June 19th, 2006



о временном кодировании

Writing in the June 16 edition of the journal Cell, the research team found that a molecule of RNAP makes frequent pauses at specific sites along the DNA double helix. - Press Release

“Our measurements are accurate to one-tenth of a nanometer—the width of a single hydrogen atom,” Block explained. “When you study an RNAP enzyme at that scale, you discover that it moves along the DNA for a while, and then for no apparent reason it appears to stop. Some pauses we’ve already figured out. The really long ones, which happen every 1,000 bases or so and last up to 30 minutes, often occur when the enzyme makes a mistake. Then, it’s got to back up and correct the mistake. But for every one of those, there are roughly 10 ubiquitous pauses that only last about 1 second and occur every 100 bases or so—and their role is really something of a mystery.”

Cell, June 2006
Sequence-Resolved Detection of Pausing by Single RNA Polymerase Molecules

Current Biology, May 2006
Transcriptional Pulsing of a Developmental Gene
...By means of an in vivo RNA detection technique we have directly visualized transcription of an endogenous developmental gene. We found discrete “pulses” of gene activity that turn on and off at irregular intervals. Surprisingly, the length and height of these pulses were consistent throughout development. However, there was strong developmental variation in the proportion of cells recruited to the expressing pool. Cells were more likely to reexpress than to initiate new expression, indicating that we directly observe a transcriptional memory. In addition, we used a clustering algorithm to reveal synchronous transcription initiation in neighboring cells.

да, организм - штука четырехмерная...