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Fig. 7 Internal MT network dynamics. (A) Time series visualizing a maximum intensity projection over a 30 µm of a developing embryo from (left to right) blastula, 50%, 70%, and 90% epiboly. The iMTN is visible in all these stages. AP = animal pole, VP = vegetal pole. Left and right images of the embryo are stitched together, scale bars 200 µm. See also Visualization 6. (B-D) Time series visualizing through maximum intensity projection over 26 µm the dynamics of iMTN-eMTN connections upon MOW passage. Before MOW passage the connection is clearly visible (white arrow, B), during MOW passage the connection is lost (C), and is re-established after MOW passage (white arrows, D). Scale bars 50 µm. See also Visualization 7. Single slice images relative to the same frame of (B) and (D) are visible in Supplementary Fig. S4. (E-G) Time series visualizing the XZ re-slice dynamics of iMTN-eYSN connection upon eYSN mitosis. Before the eYSN division the connection is present (E), during the division the connection is lost (F), and re-established after the division is completed (G). Scale bars 50 µm. All figures relative to dclk2-GFP embryos, and Orange HOT lookup table was used to ease iMTN visualization. (H) Updated model for the MT networks populating the zebrafish yolk between 512-cell and sphere stages. On the left side, the eMTN associated to the eYSN is subject to the MOW travelling toward the VP, exemplified as a belt of low-density MT. On the right side, the section view of the embryo is illustrated. The iMTN is present within the whole yolk cell. EVL = enveloping layer, DCs = deep cells. Representation not in scale.