A theory on the timing of cell fate decision in developing organs

Accurate patterning in developing tissues is one of the important steps to achieve normal development. Differently from static situations without tissue growth, relative positions of cells in growing tissues dynamically changes. Cell trajectories in growing tissues include different kinds of noises originating from the rearrangement of cell positions through cell division and embryo-to-embryo variability of tissue deformation dynamics itself. Such a kinematic randomness is magnified by the growth of tissues, which can be a barrier for achieving accurate spatial patterning in growing tissues. In this study, from the theoretical side, we propose a design criterion about when cell fates should be determined or when spatial patterning should be done in growing tissues in the presence of kinematic randomness, and apply the theory to chick limb developmental process.