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 (Tm, Tp, Tmd, and Tpd) in the feedback loops. (A–C) are slightly modified from [25].
|