Characteristics of post‐transcriptional gene silencing

SnapShot: Posttranscriptional Gene Silencing

Posttranscriptional gene silencing in nuclei.

In plants, small interfering RNAs (siRNAs) with sequence homology to transcribed regions of genes can guide the sequence-specific degradation of corresponding mRNAs, leading to posttranscriptional gene silencing (PTGS). The current consensus is that siRNA-mediated PTGS occurs primarily in the cytoplasm where target mRNAs are localized and translated into proteins. However, expression of an inve...

Effects of local mRNA structure on posttranscriptional gene silencing.

Antisense oligodeoxynucleotides (AONs) and short interfering RNAs (siRNAs) effect posttranscriptional gene silencing (PTGS) by hybridizing to an mRNA and then directing its cleavage. To understand the constraints that mRNA structure imposes on AON- vs. siRNA-mediated PTGS, AON- and siRNA-mediated cleavage of defined mRNA structures was monitored in Drosophila embryo whole-cell lysates. We obser...

Dissecting the Mechanisms of Posttranscriptional Gene Silencing Divide and Conquer

genes were tested. In all cases, the transcripts of homolIt is now routine to construct trangenes with defined ogous plant genes became degraded following infection promoters and terminators and express them in a variety (reviewed in Bruening, 1998). PTGS also allows plants of organisms. However, some introduced transgenes to “cure themselves” of infecting viruses even if the are not expressed ...

Transcriptional and posttranscriptional gene silencing are mechanistically related

Two distinct gene-silencing phenomena are observed in plants: transcriptional gene silencing (TGS), which involves decreased RNA synthesis because of promoter methylation, and posttranscriptional gene silencing (PTGS), which involves sequence-specific RNA degradation. PTGS is induced by deliberate [1-4] or fortuitous production (R.v.B., unpublished data) of double-stranded RNA (dsRNA). TGS coul...