Some sequences in the genome cause genes to be switched on or off. Until now, each of these gene switches, or so-called enhancers, was thought to have its own place on the DNA. Different enhancers are therefore separated from each other, even if they control the same gene, and switch it on in different parts of the body.
A recent study from the University of Bonn and the LMU Munich challenges this idea. The findings are also important because gene switches are thought to play a central role in evolution. The study has been published in the journal Science Advances .
The blueprint of plant and animal forms is encoded in their DNA. But only a small part of the genome - about two percent in mammals - contains genes, the instructions for making proteins. The rest largely controls when and where these genes are active: how many of their transcripts are produced, and thus how many proteins are made from these transcripts.
Some of these regulatory sequences, called 'enhancers', work like dimmer switches used to modulate the light in our living room. Indeed, they specifically increase the expression of a particular gene, where and when this gene is required. Genes controlling morphology often respond to several independent enhancers, each determining the expression of the gene in a different body part.
Enhancers controlling Drosophila coloration Until now, enhancers were thought to be modular. The term implies that each enhancer occupies an isolated stretch of DNA. "We have shown, ho.