Analysis of Bicoid morphogen gradient formation by quantitative measurements of protein lifetime

DURRIEU, LUCÍA; SAUNDERS, TIMOTHY; KIRRMAIER, DANIEL; KNOP, MICHAEL; HUFNAGEL, LARS

Heidelberg

Conferencia; EMBO|EMBL Symposium: Seeing is Believing - Imaging the Processes of Life.; 2015

EMBO

Morphogen gradients are a widely used mechanism for providing positional information during development. In Drosophila early embryos, the Bicoid (Bcd) morphogen gradient determines the patterning across the anterior-posterior axis. Despite being extensively studied, the dynamics and the molecular mechanisms of Bcd gradient formation are still controversial. Here, we investigate the use of fluorescent timer reporters (a tandem of a fast and a slow maturing fluorophore) to determine key kinetic parameters of gradient formation. Fusing Bcd to fluorescent timer reporters enabled us to acquire spatially resolved maps of its diffusion and lifetime during embryonic development. Our analysis of these kinetic maps allows to discriminate between competing models. We combine the use of the fluorescent timers with light-sheet microscopy to acquire in toto time series of Bcd dynamics with subcellular resolution and high signal to noise ratio. Our results provide an independent measurement of Bcd dynamics, and highlight new methods for exploring morphogen dynamics in live embryos.