Measuring Gene Expression in Fly Embryos: From Single Molecules to Network Dynamics

Abstract

The nodes of many genetic networks that are active during early development are transcription factors, i.e. proteins that cross-regulate each other via activating or repressive interactions. Hence, in order to understand generic properties of such transcription networks, obtaining quantitative access to the molecular players is key. In particular, in addition to proteins, quantitative handles to other molecular species such as RNA-polymerases and mRNA molecules are crucial to understand the transition from one network node to the next. I will report on our recent progress in developing methods to count individual molecules of mRNA in intact fly embryos, and to monitor in vivo the transcriptional activity of nascent mRNA at their site of production on the DNA. Initial applications and results using these methods will also be discussed.