|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 6. Feedback regulation of snail expression by de-repressed WntD
expression. snail in situ probe, brown; wntD probe, blue.
The embryos shown in E,K and M were from an experiment using the
snail probe only; other embryos were from experiments using the
snail and wntD probes together. (A,B) Wild-type embryos
showing the patterns of snail and wntD expression. (A)
Ventral view of an early gastrula-stage embryo; (B) Sagittal view of a
mid-gastrula-stage embryo. (C) A snail mutant at germ-band extension
stage showing the de-repressed wntD and the reduced snail
mRNA expression. (D) A Df(3R)l26c embryo double stained for
wntD and snail. The snail pattern expanded into the
anterior and posterior regions, and the staining of wntD was absent,
demonstrating that it was a homozygous deficiency embryo. (E) A gastrulating
snail mutant embryo stained for snail mRNA alone. The mutant
embryo did not have a ventral furrow, although the cephalic furrow had already
formed. The lateral border of the snail expression (arrow) was fuzzy
in contrast to the sharp pattern observed in wild-type embryos. (F) A
double-mutant embryo stained for both snail and wntD. The
lateral borders of the snail pattern were sharp (arrow). (G,H) Higher
magnifications of the embryo shown in E, showing the cephalic furrow
(arrowhead) and the cellularization in the sagittal view (G), and the slightly
dorsally moved pole cells (arrow, H). (I,J) Higher magnification of the embryo
shown in F, showing that it was at a similar stage to the embryo shown in E.
(K) Ventral view of a snail mutant during early germ-band extension
showing the disappearing snail mRNA. (L) Ventral view of a similar
stage double-mutant embryo showing a higher level of the snail mRNA
staining. (M,N) Sagittal views of gastrulating embryos of the genotype
indicated. The snail staining disappeared more slowly in the
double-mutant background.
|
