An early Drosophila embryo visualized using fluorescence microscopy. Nuclei have been false coloured blue and lipid droplets yellow. This embryo, which is ∼0.5 mm in length, is still a single cell containing many nuclei (a syncytium), and most of these are found on the surface. The detail on the right is an expanded head-on view of the surface inside the white rectangle and shows about 32 densely packed nuclei inside an area of about 25 × 25 µm.
IMAGES: MICHAEL WELTE.