Somitogenesis is the process by which somites, blocks of mesoderm that give rise to a variety of connective tissues, are formed.
The model describes the splitting off of somites from the paraxial mesoderm as the result of oscillating expression of particular proteins and their gradients.
More technically, this means that somitogenesis occurs due to the largely cell-autonomous oscillations of a network of genes and gene products which causes cells to oscillate between a permissive and a non-permissive state in a consistently timed-fashion, like a clock.
[1] In particular, the cyclic activation of the Notch pathway appears to be of great importance in the wavefront-clock model.
[6] In addition, some cellular inter-dependency has been displayed in studies concerning the protein Sonic hedgehog (Shh) in somitogenesis.