Statistical study of rapid mechanodependent cell movements in deformed explants of african clawed frog Xenopus laevis embryonic tissues

Abstract

Computer analysis of artificially deformed (stretched or compressed) double explants (sandwiches) of the blastocoel roof (BRs) and suprablastoporal region (SBRs) of African clawed frog Xenopus laevis early gastrula has been performed using frames of time-lapse microfilming. During the first 14 min after cutting off, the velocities and displacement angles of several hundreds of cells relative to one another, as well as to fixed points and the extension axis, were measured in the control and deformed samples. It has been found that the deformation of samples leads to a rapid reorientation of large cell masses and increase in the velocities of movements along the extension axes or perpendicularly to the compression axes. In addition, an increase in the velocities of mutual cell displacements in the stretched BRs and cell convergence to the extension axes have been observed. Comparison of different angular sectors demonstrates a statistically significant positive correlation between the mean velocities of cell movements and the number of cells moving within an individual sector. This suggests cooperativity of mechanodependent cell movements. In general, these results demonstrate an important role of mechanical factors in regulation of collective cell movements.