Genes that contain instructions for making proteins make up less than 2% of the human genome. Yet, for unknown reasons, most of our genome is transcribed into RNA.
Investigating all transcripts produced in a yeast cell, researchers in the groups of Lars Steinmetz at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and Wolfgang Huber at the European Bioinformatics Institute (EMBL-EBI) in Hinxton, UK found that most regions of the yeast genome produce several transcripts starting at the same promoter. These transcripts are interleaved and overlapping on the DNA. In contrast to what was previously thought, the vast majority of promoters seem to initiate transcription in both directions.
Their study in Nature says it redefines the concept of promoters (the start sites of transcription) contradicting the established notion that they support transcription in one direction only. The results are also representative of transcription in humans, they write.
So is transcription about to get Pluto'ed? Let's not rewrite the textbooks just yet.
Not all of the produced transcripts are stable, many are degraded rapidly making it difficult to observe what they do.
While some of the RNA molecules might be 'transcriptional noise' without function, other transcripts control the expression of genes and production of proteins. The act of transcription itself is also likely to play an important role in regulation of gene expression. Transcribing one stretch of DNA might either help or in other cases interfere with the transcription of a gene close by. Moreover, transcripts without a current purpose can serve as 'raw material for evolution' and acquire new functions over time.
The results shed light on the complex organization of the yeast genome and the insights gained extend to transcription in humans. A better understanding of transcription mechanisms could find application in new technologies to tune gene regulation in the future.
Article: Xu, Z., Wei, W., Gagneur, J., Perocchi, F., Clauder-Münster, S., Camblong, J., Guffanti, E., Stutz, F., Huber, W.&Steinmetz, L.M. Bidirectional promoters generate pervasive transcription in yeast, Nature, 25 January 2009
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Your Probiotic Probably Has Gluten
- Mystery Of Morgellons - Disease Or Delusion - Scientific Hypothesis Of Connection With Lyme Disease
- Mummy Madness In The Anatomical Record - All Open Access
- Early Christian Apocalypse: St. Paul Gave Us Heaven And Hell Many Times Over
- Highest Energy Collisions ? Not In My Book
- Will We Soon Have A 2-D Liquid?
- Blue Buffalo Admits Its Pet Food Contains The Poultry Byproduct It Ridicules In Competitors
- "Here's one good answer to the question of your title: http://rt.com/news/261673-india-gmo..."
- "I'm fine, don't have Morgellons or chronic lyme disease, and thinking about the condition doesn't..."
- "[t]he only thing that can set us right is a katalepsis, a seizure by grace, something transformative..."
- "Well, Soon after having sent my previous comment I got a message from Neil Sloane that he had published..."
- "This phenomenon is familiar to market researchers. (I used to be one.) Causes are:  ..."
- Savannahs slow climate change
- Sudden onset of ice loss in Antarctica detected
- Proton therapy has fewer side effects in esophageal cancer patients
- Mood instability common to mental health disorders and associated with poor outcomes
- Depression associated with 5-fold increase in mortality risk for heart failure patients