Related Experiment Video
Updated: Jul 29, 2026

Generation of Dispersed Presomitic Mesoderm Cell Cultures for Imaging of the Zebrafish Segmentation Clock in Single Cells
Published on: July 24, 2014
Periodic repression by the bHLH factor Hes7 is an essential mechanism for the somite segmentation clock
Yasumasa Bessho1, Hiromi Hirata, Yoshito Masamizu
1Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan. ybessho@virus.kyoto-u.ac.jp
Abstract:
Hes7, a bHLH gene essential for somitogenesis, displays cyclic expression of mRNA in the presomitic mesoderm (PSM). Here, we show that Hes7 protein is also expressed in a dynamic manner, which depends on proteasome-mediated degradation. Spatial comparison revealed that Hes7 and Lunatic fringe (Lfng) transcription occurs in the Hes7 protein-negative domains. Furthermore, Hes7 and Lfng transcription is constitutively up-regulated in the absence of Hes7 protein and down-regulated by stabilization of Hes7 protein. Thus, periodic repression by Hes7 protein is critical for the cyclic transcription of Hes7 and Lfng, and this negative feedback represents a molecular basis for the segmentation clock.
Related Concept Videos
Position-effect Variegation
RNA Polymerase II Accessory Proteins
Cis-regulatory Sequences
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Hedgehog Signaling Pathway
Circadian Rhythms and Gene Regulation

