[
Development & Evolution Meeting,
2008]
An understanding of the forces acting on cells in the early embryo can provide important information for how cells interact to determine their shapes, movements and fates. These forces can be both physical and genetic and can be intracellular or extracellular. The early Caenorhabditis elegans embryo provides an excellent environment to explore the forces acting during embryogenesis and to develop techniques that can be applied later to more advanced biological events. We report the development of a 4D GGH (Glazier-Granier-Hogeweg) model to simulate the 4-cell stage of embryogenesis. GGH modeling uses a Metropolis Monte Carlo algorithm to describe the evolution of systems based on the idea that many systems transform to minimize their overall energy. By using a fixed-lattice environment governed by the Hamiltonian, an overall energy equation, GGH modeling can simplify the description of cell-based phenomena. The early stages of embryogenesis offer an environment where components of the Hamiltonian can be identified and tested. Our Hamiltonian includes cell-cell adhesion, cell-shell contact, centromere rotation and elongation, and constraints of surface area and volume. Our GGH model allows for the incorporation of several biological components that have not be explored in previous models of C. elegans embryogenesis. In addition, several aspects of our model broaden the possible applications of GGH modeling.
[
Worm,
2016]
Dorsal intercalation is a coordinated cell migration event that rearranges hypodermal cells during C. elegans embryogenesis, and that resembles cell intercalation in many systems from flies to mice. Despite its conservation, the molecular mechanisms that govern dorsal intercalation in worms have remained elusive. Here, we comment on our recent publication, Walck-Shannon etal.,(1) which begins to spatially map the molecular requirements for intercalation. First, we provide a historical perspective on the factors that have previously hampered the study of dorsal intercalation. Next, we provide a summary of the molecular pathways identified in Walck-Shannon etal.,(1) pointing out surprises along the way. Finally, we consider the potential conservation of the molecular pathway we described and discuss future questions surrounding dorsal intercalation. Despite the challenges, dorsal intercalation is a process poised to advance our understanding of cell intercalation during morphogenesis throughout the animal kingdom.