Xenbase Image ID: 132625

FIG. 5. Cell shapes can be indicative of morphogenetic mechanisms. If a cell sheet lengthens by cell shape change, then the cells must get longer in the dimension of sheet lengthening, whereas if lengthening occurs by cell rearrangement, intercalating cells become longer perpendicular to the direction of sheet lengthening (A). SEM of ventral mesoderm of stage 24 embryo reveals that cells have the long axis perpendicular to the A-P axis. Note the rosette arrangement at the upper right (B, arrow). Traced cell outlines of cells in B to illustrate length:width characteristics (B9). Bisected embryo with the mesodermal sheet extending beyond the ectoderm due to the fracture. Wedge-shaped cells (arrowhead) are underlying a rosette (arrow) in the ventral mesoderm of a stage 24 embryo (C). Traced cell outlines of wedge-shaped cells in C (C9). Rosettes appear to be correlated with wedge-shaped cells undergoing radial intercalation. In B and B9, anterior is to the left and dorsal is up. In C and C9, dorsal is up. Scale bar is 10 mm. Image published in: Larkin K and Danilchik MV (1999) Copyright © 1999. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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