Notch signalling synchronizes the zebrafish segmentation clock but is not needed to create somite boundaries.

ABSTRACT: Somite segmentation depends on a gene expression oscillator or clock in the posterior presomitic mesoderm (PSM) and on read-out machinery in the anterior PSM to convert the pattern of clock phases into a somite pattern. Notch pathway mutations disrupt somitogenesis, and previous studies have suggested that Notch signalling is required both for the oscillations and for the read-out mechanism. By blocking or overactivating the Notch pathway abruptly at different times, we show that Notch signalling has no essential function in the anterior PSM and is required only in the posterior PSM, where it keeps the oscillations of neighbouring cells synchronized. Using a GFP reporter for the oscillator gene her1, we measure the influence of Notch signalling on her1 expression and show by mathematical m

SUBMITTER: Ozbudak EM 

PROVIDER: S-EPMC2222926 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature