Embryo.*

The regulatory network that drives the patterning of the early Drosophila embryo is a well-known paradigm to study the general principles underlying spatial and temporal control of gene expression.
Many central rules underlying the architecture of regulatory elements were identified in this network, but the rapidity at which gene expression is modulated over time during early stages of development precluded the investigation of the dynamics of the system with standard techniques based on fluorescent proteins.
In this work we demonstrate the use of an engineered version of the fast-folding/fast-maturating fluorescent protein mNeonGreen as a real-time, quantitative reporter of gene expression. From the time course of the fluorescent reporter signal much information about the system dynamics, like enhancer activity and mRNA concentration, can be deconvolved with high spatial and temporal resolution. We compare our results with previously reported data obtained from the labelling of nascent transcripts based on the MS2 system.