title: Single-cell-resolution imaging of the impact of Notch signaling and mitosis on segmentation clock dynamics.
abstract: Vertebrate body segmentation is controlled by the segmentation clock, a molecular oscillator involving transcriptional oscillations of cyclic genes in presomitic mesoderm cells. The rapid and highly dynamic nature of this oscillating system has proved challenging for study at the single-cell level. We achieved visualization of clock activity with a cellular level of resolution in living embryos, allowing direct comparison of oscillations in neighbor cells. We provide direct evidence that presomitic mesoderm cells oscillate asynchronously in zebrafish Notch pathway mutants. By tracking oscillations in mitotic cells, we reveal that a robust cell-autonomous, Notch-independent mechanism resumes oscillations after mitosis. Finally, we find that cells preferentially divide at a certain oscillation phase, likely reducing the noise generated by cell division in cell synchrony and suggesting an intriguing relationship between the mitotic cycle and clock oscillation.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Emilie A
authors.initials: EA
authors.lastname: Delaune
authors.forename: Paul
authors.initials: P
authors.lastname: François
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Shih
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Amacher
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001683:Biological Clocks; D019521:Body Patterning; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D008938:Mitosis; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051880:Receptors, Notch; D029961:Zebrafish Proteins; C491619:her1 protein, zebrafish