During development, an embryo’s cells divide many times to form different tissues and organs. To understand how this process works, developmental biologists track dividing cells and their progeny, generating maps of cell lineages in the growing body. A newly-developed microscopic technique makes it possible to analyze 3D time-lapse videos of a developing embryo and track the locations and behaviors of thousands of cells simultaneously. Here, the technique is applied to an early fruit fly (Drosophila) embryo. At this stage, the embryo does not consist of individual cells but rather a cytoplasmic mass with many nuclei. The image shows part of a single frame from a 3D time-lapse movie of the embryo with colored ellipsoids that were digitally superimposed for ease of tracking individual nuclei.
A fruit-fly embryo genetically labeled with a fluorescent marker was imaged using the simultaneous multi-view light-sheet microscope (SiMView). The process allows the localization of all nuclei in 3D in vivo. Once the image is obtained, a computer superimposes colored ellipsoids to each nuclei, and automated processing algorithms track nuclei movement and division during the course of the 3D time-lapse movie.
Fernando Amat PhD and Philipp Keller PhD, HHMI Janelia Research Campus.