylation leads to the silencing of some target genes.
- A consensus sequence in DNA transposons is linked to abundant siren expression, potentially via CLASSY3.
Conclusions:
- RdDM influences gene expression in Brassica rapa through trans-methylation in female reproductive tissues.
- This mechanism sheds light on the critical role of RdDM in plant reproduction and may explain seed abortion in RdDM mutants.
- The findings highlight a novel pathway for epigenetic regulation impacting plant fertility.
Related Concept Videos
02:30siRNA - Small Interfering RNAs
17.0K
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
17.0K
02:30Small interfering RNAs (siRNA)
3.6K
3.6K
01:23Regulation of Expression at Multiple Steps
993
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
993
02:57piRNA - Piwi-interacting RNAs
7.0K
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
7.0K
01:23RNA Interference
26.4K
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
26.4K
02:39lncRNA - Long Non-coding RNAs
8.9K
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA...
8.9K