A Yap-dependent mechanoregulatory program sustains cell migration for embryo axis assembly

Mechanical compression experiments were performed using a CellScale UniVert mechanical tester to simulate uniaxial deformation in live medaka embryos during gastrulation. Embryos were subjected to 20% axial deformation for 20 minutes under controlled displacement (±1 μm precision) using a custom compression chamber. The UniVert enabled real-time analysis of mechanoresponsive gene expression, showing that compression increased marcksl1b, lamc1, and ctgfa expression levels by 2–4× and elevated YAP–Tead sensor activity (Fig. 9A–C). This confirmed that intracellular tension directly activates YAP transcriptional feedback loops maintaining migratory cell mechanics.