In this paper, we present a model for pattern formation in developing organ
isms that is based on cellular oscillators (CO). An oscillatory process wit
hin cells serves as a developmental clock whose period is tightly regulated
by cell autonomous or non-autonomous mechanisms. A spatial pattern is gene
rated as a result of an initial temporal ordering of the cell oscillators f
reezing into spatial order as the clocks slow down and stop at different ti
mes or phases in their cycles. We apply a CO model to vertebrate somitogene
sis and show that we can reproduce the dynamics of periodic gene expression
patterns observed in the pre-somitic mesoderm. We also show how varying so
mite lengths can be generated with the CO model. We then discuss the model
in view of experimental evidence and its relevance to other instances of bi
ological pattern formation, showing its versatility as a pattern generator.
(C) 2001 Academic Press.