title: Real-time imaging of the somite segmentation clock: revelation of unstable oscillators in the individual presomitic mesoderm cells.
abstract: Notch signaling components such as the basic helix-loop-helix gene Hes1 are cyclically expressed by negative feedback in the presomitic mesoderm (PSM) and constitute the somite segmentation clock. Because Hes1 oscillation occurs in many cell types, this clock may regulate the timing in many biological systems. Although the Hes1 oscillator is stable in the PSM, it damps rapidly in other cells, suggesting that the oscillators in the former and the latter could be intrinsically different. Here, we have established the real-time bioluminescence imaging system of Hes1 expression and found that, although Hes1 oscillation is robust and stable in the PSM, it is unstable in the individual dissociated PSM cells, as in fibroblasts. Thus, the Hes1 oscillators in the individual PSM cells and fibroblasts are intrinsically similar, and these results, together with mathematical simulation, suggest that cell-cell communication is essential not only for synchronization but also for stabilization of cellular oscillators.
authors.affiliation: Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Masamizu
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takashima
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nagahara
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Takenaka
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Kageyama
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000737:chemistry; D005347:Fibroblasts / Q000378:metabolism; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D008156:Luciferases / Q000378:metabolism; D008648:Mesoderm / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D009991:Oscillometry; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D051880:Receptors, Notch / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D019170:Somites / Q000166:cytology*; D013997:Time Factors; D000072056:Transcription Factor HES-1; D051153:Wnt Proteins / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004247:DNA; D018398:Homeodomain Proteins; D008156:Luciferases; D051880:Receptors, Notch; D000072056:Transcription Factor HES-1; D051153:Wnt Proteins; C489734:Hes1 protein, mouse