Clocks, oscillation, and temporal delays in morphogenesis

Abstract

The presence and morphogenetic role of relatively autonomous pacemakers (“clocks”) during ontogeny is discussed. Although autonomous pacemakers in the strict sense seem nonexistent, the study of temporal processes is of great importance for recognizing the fundamental morphogenetic mechanisms. The most important and insufficiently understood questions in this field include the presence of hierarchies of characteristic times and their smoothing during critical developmental periods and also regulation of spatial processes via temporal delays.