Impact of cis-reg sequences on transcriptional noise during development

A major surprise of recent live imaging studies is the discovery that transcription is not always continuous but occurs through bursts. These bursts have a great potential for generating cell to cell variability (noise) in gene expression. Development is a time when small initial changes can permanently propagate forward, to lead to larger phenotypic effects. Thus, these fluctuations in gene expression must be controlled, to ensure accuracy and reproducibility. In the context of early drosophila embryogenesis, despite these inherent fluctuations, mRNAs are remarkably homogeneously distributed. Understanding the various sources of transcriptional noise and its buffering is a fundamental yet unresolved question. Thus, to decipher the mechanisms responsible for transcriptional precision during development, it is essential to integrate multiple scales in time and space. By combining quantitative imaging, genetic manipulations and modelling, our research grasps multiple spatio-temporal scales and is able to test functional relevance of the discovered mechanisms in vivo.