English: Effect of treatment with 70kDa FN fragment on rate of somite formation and cell movements The video starts by showing two side-by-side bright-field image sequences of a control (BSA; upper panel) and 70kDa treated embryo (bottom panel), to compare rates of somite formation. FN matrix assembly disruption slows down and eventually halts somite formation and prevents cells from organizing into an aster of spindle-shaped centripetally aligned cells. In the last segment of the Video formation of pseudopodia is shown in “freezed-frames”, demonstrating that pseudopodial activity is not affected by the inhibition of FN fibrillogenesis. For more details refer to Figure 3 of the manuscript.