Mitosis in the early Drosophila embryo demonstrates spatial and temporal correlations in the form of wavefronts that travel across the embryo in each cell cycle. This coordinated phenomenon requires a signaling mechanism, which others have found to be calcium-dependent. We constructed theoretical models using either pure biochemical signaling through calcium diffusion or coupled chemical and mechanical signaling in an elastic medium. In the latter models, nuclei initiate mitosis when they experience stresses propagated by neighboring nuclei that have already divided. The mechanical models quantitatively capture the wavefront speed as it varies with cell cycle number. This cannot be acheieved with the purely biochemical signaling models. Furthermore, we can analyze nuclear displacements during these mitotic wavefronts to measure the elastic parameters of the medium. Their extracted values match and independently corroborate values required by the mechanical signaling model. These findings suggest that mechanical signaling may play an important role in mediating mitotic wavefronts. Additionally, we are currently studying a similar phenomenon in fetal chick heart tubes.Further reading:
- T. Idema and A. J. Liu, Mechanical signaling via nonlinear wavefront propagation in a mechanically-excitable medium, (2013).
- T. Idema, J. O. Dubuis, M. L. Manning, P. C. Nelson, and A. J. Liu, The syncytial Drosophila embryo as a mechanically excitable medium, (2013).