PT - JOURNAL ARTICLE AU - Sawada, Atsushi AU - Shinya, Minori AU - Jiang, Yun-Jin AU - Kawakami, Atsushi AU - Kuroiwa, Atsushi AU - Takeda, Hiroyuki TI - Fgf/MAPK signalling is a crucial positional cue in somite boundary formation DP - 2001 Dec 01 TA - Development PG - 4873--4880 VI - 128 IP - 23 4099 - http://dev.biologists.org/content/128/23/4873.short 4100 - http://dev.biologists.org/content/128/23/4873.full SO - Development2001 Dec 01; 128 AB - The temporal and spatial regulation of somitogenesis requires a molecular oscillator, the segmentation clock. Through Notch signalling, the oscillation in cells is coordinated and translated into a cyclic wave of expression of hairy-related and other genes. The wave sweeps caudorostrally through the presomitic mesoderm (PSM) and finally arrests at the future segmentation point in the anterior PSM. By experimental manipulation and analyses in zebrafish somitogenesis mutants, we have found a novel component involved in this process. We report that the level of Fgf/MAPK activation (highest in the posterior PSM) serves as a positional cue within the PSM that regulates progression of the cyclic wave and thereby governs the positions of somite boundary formation.