Morphogensis of the NEM/forerunner cell cluster from 40% to 60% epiboly.
NEM cell segregation from other deep cells, movement to form forerunner cells.

 Play QuickTime movie of NEM cell morphogenesis:

1 MB (386x310) or 318 K (192x154)

Embryo is oriented with dorsal side to the left, animal pole toward the top. Embryo was labeled with SYTO-11 at dome stage to label NEM cells. Each image in the time lapse is a projection of multiple confocal images from a focus through z-stack.

Notice that the NEM cells (bright cells) are displaced toward the vegetal pole compared to the rest of the deep cells. The NEM cells are in the process of moving to the forerunner position in front of the margin of the blastoderm. Once the cells move to the forerunner cell position, they exhibit an increase in cell individual cell movement as well as a decrease in cellular cohesion with neighbors.

last updated 3/21/00 (JAR)