Embryogenesis describes the gradual process of developing differentiated cells, tissues, organs and eventually, specific body structures out of an initially uniform cell mass. The precise kinetics, dynamics and signaling events taking place during this period are of major interest for developmental biologists. Studies are typically performed with abundantly available and fast-growing model systems like flies, frogs or worms.
In this use case, we study a nematode (C. elegans) embryo during the very early stage of embryonic cell divisions. C. elegans is a particularly important model organism for developmental biology, because it develops with timed cell divisions and cell differentiation dynamics, reaching an adult stage with precisely 959 cells. This allows study of the function of genes or drugs by observing perturbations in the normal development scheme1.
Microscopic imaging has been established as a key method for studying early embryos, because only microscopy can decipher the spatial context of cell divisions and cell migration patterns. However, commonly used microscopy techniques often are too invasive for observing these delicate processes over extended periods of time. In this use case, we show how ZEISS Lattice Lightsheet 7 can be used to make gentle long-term imaging of sensitive specimens like these embryos feasible.
As noted above, the coordination of cell divisions is of particular interest for analysis. The very first cell cycles in C. elegans are completely synchronized and fast (15 minutes) but become increasingly longer and asynchronous1. Thus, we focused our image analysis, using arivis Vision4D, on the precise description of the distinct early waves of cell division in our data set.
1 Koreth, J., van den Heuvel, S. Cell-cycle control in Caenorhabditis elegans: how the worm moves from G1 to S. Oncogene 24, 2756–2764 (2005).