Quantitative cell morphology inC. elegansembryos reveals regulations of cell volume asymmetry

ABSTRACT The dynamics of cellular morphology throughout development are crucial for morphogenesis and organogenesis, yet their systematic characterization remains a significant challenge. By integrating both nuclear position and advanced cell membrane labeling, we develop a novel method that enables the segmentation of surfaces for over 95% of cells produced during Caenorhabditis elegans embryogenesis. With this method, we segment eight wild-type and four perturbed embryos. The output, including cell identity, shape, volume, surface and contact area, can be visualized using our custom software. We demonstrate that signaling interactions, such as Notch and Wnt, regulate not only the asymmetry of cell fate but also the asymmetry of cell volume in conjunction with mechanical compression. Furthermore, we find that the asymmetries of fate and volume are generally interconnected. ONE SENTENCE SUMMARY Systematic quantification of cell morphology with resolved cell lineage and cell fate in developing C. elegans embryo uncovers multimodal regulations of cell size. Potential Cover/Featured Image: Smiling “ghost” face of C. elegans embryo. Center: shown are skins (colored in red, dorsal view with anterior to the bottom) of a 400-celled C. elegans embryo. Cells not covered by the skins are colored in gray, green, blue, and transparent yellow, respectively. Internal and external circles: confocal fluorescence images (GFP for cell nucleus and mCherry for cell membrane) and reconstructed cell morphologies of the C. elegans embryo from the 2- to 550-cell stages respectively, connected with images of a C. elegans adult expressing the same markers.