An enhancer is a sequence of DNA with the power to activate a specific gene. Since Darwin’s theory of natural selection, it is widely accepted that gene sequences are inherited and may be modified, providing a mechanism for change between generations. However, scientists have recently discovered that enhancers can be created completely from scratch (de novo). This completely new mechanism for creating variation between individuals highlights a new mechanism by which species evolve by natural selection. Using a technique known as a reporter assay, the team fused a GFP (green fluorescent protein) gene to one of four newly discovered enhancers, which were injected into fish embryos. They applied a powerful optical imaging technique called confocal microscopy, which highlights enhancer activity in the embryos by means of a green ‘glow’. This pinpoints where each enhancer is driving gene activation.
Written by Roz Pidcock
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.