Figure 1. Mapping of Temporal Oscillations into a Spatial Wave Pattern during Somite Segmentation, and a Model of the Oscillator Mechanism.

(A) The expression pattern of the oscillating gene deltaC in a zebrafish embryo at the ten-somite stage.

(B) In each cell of the presomitic mesoderm, it is proposed that a her1 or her7 autoinhibition negative feedback loop generates oscillations.

(C) Communication via the Delta-Notch pathway is proposed to keep oscillations in adjacent cells synchronized. The oscillations depend critically on the delays (T _m, T _p, T _md, and T _pd) in the feedback loops.

(A–C) are slightly modified from [25].