(a,i) Brightfield/fluorescence images of Tg(gsc:GFP) wt (a) and
MZoep mutant embryos (i) at the end of gastrulation (bud
stage, 10hpf); arrowhead in (a) marks anterior edge of GFP (blue)-labeled
ppl.
(b,j) Anterior neurectoderm progenitor cells in a wt (b) and
MZoep embryo (j) at bud stage (10hpf) visualized by
whole-mount in situ hybridization of otx-2
mRNA.
(c,k) 2D tissue flow map indicating average velocities of ecto movements along
the animal-vegetal (AV) and left-right (LR) axis at the dorsal side of a wt (c;
7.1hpf) and MZoep embryo (k; 7.2hpf); local average ecto
velocities color-coded ranging from 0 (blue) to 2 (red) µm/min; positions
of all/leading edge ppl cells marked by black/green dots; boxed areas are used
for measurements in (d,l).
(d,l) Mean velocities along the AV axis (VAV) of ecto (red; right
y-axis; boxed area in c,k) and underlying ppl leading edge cells (green, left
y-axis) in wt (d; n=6 embryos) and MZoep embryos (l; n=4
embryos); 6-8hp; error bars, s.e.m..
(e) 3D directional correlation between ecto and ppl in a wt embryo at 7.1hpf;
color-coded correlation ranging from 1 (red, highest) to -1 (white, lowest); red
arrows indicate local averaged ecto velocities; boxed area was used for
measurements in (f).
(f) 3D average directional correlation between leading edge ppl and adjacent
neurectoderm cells (black boxed area in e) used for local correlation
(CL) calculation in wt embryos (n=6 embryos); 6-8hpf; error bars,
s.e.m.
(g,m) 2D tissue flow map of ecto cells showing time-averaged velocities (over
120min from 3 embryos) along the AV and LR axes at the dorsal side in wt (g) and
MZoep embryos (m); black dot in (g) marks position of ppl
leading edge.
(h,n) Schematic of ecto (red), ppl (green), and enveloping layer (EVL)/yolk
syncytial layer (YSL) movements (blue) in wt (h) and MZoep
embryos (n); arrows indicate AV and LR embryonic axes.
All embryos animal pole up; dorsal [b,j (dor) and h,n] and lateral [a,i and
b,j(lat)] views with dorsal right; scale bars, 200µm (a,b,i,j) and
100µm (c,e,k,m).