In recent years, advances in imaging probes, microscopy techniques and bioinformatics image analysis have markedly expanded the imaging toolbox available to developmental biologists. Apart from conventional phenotypic studies, embryonic development is increasingly investigated in vivo with improved accuracy in time and space and more detailed quantitative analyses down to the single-cell level (reviewed in). To get more insight into the elaborate cell dynamics (i.e. cell division, motility and morphological changes) and protein dynamics (i.e.