Getting Repetitive in Keystone

Repeats appear important in gene silencing. Repeats appear important in gene silencing. At least two talks at the Keystone Symposium Conference on Epigenetics and Chromatin Remodeling in Development implicate the power of tandem repeats in RNA-interference induced silencing. Rob Martienssen of Cold Spring Harbor talked about silencing of transposable elements (in keeping with the grand history of his institution). He explained how his lab has found that RNAi-independent and RNAi-dependent mechanisms are required to silence different TEs, and how histone modification differs accordingly. Recapping an idea he had put forth a while back he talked about how tandem repeats appear much more effective in RNAi mediated silencing. The reason, it seems, is that long tandemly repeated RNA transcripts destined for dicer could provide a much bigger pool of short interfering RNAs (siRNAs) and so have better likelihood of hitting the right complementarity for silencing genes at the transcriptional level. This...