Inducing presomitic mesoderm (PSM)-fated ES cells clarified that Ripply2 directly interacts with Tbx6 and degrades Tbx6 in proteasome-ubiquitin pathway by recruiting the 26S proteasome, which is a PSM-specific event to define the segment border during mouse somitogenesis.
Propagation, speed and shapes of genetic waves of expression during development can be modeled by a simple interplay between two transcriptional modules (dynamic/static), which explains robustness and precision of patterning.
In contrast to amniotes, zebrafish (ray-finned fish, teleost) centra are formed from specialised notochord sheath cells, and the segmental patterning of these cells is independent of the segmentation clock.
Time-lapse recording and theoretical analysis of individual cells isolated from the zebrafish segmentation clock reveal that they behave as self-sustained, autonomous oscillators with distinctive noisy dynamics.
Genetic manipulations show that endogenous transcription factors of the SoxB1 class act redundantly to maintain primed pluripotency and reveal differential effects on transitions between pluripotent and differentiation states.