NEM/forerunner cells:

NEM/forerunner cell position through epiboly

This figure shows a time series of still images of a SYTO-11 labeled NEM cell cluster from about 40% epiboly to 95% epiboly.

A,B. A bright field and confocal image of the embryo at 35-40% epiboly. Notice (in B) the two brightly labeled NEM cells (white arrow) at the margin of the blastoderm. The two cells directly to the left have SYTO-11 labeling that is much weaker. The edge of the blastoderm is marked by arrowheads in the rest of the figure. t=0:00 hr.

C,D. The same embryo about 5 minutes later. Now there are four brightly labeled NEM cells (white arrow, compare with previous panel). t=0:05 hr.

E,F. The embryo has started gastrulation (about 60-65% epiboly). The NEM/forerunner cells (white arrow) do not involute and remain at the margin of the blastoderm. The embryonic shield is forming just underneath them. t=2:50 hr.

G,H. Embryo at 70% epiboly. The NEM/forerunner cells (white arrow) are in front of the margin at this time. t=4:30 hr.

I,J. Embryo at 80% epiboly. The forerunner cells remain at the most posterior part of the forming embryonic axis (just posterior to the differentiating notochord (black arrows in I)). t=5:30 hr.

K,L. Embryo at 95% epiboly. The forerunner cells (large arrow) remain just posterior to the notochord rudiment (small arrows). Incorpration of the forerunner cells into the tail rudiment has just begun.

last updated 3/21/00(JAR)