ZFIN ID: ZDB-PUB-200229-15
Somite boundary determination in normal and clock-less vertebrate embryos
Naoki, H., Matsui, T.
Date: 2020
Source: Development, growth & differentiation   62(3): 177-187 (Review)
Registered Authors: Matsui, Takaaki
Keywords: ERK, computational model, developmental noise, live imaging, somitogenesis
MeSH Terms:
  • Animals
  • Body Patterning*
  • Extracellular Signal-Regulated MAP Kinases/metabolism
  • Fibroblast Growth Factors/metabolism
  • Models, Biological*
  • Signal Transduction
  • Somites/embryology*
  • Somites/metabolism*
  • Vertebrates/embryology*
  • Vertebrates/metabolism
PubMed: 32108939 Full text @ Dev. Growth Diff.
Vertebrate segments called somites are generated by periodic segmentation of the presomitic mesoderm (PSM). In the most accepted theoretical model for somite segmentation, the clock and wavefront (CW) model, a clock that ticks to determine particular timings and a wavefront that moves posteriorly are presented in the PSM, and somite positions are determined when the clock meets the posteriorly moving wavefront somewhere in the PSM. Over the last two decades, it has been revealed that the molecular mechanism of the clock and wavefront in vertebrates is based on clock genes including Hes family transcription factors and Notch effectors that oscillate within the PSM to determine particular timings and fibroblast growth factor (FGF) gradients, acting as the posteriorly moving wavefront to determine the position of somite segmentation. A clock-less condition in the CW model was predicted to form no somites; however, irregularly sized somites were still formed in mice and zebrafish, suggesting that this was one of the limitations of the CW model. Recently, we performed interdisciplinary research of experimental and theoretical biological studies and revealed the mechanisms of somite boundary determination in normal and clock-less conditions by characterization of the FGF/extracellular signal-regulated kinase (ERK) activity dynamics. Since features of the molecular clock have already been described in-depth in several reviews, we summarized recent findings regarding the role of FGF/ERK signaling in somite boundary formation and described our current understanding of how FGF/ERK signaling contributes to somitogenesis in normal and clock-less conditions in this review.